Version 3.3.2 Technical Reference Guide for Microwave Networks AT332_TRM_E0 AT332_TRM_E0AT332_TRM_E0 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Release: AT332_TRM_E0 (October 2016) © Copyright 1997-2016 Forsk. All Rights Reserved. Published by: Forsk 7 rue des Briquetiers 31700 Blagnac, France Tel: +33 562 747 210 Fax: +33 562 747 211 The software described in this document is provided under a licence agreement. The software may only be used or copied under the terms and conditions of the licence agreement. No part of the contents of this document may be reproduced or transmitted in any form or by any means without written permission from the publisher. The product or brand names mentioned in this document are trademarks or registered trademarks of their respective registering parties. Third party services that are not part of Atoll are governed by the terms and conditions of their respective providers, which are subject to change without notice. The publisher has taken care in the preparation of this document, but makes no expressed or implied warranty of any kind and assumes no responsibility for errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of the use of the information contained herein. AT332_TRM_E0 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Table of Contents Table of Contents Atoll 3.3.2 Technical Reference Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 1 Antennas and Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 1.1 Calculation of Azimuth and Tilt Angles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 1.2 Antenna Pattern 3D Interpolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 1.3 Antenna Diameter Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2 Microwave Propagation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 2.1 Ground Altitude Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 2.2 Clutter Height Determination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 2.3 Resolution of the Extracted Profiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2.4 2.4.1 2.4.2 2.4.3 2.4.4 2.4.4.1 2.4.4.2 2.4.4.3 2.4.4.4 2.4.4.5 2.4.4.6 2.4.4.7 2.4.5 2.4.6 2.4.6.1 2.4.6.2 2.4.6.3 Microwave Propagation Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Path Length. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Profile Extraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Free Space Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Diffraction Loss. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Knife-Edge Diffraction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 3 Knife-Edge Deygout Method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Epstein-Peterson Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Deygout Method with Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Millington Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Full Deygout Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 ITU 452-11 Recommendation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Atmospheric Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Tropospheric Scatter Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 ITU-R P.617-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 ITU-R P. 452 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Simplified Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 3 3.1 3.1.1 3.1.2 3.1.2.1 3.1.2.2 3.1.2.3 3.1.2.4 3.1.2.5 3.1.2.6 3.1.2.7 3.1.2.8 3.1.3 3.1.3.1 3.1.3.1.1 3.1.3.1.2 3.1.3.1.3 3.1.3.1.4 3.1.3.2 3.1.3.2.1 3.1.3.2.2 3.1.3.2.3 Microwave Link Networks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 Link Budget and Interference Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Link Budget Calculation Details. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Nominal Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Coordinated Power. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Transmission Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 EIRP (Equivalent Isotropic Radiated Power) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Reception Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Received Signal Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Thermal Fade Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Signal Enhancement Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Interference Calculation Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Single Interference Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Interference Signal Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Carrier to Interference Ratio (C/I) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Threshold Degradation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Effective Thermal Fade Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Multiple Interference Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Total Interference Signal Level in Clear Air Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Total Interference Signal Level in Rain Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Total Carrier to Interference Ratio (C/I) in Clear Air Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 3 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Table of Contents 4 © 2016 Forsk. All Rights Reserved. 3.1.3.2.4 3.1.3.2.5 3.1.3.2.6 3.1.3.2.7 3.1.3.2.8 Total Carrier to Interference Ratio (C/I) in Rain Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34 Total Threshold Degradation in Clear Air Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34 Total Threshold Degradation in Rain Conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34 Total Effective Thermal Fade Margin in Clear Air Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 Total Effective Thermal Fade Margin in Rain Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 3.2 3.2.1 3.2.2 3.2.2.1 3.2.2.1.1 3.2.2.1.2 3.2.2.1.3 3.2.2.2 3.2.2.3 3.2.2.4 Performance Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 Input. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 ITU-R P.530 Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 Total Outage Probability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 Total Outage Probability in Rain Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 Total Outage Probability in Clear-Air Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 Total Outage Probability due to Equipment Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36 Quality Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36 Availability Performance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36 Global Annual Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36 3.3 3.3.1 3.3.2 3.3.2.1 3.3.2.1.1 3.3.2.1.2 3.3.2.1.3 3.3.2.1.4 3.3.2.1.5 3.3.2.1.6 3.3.2.2 3.3.3 3.3.3.1 3.3.3.1.1 3.3.3.1.2 3.3.3.1.3 3.3.3.1.4 3.3.3.1.5 3.3.3.1.6 3.3.3.2 3.3.3.3 3.3.4 3.3.4.1 3.3.4.1.1 3.3.4.1.2 3.3.4.1.3 Propagation in Rain Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36 Input. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36 ITU-R P.530-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 Rain Fade Margin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 Rain Coefficients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 Rain Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 Effective Path Length. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 Rain Fade Margin Exceeded for 0.01% of the Average Year . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 Rain Fade Margin Exceeded for p% of the Average Year . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 Rain Fade Margin Exceeded for pw% of the Average Worst Month . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 Total Outage Probability due to Rain for the Average Year. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 ITU-R P.530-8, ITU-R P.530-10, ITU-R P.530-11, ITU-R P.530-12 and ITU-R P.530-13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 Rain Fade Margin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 Rain Coefficients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 Rain Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 Effective Path Length. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 Rain Fade Margin Exceeded for 0.01% of the Average Year . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 Rain Fade Margin Exceeded for p% of the Average Year . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 Rain Fade Margin Exceeded for pw% of the Average Worst Month . . . . . . . . . . . . . . . . . . . . . . . . . . . .39 Outage Probability due to Rain for the Average Year . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39 Outage Probability due to XPD Reduction for the Average Year. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39 Crane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 Rain Fade Margin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 Rain Coefficients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 Rain Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 Rain Fade Margin Exceeded for p% of the Average Year . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 3.4 3.4.1 3.4.2 3.4.2.1 3.4.2.1.1 3.4.2.1.2 3.4.2.1.3 3.4.2.1.4 3.4.2.1.5 3.4.2.1.6 3.4.2.1.7 3.4.2.2 3.4.2.2.1 3.4.2.2.2 3.4.2.3 3.4.2.3.1 3.4.2.3.2 3.4.2.4 3.4.2.4.1 3.4.3 3.4.3.1 3.4.3.1.1 3.4.3.1.2 3.4.3.1.3 Propagation in Clear-Air Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41 Input. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41 Fading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42 Frequency Non-Selective Fading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42 ITU-R P.530-5 - Method for Initial Planning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42 ITU-R P.530-5 - Method for Detailed Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45 ITU-R P.530-8 - Method for Initial Planning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47 ITU-R P.530-10, ITU-R P.530-11 and ITU-R P.530-12 - Method for Initial Planning . . . . . . . . . . . . . . . .50 ITU-R P.530-10, ITU-R P.530-11 and ITU-R P.530-12 - Method for Detailed Planning. . . . . . . . . . . . . .51 ITU-R P.530-13 - Method for Initial Planning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52 ITU-R P.530-13 - Method for Detailed Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54 Frequency Selective Fading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55 ITU-R P.530-8, ITU-R P.530-10 and ITU-R P.530-11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55 ITU-R P.530-12 and ITU-R P.530-13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56 Vigants-Barnett . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57 Method for Initial Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57 Method for Detailed Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57 CCIR Report 338 (KQ factor) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58 Method for Detailed Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58 Signal Enhancement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60 ITU-R P.530-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60 Thermal Fade Margin Exceeded for 0.01% of the Average Worst Month . . . . . . . . . . . . . . . . . . . . . . .60 Thermal Fade Margin Exceeded for 0.01% of the Average Year . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60 Selection Process Between Method for Small Percentage of Time and Method for Various Percentage AT332_TRM_E0 3.4.3.1.4 3.4.3.1.5 3.4.3.2 3.4.3.2.1 3.4.3.2.2 3.4.3.2.3 3.4.3.2.4 3.4.3.2.5 3.4.4 3.4.4.1 3.4.4.1.1 3.4.4.1.2 3.4.4.1.3 3.4.5 3.4.5.1 3.4.5.1.1 3.4.5.1.2 3.4.5.1.3 3.4.5.2 3.4.5.2.1 3.5 3.5.1 3.5.2 3.5.2.1 3.5.2.2 3.5.2.3 3.5.2.4 3.5.2.5 3.5.2.6 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Table of Contents of Time61 Method for Small Percentage of Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Method for Various Percentage of Time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 ITU-R P.530-8, ITU-R P.530-10, ITU-R P.530-11, ITU-R P.530-12 and ITU-R P.530-13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Thermal Fade Margin Exceeded for 0.01% of the Average Worst Month . . . . . . . . . . . . . . . . . . . . . . . 63 Thermal Fade Margin Exceeded for 0.01% of the Average Year. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Selection Process Between Method for Small Percentage of Time and Method for Various Percentage of Time64 Method for Small Percentage of Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Method for Various Percentage of Time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 XPD Reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 ITU-R P.530-8, ITU-R P.530-10 and ITU-R P.530-11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Multipath Parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Cross-Polarisation Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Outage Probability due to XPD Reduction for the Average Worst Month . . . . . . . . . . . . . . . . . . . . . . . 67 Diversity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 ITU-R P.530-8, ITU-R P.530-10, ITU-R P.530-11, ITU-R P.530-12 and ITU-R P.530-13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Space Diversity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Frequency Diversity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 Space and Frequency Diversity (Two Receivers) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Vigants-Barnett . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Space Diversity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Surface Reflection Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 ITU-R P.530-10, ITU-R P.530-11, ITU-R P.530-12 and ITU-R P.530-13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 Surface Reflection Point Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 Difference in Path Length Between Direct and Reflected Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 Surface Reflection Coefficient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 Effective Surface Reflection Coefficient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 Thermal Fade Margin Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 Attenuation Graphs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 5 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Table of Contents 6 © 2016 Forsk. All Rights Reserved. Atoll 3.3.2 Technical Reference Guide for Microwave Networks Introduction AT332_TRM_E0 Atoll 3.3.2 Technical Reference Guide This Technical Reference Guide is aimed at radio network engineers with an advanced knowledge of Atoll and radio network planning. It provides detailed information about the inner workings and formulas that are implemented by Atoll Microwave. About Atoll Atoll is a 64-bit multi-technology wireless network design and optimisation platform. Atoll is open, scalable, flexible, and supports wireless operators throughout the network life cycle, from initial design to densification and optimisation. Atoll Microwave is a complete backhaul and microwave link planning solution based on the leading Atoll platform, which includes a high performance GIS and advanced data and user management features. Atoll Microwave can share its site database with Atoll radio planning and optimisation modules, thus allowing easy data consistency management across the operator organisation. Atoll’s integration and automation features help operators smoothly automate planning and optimisation processes through flexible scripting and SOA-based mechanisms. Atoll supports a wide range of implementation scenarios, from standalone to enterprise-wide server-based configurations. If you are interested in learning more about Atoll, please contact your Forsk representative to inquire about our training solutions. About Forsk Forsk is an independent company providing radio planning and optimisation software solutions to the wireless industry since 1987. In 1997, Forsk released the first version of Atoll, its flagship radio planning software. Since then, Atoll has evolved to become a comprehensive radio planning and optimisation platform and, with more than 7000 installed licenses worldwide, has reached the leading position on the global market. Atoll combines engineering and automation functions that enable operators to smoothly and gradually implement SON processes within their organisation. Today, Forsk is a global supplier with over 450 customers in 120 countries and strategic partnerships with major players in the industry. Forsk distributes and supports Atoll directly from offices and technical support centres in France, USA, and China as well as through a worldwide network of distributors and partners. Since the first release of Atoll, Forsk has been known for its capability to deliver tailored and turn-key radio planning and optimisation environments based on Atoll. To help operators streamline their radio planning and optimisation processes, Forsk provides a complete range of implementation services, including integration with existing IT infrastructure, automation, as well as data migration, installation, and training services. Getting Help The online help system that is installed with Atoll is designed to give you quick access to the information you need to use the product effectively. It contains the same material as the Atoll 3.3.2 User Manual. You can browse the online help from the Contents view, the Index view, or you can use the built-in Search feature. You can also download manuals from the Forsk web site at: http://www.forsk.com/MyForskAccount/ Printing Help Topics You can print individual topics or chapters from the online help. To print help topics or chapters: 1. In Atoll, click Help > Help Topics. 2. In the Contents tab, expand the table of contents. 3. Right-click the section or topic that you want to print and click Print. The Print Topics dialog box appears. 4. In the Print Topics dialog box, select what you want to print: • • If you want to print a single topic, select Print the selected topic. If you want to print an entire section, including all topics and sections in that section, select Print the selected heading and all subtopics. 7 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Introduction © 2016 Forsk. All Rights Reserved. 5. Click OK. About Atoll Documentation The following PDF manuals are available for Atoll and Atoll Microwave and can be downloaded from the Forsk web site at: http://www.forsk.com/MyForskAccount/ • • • • • • Atoll User Manual Atoll Administrator Manual Atoll Data Structure Reference Guide Atoll Technical Reference Guide Atoll Task Automation Guide Atoll Model Calibration Guide To read PDF manuals, download Adobe Reader from the Adobe web site at: http://get.adobe.com/reader/ Hardcopy manuals are also available. For more information, contact to your Forsk representative. Contacting Technical Support Forsk provides global technical support for its products and services. To contact the Forsk support team, visit the My Forsk web site at: http://www.forsk.com/MyForskAccount/ Alternatively, depending on your geographic location, contact one of the following support teams: • Forsk Head Office For regions other than North and Central America and China, contact the Forsk Head Office support team: • • • Tel.: +33 562 747 225 Fax: +33 562 747 211 Email:
[email protected] Opening Hours: Monday to Friday 9.00 am to 6.00 pm (GMT +1:00) • Forsk US For North and Central America, contact the Forsk US support team: • • • Tel.: 1-888-GO-ATOLL (1-888-462-8655) Fax: 1-312-674-4822 Email:
[email protected] Opening Hours: Monday to Friday 8.00 am to 8.00 pm (Eastern Standard Time) • Forsk China For China, contact the Forsk China support team: • • • Tel: +86 20 8557 0016 Fax: +86 20 8553 8285 Email:
[email protected] Opening Hours: Monday to Friday 9.00am to 5.30pm (GMT+08:00) Beijing, Chongqing, Hong Kong, Urumqi. 8 Chapter 1 Antennas and Equipment This chapter covers the following topics: • "Calculation of Azimuth and Tilt Angles" on page 11 • "Antenna Pattern 3D Interpolation" on page 12 • "Antenna Diameter Calculation" on page 13 Atoll 3.3.2 Technical Reference Guide for Microwave Networks ©2016 Forsk. All Rights Reserved 10 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 1: Antennas and Equipment AT332_TRM_E0 1 Antennas and Equipment To determine the transmitter antenna attenuation, Atoll calculates the accurate azimuth and tilt angles and performs 3D interpolation of the horizontal and vertical patterns. 1.1 Calculation of Azimuth and Tilt Angles From the direction of the transmitter antenna and the receiver position relative to the transmitter, Atoll determines the receiver position relative to the direction of the transmitter antenna (i.e. the direction of the transmitter-receiver path in the transmitter antenna coordinate system). aTx and eTx are respectively the transmitter (Tx) antenna azimuth and tilt in the coordinate system S 0 x y z . aRx and eRx are respectively the azimuth and tilt of the receiver (Rx) in the coordinate system S 0 x y z . d is the distance between the transmitter (Tx) and the receiver (Rx). Figure 1.1: Azimuth and Tilt Calculation In the coordinate system S 0 x y z , the receiver coordinates are: cos e Rx sin a Rx d x Rx y Rx = z Rx cos e Rx cos a Rx d (1) – sin e Rx d Let az and el respectively be the azimuth and tilt of the receiver in the transmitter antenna coordinate system S Tx x'' y'' z'' . These angles describe the direction of the transmitter-receiver path in the transmitter antenna coordinate system. Therefore, the receiver coordinates in S Tx x'' y'' z'' are: x'' Rx y'' Rx = z'' Rx cos el sin az d cos el cos az d – sin el d (2) According to the figure above, we have the following relations: x' y' = z' cos a Tx – sin a Tx 0 x sin a Tx cos a Tx 0 y z 0 0 1 (3) and 11 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 1: Antennas and Equipment 1 0 0 x'' x' y'' = 0 cos e Tx – sin e Tx y' z'' z' 0 sin e Tx cos e Tx © 2016 Forsk. All Rights Reserved. (4) Therefore, the relation between the system S 0 x y z and the transmitter antenna system S Tx x'' y'' z'' is: 1 0 0 cos a Tx – sin a Tx 0 x'' x y'' = 0 cos e Tx – sin e Tx sin a Tx cos a Tx 0 y z'' z 0 sin e Tx cos e Tx 0 0 1 (5) We get, x'' y'' = z'' cos a Tx – sin a Tx 0 x cos e Tx sin a Tx cos e Tx cos a Tx – sin e Tx y z sin e Tx sin a Tx sin e Tx cos a Tx cos e Tx (6) Then, substituting the receiver coordinates in the system S0 from Eq. (1) and the receiver coordinates in the system STx from Eq. (2) in Eq. (6) leads to a system where two solutions are possible: 1st solution: If a Rx = a Tx , then az = 0 and el = eRx – e Tx 2nd solution: If a Rx a Tx , then 1 az = atan ---------------------------------------------------------------------------------------cos e Tx sin e Tx tan e Rx ----------------------------------- + ---------------------------------------------tan a Rx – a Tx sin a Rx – a Tx and cos e Tx tan e Rx – sin e Tx - + ---------------------------------------------- el = atan sin az ---------------------------------sin a Rx – a Tx tan a Rx – a Tx If sin az sin a Rx – a Tx 0 , then az = az + 180 1.2 Antenna Pattern 3D Interpolation The direction of the transmitter-receiver path in the transmitter antenna coordinate system is given by angle values, az and el. Atoll considers these values in order to determine transmitter antenna attenuations in the horizontal and vertical patterns. It reads the attenuation H(az) in the horizontal pattern for the calculated azimuth angle az and the attenuation V(el) in the vertical pattern for the calculated tilt angle el. Then, it calculates the antenna total attenuation, L antTx az el . 180 – az az L antTx az el = H az – ----------------------- H 0 – V el + --------- H 180 – V 180 – el 180 180 Atoll assumes that the horizontal and vertical patterns are cross-sections of a 3D pattern. In other words, the description of the antenna pattern must satisfy the following: H(0)=V(0) and H()=V() In case of an electrical tilt, , the horizontal pattern is a conical section with an elevation of degrees off the horizontal plane. Here, horizontal and vertical patterns must satisfy the following: H(0)=V() and H()=V(-) If the constraints listed above are satisfied, this implies that: • • Interpolated horizontal and vertical patterns respectively fit in with the entered horizontal and vertical patterns, even in case of electrical tilt, and The contribution of both the vertical pattern back and front parts are taken into account. Otherwise, only the second point is guaranteed. • • • 12 This interpolation is performed in dBs. Angle values in formulas are stated in degrees. This interpolation is not used with 3D antenna patterns. Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 1: Antennas and Equipment AT332_TRM_E0 1.3 Antenna Diameter Calculation Atoll automatically calculates the antenna diameter from the antenna gain and the average operating frequency. The antenna diameter is calculated using the following equation for a radiation efficiency of 55 %: G ant = 20 LogD antenna + 20 f – 42,2 , which gives: D antenna = 10 G ant ----------- 20 - + 2,11 – Logf Where, D antenna is the antenna diameter (in m), G ant is the antenna gain (in dBi), f is the average frequency (in MHz). It is calculated as follows: f max – f min f = f min + -----------------------2 f min is the minimum frequency of the frequency band (in MHz), f max is the maximum frequency of the frequency band (in MHz). 13 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 1: Antennas and Equipment 14 © 2016 Forsk. All Rights Reserved. Chapter 2 Microwave Propagation This chapter covers the following topics: • "Ground Altitude Determination" on page 17 • "Clutter Height Determination" on page 17 • "Resolution of the Extracted Profiles" on page 18 • "Microwave Propagation Model" on page 18 Atoll 3.3.2 Technical Reference Guide for Microwave Networks ©2016 Forsk. All Rights Reserved 16 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 2: Microwave Propagation AT332_TRM_E0 2 Microwave Propagation 2.1 Ground Altitude Determination Atoll determines reception and transmission site altitude from Digital Terrain Model map. The method used to evaluate site altitude is based on a bilinear interpolation. It is described below. Let us suppose a site S located inside a bin. Atoll knows the altitudes of four bin vertices, S’1, S’’1, S’2 and S’’2, from the DTM file (centre of each DTM pixel). Figure 2.1: Ground Altitude Determination - 1 1. Atoll draws a vertical line through S. This line respectively intersects (S’1,S’’1) and (S’2, S’’2) lines at S1 and S2. Figure 2.2: Ground Altitude Determination - 2 2. Atoll determines the S1 and S2 altitudes using a linear interpolation method. Figure 2.3: Ground Altitude Determination - 3 3. Atoll performs a second linear interpolation to evaluate the S altitude. Figure 2.4: Ground Altitude Determination - 4 2.2 Clutter Height Determination Some propagation models need clutter class and clutter height as information at receiver or along a transmitter-receiver profile. Atoll uses clutter classes file to determine the clutter class. To evaluate the clutter height, Atoll uses clutter heights file if available in the ATL document; clutter height of a site is the height of the nearest point in the file. Example: Let us suppose a site S. In the clutter heights file, Atoll reads clutter heights of four points around the site, S’1, S’’1, S’2 and S’’2. Here, the nearest point to S is S”2; therefore Atoll takes the S”2 clutter height as clutter height of S. 17 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 2: Microwave Propagation © 2016 Forsk. All Rights Reserved. Figure 2.5: Clutter Height If you do not have any clutter height file, Atoll takes clutter height information in clutter classes file. In this case, clutter height is an average height related to a clutter class. 2.3 Resolution of the Extracted Profiles Geographic profile resolution depends on resolution of geographic data used by the propagation model (DTM and/or clutter). The selected profile resolution does not depend on the geographic layer order. • Example 1 (Using the Microwave Propagation Model) A DTM map with a 40 m resolution and a clutter heights map with a 20 m resolution are available. The profile resolution will be 20 m. It means that Atoll will extract geographic information, ground altitude and clutter height, every 20 m. To get ground altitude every 20 m, Atoll uses the bilinear interpolation method described in "Ground Altitude Determination" on page 17. Clutter heights are read from the clutter heights map. Atoll takes the clutter height of the nearest point every 20 m. • Example 2 (Using the Microwave Propagation Model) A DTM map with a 40 m resolution and a clutter classes map with a 20 m resolution are available. No clutter height file has been imported in the document. The profile resolution will be 20 m. It means that Atoll will extract geographic information, ground altitude and clutter height, every 20 m. To get ground altitude every 20 m, Atoll uses the bilinear interpolation method described in "Ground Altitude Determination" on page 17. Atoll uses the clutter classes map to determine clutter height. Every 20 m, it determines clutter class and takes associated average height. 2.4 Microwave Propagation Model The microwave propagation model is used to compute the total loss along the propagation path. The path is defined by the positions of the transmitter site and the receiver site, their antenna heights, and the terrain profile between them. The microwave propagation model considers the following losses: • • • • Free space loss, Diffraction loss, Atmospheric loss, Tropospheric scatter loss, 2.4.1 Path Length The total length is calculated along the great-circle as follows: dkm = nang 2 4,10 8 2 - + zkm 1 – zkm 2 ---------------------------------2 zkm i is the total height (DTM + antenna height) of each extremity. nang = 18 2 2 + cos latitude 1 cos latitude 2 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 2: Microwave Propagation AT332_TRM_E0 R min sin lati 3 cos atan ---------- ---------------------- R max cos lati --------------------------------------------------------------------------------------------------- latitude 1 – latitude 2 = R max R moy cos lati 2 R min R min sin lati 3 cos atan ---------- ---------------------- R max cos lati R max = ----------- ------------------------------------------------------------------------- longitude 1 – longitude 2 R moy cos lati latitude 1 + latitude 2 where lati = ----------------------------------------------------2 and R min = 6356,912 km , R moy = 6366,2 km , R max = 6378,388 km . 2.4.2 Profile Extraction The profile is extracted from DTM and clutter files. The points along the profile are regularly spaced at , which is: Total Length = --------------------------------n – 1 Where, Total Length is the path length along the great circle. Total Length n is the number of points of the profile. n is given by : n = long ---------------------------------- . Step + 1 Step is the profile extraction resolution (see "Resolution of the Extracted Profiles" on page 18). Clutter heights at the transmitter and the receiver are always equal to 0. 2.4.3 Free Space Loss Atoll calculates L model1 (in dB). L model1 = K 1 + K 2 log d + K 3 log f with, K1: constant offset (dB). K2: multiplicative factor for log(d) d: distance between the receiver and the transmitter sites (km) K3: multiplicative factor for log(f) f: frequency of transmission (MHz) The default values for K1, K2 and K3 coefficients are respectively set to 32.4, 20 and 20. Therefore, L model1 is equal to free space loss ( L b0 ). L b0 = 32,4 + 20 log f + 20 log d In case of a link (AB) with one or two repeaters (P and Q), Atoll calculates free space loss for each section of the link (AP, PQ and QB) and then, considers the sum. 19 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 2: Microwave Propagation © 2016 Forsk. All Rights Reserved. 2.4.4 Diffraction Loss General method for one or more obstacles (knife-edge diffraction) is used to evaluate diffraction losses ( L d ) (dB) over the transmitter-receiver profile. Six construction methods are implemented in Atoll: • • • • • • Deygout Epstein Peterson Deygout with correction (ITU 526-5) Millington ITU 452-11 Full Deygout All of the construction methods are based on the same physical principle but differ in the way they consider one or several obstacles. According to the selected option in the Parameters tab of the model’s properties dialog, i.e., Use Clutter Heights = Yes or No, you can consider the following along the transmitter-receiver profile: • Ground altitude and clutter height (Consider heights in diffraction option), In this case, Atoll uses clutter height information from clutter heights files if available in the .atl document. Otherwise, it considers average clutter height specified for each clutter class in the clutter classes file description. • Or, only ground altitude. Refractivity Factor All methods except the Millington method use the refractivity coefficient k as a user input. The refractive index in the troposphere drops gradually with the altitude and the resulting refraction causes the radio horizon to appear 1.33 times further than the geographic horizon. 2.4.4.1 Knife-Edge Diffraction The procedure checks whether a knife-edge obstructs the first Fresnel zone constructed between the transmitter and the receiver. The diffraction loss, J(), depends on the obstruction parameter (), which corresponds to the ratio of the obstruction height (h) and the radius of the Fresnel zone (R). Figure 2.6: Knife-Edge Diffraction R = c0 n d1 d2 -------------------------------f d1 + d2 Where, n is the Fresnel zone index, c0 is the speed of light (2.99792 x108 m/s), f is the frequency in Hz d1 is the distance from the transmitter to obstacle in m, 20 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 2: Microwave Propagation AT332_TRM_E0 d2 is the distance from obstacle to receiver in m. h We have: = --r Where, Rr = -----2 h is the obstruction height (height from the obstacle top to the Tx-Rx axis). Hence, 2 For 1 knife-edge method, if – 0,7 , J = 6,9 + 20 log – 0,1 + 1 + – 0,1 Else, J = 0 In case of multiple-knife edge method, the minimum required to estimate diffraction loss is -0.78. 2.4.4.2 3 Knife-Edge Deygout Method The Deygout construction, limited to a maximum of three edges, is applied to the entire profile from transmitter to receiver. This method is used to evaluate path loss incurred by multiple knife-edges. Deygout method is based on a hierarchical knifeedge sorting used to distinguish the main edges, which induce the largest losses, and secondary edges, which have a lesser effect. The edge hierarchy depends on the obstruction parameter () value. 1 Obstacle Figure 2.7: Deygout Construction – 1 Obstacle A straight line between transmitter and receiver is drawn and the height of the obstacle above the Tx-Rx axis, hi, is calculated. The obstruction position, di, is also recorded. i are evaluated from these data. The point with the highest value is termed the principal edge, p, and the corresponding loss is J(p). Therefore, we have DiffractionLoss = J P 3 Obstacles Then, the main edge (point p) is considered as a secondary transmitter or receiver. Therefore, the profile is divided in two parts: one half profile, between the transmitter and the knife-edge section, another half, constituted by the knife-edgereceiver section. 21 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 2: Microwave Propagation © 2016 Forsk. All Rights Reserved. Figure 2.8: Deygout Construction – 3 Obstacles The same procedure is repeated on each half profile to determine the edge with the higher . The two obstacles found, (points t and r), are called ‘secondary edges’. Losses induced by the secondary edges, J(t) and J(r), are then calculated. Once the edge hierarchy is determined, the total loss is evaluated by adding all the intermediary losses obtained. Therefore, if P 0 we have DiffractionLoss = J P + J t + J r Otherwise, If P – 0,7 , DiffractionLoss = J P 2.4.4.3 Epstein-Peterson Method The Epstein-Peterson construction is limited to a maximum of three edges. First, Deygout construction is applied to determine the three main edges over the whole profile as described above. Then, the main edge height, hp, is recalculated according to the Epstein-Peterson construction. hp is the height above a straight line connecting t and r points. The main edge position dp is recorded and p and J(p) are evaluated from these data. Figure 2.9: Epstein-Peterson Construction Therefore, we have DiffractionLoss = J P + J t + J r 2.4.4.4 Deygout Method with Correction The Deygout method with correction (ITU 526-5) is based on the Deygout construction (3 obstacles) plus an empirical correction, C. Therefore, If P 0 , we have DiffractionLoss = J P + J t + J r + C Otherwise DiffractionLoss = J P + C 22 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 2: Microwave Propagation AT332_TRM_E0 2.4.4.5 Millington Method The Millington construction, limited to a single edge, is applied over the entire profile. Two horizon lines are drawn at the transmitter and at the receiver. A straight line between the transmitter and the receiver is defined and the height of the intersection point between the two horizon lines above the Tx-Rx axis, hh, is calculated. The position dh is recorded and then, from these values, h and J(h) are evaluated using the same previous formulas. Therefore, we have DiffractionLoss = J h Figure 2.10: Millington Construction 2.4.4.6 Full Deygout Method According to the profile and antenna heights, diffraction can be classified as: • • • Line of sight: full Fresnel ellipsoid clearance Trans-horizon: optical path is obstructed Sub-diffraction: line-of sight with no full Fresnel ellipsoid clearance. Standard Deygout Algorithm searches the main obstacle which obstructs the optical path. Whenever such an obstacle exists, two other obstacles are searched: • • Between Tx and this main obstacle Between this main obstacle and Rx The 3 losses are added. Only the main peak is drawn on the profile and the loss is the sum of the 3 peaks. If the main obstacle does not obstruct the optical path but just penetrates the Fresnel Ellipsoid, the 2 secondary obstacles are not taken into account. Full Deygout algorithm always adds the secondary obstacles losses. Sub-diffraction case is more precisely computed with this method compared to Standard Deygout algorithm. So, in the full Deygout method, for any "sufficient" P – 0,7 p , DiffractionLoss = J P + J t + J r . Remember that for each case above (standard and full Deygout methods), penetrating the Fresnel Ellipsoid means that the distance between the earth (DTM + clutter height) and the optical path is less than 60% of the Fresnel ellipsoid radius at this point. 2.4.4.7 ITU 452-11 Recommendation The ITU-R P.452 recommendations are used to evaluate the microwave interference between links. Various losses which do not affect the useful signal are taken into account and described in "Link Budget and Interference Analysis" on page 31. Diffraction loss calculation between an interfering transmitter and a victim receiver is slightly different from the other methods described above. The excess diffraction loss Ld is computed by the standard Deygout method combined with a lognormal distribution of loss between 50% and 0 as follows: Ld = Ld_50 – F i Ld_50 – Ld_ 0 Where, Ld_50 is Deygout diffraction loss computed with k = 1.4 Ld_ 0 is Deygout diffraction loss computed with k = 3 23 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 2: Microwave Propagation © 2016 Forsk. All Rights Reserved. F i is an interpolation factor based on an approximation of a log-normal distribution, l x , computed as described in Appendix 4 of the ITU452-11 Recommendation: l p 100 F i = -----------------------l 0 100 Point of incidence of anomalous propagation, 0 % , for the centre of the path is determined using, – 0,015 + 1,67 1 4 % for 70¬× 0 = 10 4,17 1 4 % for 70¬× where, : path centre latitude (degrees). The parameter 1 depends on the degree to which the path is above land (inland or coastal) and water. It is given by, 1 = 10 – d tm --------------------16 – 6,6 And, = 1 – e 0,2 + 10 – 0,496 + 0,354 5 – 4,12 10 –4 d 2,41 lm where 1 1 , Where, d tm : longest continuous land (inland coastal) section of the great-circle path (km) d lm : longest continuous inland section of the great-circle path (km). – 0,935 + 0,0176 Log 1 % for 70¬× and 4 = 10 0,3Log 1 % for 70¬× 10 Currently, Atoll uses the total length of the path for both d tm and d lm . 2.4.5 Atmospheric Loss Atmospheric loss, L a , is calculated as follows: La = 0 + w d Where, d is the length of the link (km) 0 is a specific attenuation due to dry air 2 –3 7,27 7,5 0 = ----------------------- + ------------------------------------- f 10 2 2 f + 0,351 f – 57 + 2,44 This formula is an approximate estimation of gaseous attenuation given by Rec ITU-R P.676-3 when f 57GHz , at sea level at a temperature of 15°C. In this formula, f is in GHz. w is a specific attenuation due to vapour. 3,79 + -----------------------------------------------2 f – 22,235 + 9,81 11,73 4,01 + --------------------------------------------------- + ------------------------------------------------------ –2 3,27 10 2 –4 w = f 10 –3 + 1,67 10 –4 + 7,7 10 f 2 f – 183,31 + 11,85 24 0,5 2 f – 325,153 + 10,44 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 2: Microwave Propagation AT332_TRM_E0 This formula is an approximate estimation of gaseous attenuation given by Rec ITU-R P.676-3 for f 350GHz , at sea level at a temperature of 15°C. In this formula, f is in GHz. 3 is the water-vapour density g m set by the user in the geoclimatic properties of the link being analysed. 2.4.6 Tropospheric Scatter Loss Five methods can be used to calculate tropospheric scatter loss ( L bs ): • • • • • ITU-R P.617-1 (50%) ITU-R P.617-1 (90%) ITU-R P.617-1 (99.9%) ITU-R P.452 (50%) Simplified Method 2.4.6.1 ITU-R P.617-1 L bs (dB) is calculated as follows: L bs = M + 30 log f + 10 log d + 30 log + L N + L c – G Tx – G Rx – Y q Where, M is a meteorologic parameter depending on climate f is the frequency (MHz) d is the distance between the transmitter and the receiver sites (Km) is the path angular distance (mrad) L N = 20 log 5 + H + 4,34 h is a meteorologic parameter depending on climate –3 d - (km) H = 10 ------------------------4 –6 2 k a - (km) h = 10 ---------------------------------8 a is the earth radius (6370 Km) k is the factor k (4/3) L c is the decoupling loss (dB) L c = G Tx + G Rx – L ant G Tx is the transmitter antenna gain (dB) G Rx is the receiver antenna gain (dB) Y q is the conversion factor for non excess percents different from 50% (dB) q is the percentage of time for which particular values of tropospheric scatter loss are not exceeded. Climate M (dB) 0- Polar Dry 33.2 0.27 0 – 2,2 – 8,1 – 2,3 10 –4 f e – 0,137h 2,9 Y 90 1- Polar Moderate 29.73 0.27 0 – 2,2 – 8,1 – 2,3 10 –4 f e – 0,137h 2,9 Y 90 2- Cold Dry 33.2 0.27 0 – 2,2 – 8,1 – 2,3 10 –4 f e – 0,137h 2,9 Y 90 3- Cold Moderate 29.73 0.27 0 – 2,2 – 8,1 – 2,3 10 –4 f e – 0,137h 2,9 Y 90 ( Km –1 ) Y(50) Y(90) Y(99.99) 25 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 2: Microwave Propagation © 2016 Forsk. All Rights Reserved. Climate M (dB) 4- Temperate Maritime 26 0.27 0 5- Temperate Continental Dry 33.2 0.27 0 – 2,2 – 8,1 – 2,3 10 –4 f e – 0,137h 2,9 Y 90 6- Temperate Continental Moderate 33.2 0.27 0 – 2,2 – 8,1 – 2,3 10 –4 f e – 0,137h 2,9 Y 90 7- Temperate Continental Wet 33.2 0.27 0 Graph 3 2,9 Y 90 8- Subtropical Wet 19.3 0.32 0 Graph 2 2,9 Y 90 9- Subtropical Arid 38.5 0.27 0 Graph 3 2,9 Y 90 10- Tropical Moderate 19.3 0.32 0 Graph 2 2,9 Y 90 11- Tropical 39.6 0.33 0 Graph 1 2,9 Y 90 ( Km –1 ) Y(50) Y(90) – 9,5 – 3e Y(99.99) – 0,137h 2,9 Y 90 ds Graph 1 Graph 2 Graph 3 <100 0 0 0 100 -8 -11 -12.5 200 -7 -13 -10 300 -5.3 -11.5 -7.8 400 -4.5 -9 -6 500 -4 -8.7 -4.5 600 -3.9 -8.5 -4 700 -3.6 -8.5 -4 800 -3.5 -8.5 -4 >=900 -3.4 -8.5 -4 ak Where ds is the effective distance in Km, ds = ----------------1000 2.4.6.2 ITU-R P. 452 L bs (dB) is calculated as follows: L bs = 190 + L f + 20 log d + 0,573 – 0,15N 0 + L c + L a Where, L f is loss depending on the frequency: L f = 25 log f – 2,5 log f 2 2 f is the frequency in MHz d is the distance between the transmitter and the receiver sites (Km) is the angular distance between the ray from the transmitter to its horizon and the ray from the receiver to its horizon (mrad) N 0 is the average refractivity extrapolated to sea level (N-Units) L c is the decoupling loss (dB) L c = G Tx + G Rx – L ant G Tx is the transmitter antenna gain (dB) G Rx is the receiver antenna gain (dB) L ant is the total attenuation (Tx and Rx) which takes into account the direction of the two antennas, the polarization of the transmitter and the polarization of the receiver (dB). 26 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 2: Microwave Propagation AT332_TRM_E0 L a is the gaseous absorption loss (dB) For further information on calculating L a , see "Atmospheric Loss" on page 24. 2.4.6.3 Simplified Method L bs (dB) is calculated as follows: L bs = 30 log f – 20 log d + F d N s Where, f is the frequency in MHz d is the distance between the transmitter and the receiver sites (Km) F d N s = F d – 0,1 N s – 301 e – d --------40 is the angular distance between the ray from the transmitter to its horizon and the ray from the receiver to its horizon (radian). If 0,01 d 10 , F d = 135,82 + 0,33 d + 30 log d If 10 d 70 , F d = 129,5 + 0,212 d + 37,5 log d If 70 d , F d = 119,2 + 0,157 d + 45 log d – 0,1057h T – 0,1057h R 1 N s = --- N 0 e +e 2 N 0 is the average refractivity extrapolated to sea level (N-Units) h T is the transmitter site height (Km) h R is the receiver site height (Km) 27 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 2: Microwave Propagation 28 © 2016 Forsk. All Rights Reserved. Chapter 3 Microwave Link Networks This chapter covers the following topics: • "Link Budget and Interference Analysis" on page 31 • "Performance Analysis" on page 35 • "Propagation in Rain Analysis" on page 36 • "Propagation in Clear-Air Analysis" on page 41 • "Surface Reflection Analysis" on page 70 Atoll 3.3.2 Technical Reference Guide for Microwave Networks ©2016 Forsk. All Rights Reserved 30 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 3 Microwave Link Networks In Atoll, any link Li can be studied from either: • Site A to Site B or • Site B to Site A Each direction of link can have its own parameters. 3.1 Link Budget and Interference Analysis 3.1.1 Input Name Value Unit Description Pmax L i Equipment parameter dBm Transmitter output power at the transmitter antenna port on link Li P_Tuning L i Link parameter dB Transmitter output power reduction used to calculate the transmitter nominal power on link Li P_Atpc L i Link parameter dB Transmitter nominal power reduction used to calculate the transmitter coordinated power on link Li S L i ,BER Equipment parameter dBm Receiver sensitivity level for a BER (Bit Error Rate) O L i ,BER Equipment parameter dBm Receiver overflow level for a BER (Bit Error Rate) G Tx L i Antenna parameter dBi Transmitter antenna gain on link Li G Rx L i Antenna parameter dBi Receiver antenna gain on link Li L_Model L i Calculated dB Propagation loss on link Li L_Ant L i Calculated dB Receiver antenna discrimination loss due to elevation and tilt misalignment on link Li L_Filter Tx L i Equipment parameter dB Transmitter filter loss on link Li L_Filter Rx L i Equipment parameter dB Receiver filter loss on link Li L_Circulator Tx L i Equipment parameter dB Transmitter circulator loss on link Li L_Circulator Rx L i Equipment parameter dB Receiver circulator loss on link Li L_Attenuator Tx L i Link parameter dB Transmitter attenuator loss on link Li L_Attenuator Rx L i Link parameter dB Receiver attenuator loss on link Li L_Connector Tx L i Link parameter dB Transmitter connector loss on link Li L_Connector Rx L i Link parameter dB Receiver connector loss on link Li L_Other Tx L i Link parameter dB Other transmitter losses on link Li L_Other Rx L i Link parameter dB Other receiver losses on link Li L_Shielding Tx L i Link parameter dB Transmitter shielding loss on link Li L_Shielding Rx L i Link parameter dB Receiver shielding loss on link Li 31 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks © 2016 Forsk. All Rights Reserved. Name Value Unit Description L_Feeder Tx L i Link parameter dB Transmitter feeder (cable or waveguide) loss on link Li L_Feeder Rx L i Link parameter dB Receiver feeder (cable or waveguide)loss on link Li Global parameter km2 Reference correlation area km2 Correlation area between link Li and link Lj L i L j L i L j L i L j ---------------- None Correlation area ratio between link Li and link Lj IRF L i L j Calculated dB Interference reduction factor on link Li from link Lj J/K Boltzmann’s constant 1,38 10 k – 23 T Li Link parameter Celsius Operating temperature in link Li B Tx L i Link parameter Hz Transmitter channel bandwidth on link Li NF Tx L i Equipment parameter dB Transmitter noise figure on link Li N0 Li 10 Log k + 10 Log 273 + T L i + 10 Log B s i + 30 dBm/Hz Thermal noise power level on link Li TD max Global parameter dB Maximum acceptable threshold degradation 3.1.2 Link Budget Calculation Details This part comprises all the calculation results that could be found on the report tab of the Microwave Analysis tool. 3.1.2.1 Nominal Power The power at which the transmitter is operating during normal propagation conditions on a link Li is expressed in dBm. Pnom L i = Pmax L i – P_Tuning L i The nominal power is used for EIRP L i calculation when the option "Power control on the useful signal" is not checked in the General tab of the Microwave Radio Links Properties. 3.1.2.2 Coordinated Power The power at which the transmitter is operating when Automatic Transmit Power Control (ATPC) is enabled on a link Li is expressed in dBm. Pcoord L i = Pnom L i – P_Atpc L i The coordinated power is used for EIRP L i calculation when the option "Power control on the useful signal" is checked in the General tab of the Microwave Radio Links Properties. The coordinated power is also used for interference calculation when the option "Power control" is set to "Depends on correlation" in the Interference tab of the Microwave Radio Links Properties. In that case, the value of P atpc s i will depend on L i L j : If L i L j 1 then P_Atpc L i = 0 . If L i L j 1 then P_Atpc L i = P atpc s i . 32 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 3.1.2.3 Transmission Attenuation The loss due to the use of feeders and related equipment by the transmitter on a link Li is expressed in dB. L_Att Tx L i = L_Feeder Tx L i + L_Connector Tx L i + L_Filter Tx L i + L_Circulator Tx L i + L_Attenuator Tx L i + L_Shielding Tx L i + L_Other Tx L i s i 3.1.2.4 EIRP (Equivalent Isotropic Radiated Power) The power actually radiated by the transmitter’s antenna on a link Li is expressed in dBm. Pnom L i + G L – L_Att L or EIRP L i = Tx i Tx i Pcoord L i 3.1.2.5 Reception Attenuation The loss due to the use of feeders and related equipment by the receiver on a link Li is expressed in dB. L_Att Rx L i = L_Feeder Rx L i + L_Connector Rx L i + L_Filter Rx L i + L_Circulator Rx L i + L_Attenuator Rx L i + L_Shielding Rx L i + L_Other Rx L i s i 3.1.2.6 Received Signal Level The signal strength at the receiver input on a link Li is expressed in dBm. RSL L i = EIRP L i – L_Model L i + G Tx L i + G Rx L i – L_Att Rx L i – L_Ant L i 3.1.2.7 Thermal Fade Margin The thermal fade margin used to compensate the fades, caused by the thermal noise, that results in an increase of the BER on a link Li is expressed in dB. TFM L i ,BER = RSL L i – S L i ,BER 3.1.2.8 Signal Enhancement Margin The signal enhancement margin used to compensate the enhancements, caused by the reinforcement of multipath signals, that results in an increase of the BER on a link Li is expressed in dB. SEM L i ,BER = O L i ,BER – RSL L i ,BER 3.1.3 Interference Calculation Details This part comprises all the calculation results that could be found while performing Interference analysis. 3.1.3.1 Single Interference Source This part considers the interference received from a single link. 3.1.3.1.1 Interference Signal Level The signal strength at the receiver input on a link Li from a link Lj is expressed in dBm. I Li ,L j = EIRP L j – L model L j + G Tx L j + G Rx L i – L_Att Rx L i – L_Ant L i – IRF L i L j 3.1.3.1.2 Carrier to Interference Ratio (C/I) The received signal level relative to an interference signal level from a link Lj on a link Li is expressed in dB. N L I L ,L 0 ii j - -----------------------------C --- L i ,L j = RSL L i – 10 log 10 10 + 10 10 I 3.1.3.1.3 Threshold Degradation The destructive interference effect on the receiver sensitivity on a link Li from a link Lj is expressed in dB. 33 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks © 2016 Forsk. All Rights Reserved. L I L ,L N--------------0 i i j ---------------- 10 10 10 + 10 - TD L i = 10 log -----------------------------------------N L 0 i --------------- 10 10 The interference signal level is considered to be disturbing the receiver and then unacceptable when TD L i TD max . 3.1.3.1.4 Effective Thermal Fade Margin The effective thermal fade margin on a link Li used to compensate the fades, caused by the thermal noise and the interference signal level from a link Lj, that result in an increase in the BER is expressed in dB. e TFM L i BER = RSL L i – S L i ,BER – TD L i 3.1.3.2 Multiple Interference Sources This part considers the interference received from many links. 3.1.3.2.1 Total Interference Signal Level in Clear Air Conditions The total signal strength at the receiver input on a link Li from n different links Lj is expressed in dBm. n n n n n n EIRP Lj – Lmodel Lj + G Lj + G Li – L_AttRx Li – L_Ant Li – IRF Li Lj I CA L i ,L j tot = j=1 3.1.3.2.2 n j=1 j=1 i=1 i=1 j=1 j=1 Total Interference Signal Level in Rain Conditions The total signal strength at the receiver input on a link Li from n different links Lj is expressed in dBm. n I R L i ,L j tot = + 10 log 3.1.3.2.3 n n n n n n EIRP Lj – Lmodel Lj + G Lj + G Li – L_AttRx Li – L_Ant Li – IRF Li Lj j=1 n j=1 j=1 i=1 i=1 j=1 j=1 L i L j Total Carrier to Interference Ratio (C/I) in Clear Air Conditions The received signal level relative to an interference signal level from multiple links Lj on a link Li is expressed in dB. N L I L ,L CA i j tot 0 i ---------------------------------------------- C 10 10 --- L i + 10 = RSL L i – 10 log 10 I CA tot 3.1.3.2.4 Total Carrier to Interference Ratio (C/I) in Rain Conditions The received signal level relative to an interference signal level from multiple links Lj on a link Li is expressed in dB. N L I L ,L R i j tot 0 i -------------- ---------------------------C 10 10 --- L i = RSL L i – 10 log 10 + 10 IR tot 3.1.3.2.5 Total Threshold Degradation in Clear Air Conditions The destructive interference effect on the receiver sensitivity on a link Li from multiple links Lj is expressed in dB. TD CA L i tot 3.1.3.2.6 I CA L i ,L j N--------------0 L i tot- ------------------------------ 10 10 10 + 10 = 10 log -----------------------------------------------------N0 Li -------------- 10 10 Total Threshold Degradation in Rain Conditions The destructive interference effect on the receiver sensitivity on a link Li from multiple link Lj is expressed in dB. 34 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 TD R L i tot 3.1.3.2.7 I L ,L L R i j tot N--------------0 i --------------------------- 10 10 10 + 10 - = 10 log --------------------------------------------------N L 0 i --------------- 10 10 Total Effective Thermal Fade Margin in Clear Air Conditions The effective thermal fade margin on a link Li used to compensate the fades, caused by the thermal noise and the interference signal level from multiple links Lj, that results in an increase of the BER is expressed in dB. eTFM CA L i ,BER tot = RSL L i – S L i ,BER – TD CA L i tot 3.1.3.2.8 Total Effective Thermal Fade Margin in Rain Conditions The effective thermal fade margin on a link Li used to compensate the fades, caused by the thermal noise and the interference signal level from multiple links Lj, that results in an increase of the BER is expressed in dB. eTFM R L i ,BER tot = RSL L i – S L i ,BER – TD R L i tot 3.2 Performance Analysis 3.2.1 Input Name Value Unit Description MTBF Tx L i Equipment parameter h Transmitter mean time between failures on link Li MTBF Rx L i Equipment parameter h Receiver mean time between failures on link Li HSB Tx L i Equipment parameter ms Transmitter hot stand-by commutaion delay on link Li HSB Rx L i Equipment parameter ms Receiver hot stand-by commutaion delay on link Li MTTR Li Link parameter h Mean time to repair on link Li 3.2.2 ITU-R P.530 Method 3.2.2.1 Total Outage Probability 3.2.2.1.1 Total Outage Probability in Rain Conditions The following formula is used: P t = Max P Rain P XPR 3.2.2.1.2 Total Outage Probability in Clear-Air Conditions Without Diversity The following formula is used: P t = P s + P ns + P se + P XP With Diversity The following formula is used: 3 3 --4- --- 3 --44 P t = P ds + P dns + P se + P XP 35 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks 3.2.2.1.3 © 2016 Forsk. All Rights Reserved. Total Outage Probability due to Equipment Reliability With Hot Stand-By The following formula is used: MTBF Rx L i MTBF Tx L i ---------------------------------------------------------P Eq_failure = 1 – ---------------------------------------------------------MTBF Tx L i + HSB Tx L i MTBF Rx L i + HSB Rx L i Without Hot Stand-By The following formula is used: P Eq_failure = MTTR L i MTTR L i ---------------------------------------------------------- + ---------------------------------------------------------MTTR L i + MTBF Tx L i MTTR L i + MTBF Rx L i MTTR L i MTTR L i - ---------------------------------------------------------- – --------------------------------------------------------- MTTR L i + MTBF Tx L i MTTR L i + MTBF Rx L i 3.2.2.2 Quality Performance Quality analysis is used to assess whether the total outage probability in clear-air conditions is greater than a required outage probability or not. The required outage probability is derived from ITU-T G.821, ITU-T G.826, or ITU-T G.828 recommendations. It can also be user-defined. 3.2.2.3 Availability Performance Quality analysis is used to assess whether the total outage probability in rain conditions is greater than a required outage probability or not. The required outage probability is derived from ITU-T G.821 or ITU-T G.826 recommendations. It can also be user-defined. 3.2.2.4 Global Annual Performance The global annual performance annual is an aggregated indicator that takes into account the quality performance and the availability performance of a link Li in both directions. Quality performances for each direction are considered being independent to each other, so the corresponding outage probabilities are added. Availability performance are considered being correlated, then the worst outage probability is used. Finally, quality performance and availability are considered being independent to each other, so the corresponding outage probabiilties are added. 3.3 Propagation in Rain Analysis 3.3.1 Input Name Value Unit Description R 0,01 L i Link parameter mm/h Rainfall rate exceeded for 0.01% of the average year on link Li Crane’s rainfall rate exceeded for p% of the average year on link Li. When 36 d L i 22,5 then a probability p Rp Li Calculated mm/h k Tx L i ,pol Calculated None Rain attenuation coefficient based on the used polarisation on link Li Tx L i ,pol Calculated None Rain attenuation coefficient based on the used polarisation on link Li d Li Calculated km Path length of link Li is used instead of p to determine the 22,5 rainfall rate where p = p -----------d Li Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 Name Value Unit Description C --- I 0_Tx L i Equipment parameter dB Transmitter carrier-to-interference ratio for a reference BER on link Li XPIF Tx L i Equipment parameter dB Transmitter cross-polarisation improvement factor on link Li f Tx L i Link parameter GHz Transmitter frequency on link Li 3.3.2 ITU-R P.530-5 3.3.2.1 Rain Fade Margin 3.3.2.1.1 Rain Coefficients k Tx L i ,pol and Tx L i ,pol are extracted from the ITU-R P.838 recommendation using logarithmic and linear regression. Atoll supports ITU-R P.838-1 and ITU-R P.838-3. The used method can be set in the Global parameters. 3.3.2.1.2 Rain Attenuation The rain attenuation for a specific frequency, rainfall rate and polarisation on link Li is expressed in dB/km. L i = k Tx L i ,pol R 0,01 L i 3.3.2.1.3 Tx L i ,pol Effective Path Length The effective path length that takes into account the nonuniformity of the rainfall along the path on link Li is expressed in km. 1 d eff L i = d L i -------------------------------------------------------------- with R 0,01 L i = Min R 0,01 L i 100 d Li 1 + --------------------------------------------------– 0,015 R 0,01 L i 35 e 3.3.2.1.4 Rain Fade Margin Exceeded for 0.01% of the Average Year The rain attenuation, excceeded for 0.01% of the average year, for a transmitter on link Li is expressed in dB. RFM 0,01 L i = L i d eff L i 3.3.2.1.5 Rain Fade Margin Exceeded for p% of the Average Year The rain attenuation, excceeded for p% of the average year, for a transmitter on link Li is expressed in dB. RFM p L i = RFM 0,01 L i 0,12 p 3.3.2.1.6 – 0,546 + 0,043 Log p with 0,001% p 1% Rain Fade Margin Exceeded for pw% of the Average Worst Month When the Average Worst Month pw% is Known It is necessary to convert pw% of the average worst month into p% of the average year because the rain attenuation formula only provides the rain fading margin on an average year basis. The corresponding average year statistics p for an average worst month statistics pw can be derived from the ITU-R P.841-3 recommendation. 1 – ---------------------- 1 – pw 1– - (%) where Q p = Q 1 p w We have p = ----------Qp 1,15 Atoll uses = 0,13 and Q 1 = 2,85 then we have: p = 0,3 p w . Finally the rain attenuation formula can be applied with the calculated average year probability p. The rain fade margin exceeded for p% of the average year will be exceeded for the corresponding pw of the average worst month. When the Average Year p% is Known It is necessary to convert p% of the average year of into pw% of the the average worst month. 37 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks We have p w © 2016 Forsk. All Rights Reserved. 12 – Q1 p = Q p p (%) where Q p = – Q1 3 – Log Q 1 3 -------------------------------------Log 0,3 – p Q 1 3 ---- 30 1 -- for Q p -----1- % 12 1 --- Q for -----1- p 3% 12 , where 1 Q p 12 for 3% p 30% for p 30% Atoll uses = 0,13 and Q 1 = 2,85 . The rain fade margin exceeded for p% of the average year will be exceeded for the corresponding pw of the average worst month. 3.3.2.2 Total Outage Probability due to Rain for the Average Year The following formula is used: p P Rain = --------100 Where p is the percentage of time for the average year where RFM p L i is exceeded found by solving the following equation: RFM p L i = RFM 0,01 L i 0,12 p – 0,546 + 0,043 Log p 3.3.3 ITU-R P.530-8, ITU-R P.530-10, ITU-R P.530-11, ITU-R P.530-12 and ITU-R P.530-13 3.3.3.1 Rain Fade Margin 3.3.3.1.1 Rain Coefficients k Tx L i ,pol and Tx L i ,pol are extracted from the ITU-R P.838 recommendation using logarithmic and linear regression. Atoll supports ITU-R P.838-1 and ITU-R P.838-3. The used method can be set in the Global parameters. 3.3.3.1.2 Rain Attenuation The rain attenuation for a specific frequency, rainfall rate and polarisation on link Li is expressed in dB/km. L i = k Tx L i ,pol R 0,01 L i 3.3.3.1.3 Tx L i ,pol Effective Path Length The effective path length that takes into account the nonuniformity of the rainfall along the path on link Li is expressed in km. 1 d eff L i = d L i -------------------------------------------------------------- where R 0,01 L i = Min R 0,01 L i 100 d Li 1 + --------------------------------------------------– 0,015 R0,01 L i 35 e 3.3.3.1.4 Rain Fade Margin Exceeded for 0.01% of the Average Year The rain attenuation, excceeded for 0.01% of the average year, for a transmitter on link Li is expressed in dB/km. RFM 0,01 L i = L i d eff L i 3.3.3.1.5 Rain Fade Margin Exceeded for p% of the Average Year The rain attenuation, excceeded for p% of the average year, for a transmitter on link Li is expressed in dB/km. For Links Located in Latitudes Equals to or Greater than 30° (North or South) RFM p L i = RFM 0,01 L i 0,12 p 38 – 0,546 + 0,043 Log p with 0,001 p 1 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 For Links Located in Latitudes Below 30° (North or South) RFM p L i = RFM 0,01 L i 0,07 p 3.3.3.1.6 – 0,855 + 0,139 Log p with 0,001 p 1 Rain Fade Margin Exceeded for pw% of the Average Worst Month When the Average Worst Month pw% is Known It is necessary to convert pw% of the average worst month into p% of the average year because the rain attenuation formula only provide the rain fading margin on an average year basis. The corresponding average year statistics p for an average worst month statistics pw can be derived from the ITU-R P.841-3 recommendation. 1 – ------------ -----------pw 1– 1– The conversion formula is p = ----------- (%) where Q p = Q 1 p w Q p 1,15 Atoll uses = 0,13 and Q 1 = 2,85 then we have: p = 0,3 p w . Finally the rain attenuation formula can be applied with the calculated average year probability p. The rain fade margin exceeded for p% of the average year will be exceeded for the corresponding pw of the average worst month. When the Average Year p% is Known It is necessary to convert p% of the average year of into pw% of the the average worst month. We have p w 12 – Q1 p = Q p p (%) where Q p = – Q1 3 – Log Q 1 3 -------------------------------------Log 0,3 – p Q 1 3 ----30 --1- for Q p -----1- % 12 1 -- Q for -----1- p 3% 12 , where 1 Q p 12 for 3% p 30% for p 30% Atoll uses = 0,13 and Q 1 = 2,85 . The rain fade margin exceeded for p% of the average year will be exceeded for the corresponding pw of the average worst month. 3.3.3.2 Outage Probability due to Rain for the Average Year The following formula is used: pP Rain = -------100 Where p is the percentage of time for the average year when RFM p L i is exceeded found by solving the following equation: RFM p L i = RFM 0,01 L i 0,12 p – 0,546 + 0,043 Log p for links located in latitudes equals to or greater than 30° (North or South) or RFM p L i = RFM 0,01 L i 0,07 p – 0,855 + 0,139 Log p for links located in latitudes below 30° (North or South) 3.3.3.3 Outage Probability due to XPD Reduction for the Average Year The following formula is used: P XPR = 10 n – 2 Where 39 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks © 2016 Forsk. All Rights Reserved. – 12,7 + 161,23 – 4 mn = ------------------------------------------------------------2 Where Ap - with m 40 , m = 23,26 Log ------------------------------------------- 0,12 RFM 0,01 L i Where A p the equivalent path attenuation is expressed in dB: C U – --- L + XPIF Tx L i I 0_Tx i -------------------------------------------------------------------------V with XPIC A p = 10 C U – --- Li I 0_Tx --------------------------------------- V without XPIC 10 Where 0,19 for 8 f Tx L i 20 U = 15 + 30 Log f Tx L i and V = 12,8 f Tx L i 22,6 for 20 fTx L i 35 3.3.4 Crane 3.3.4.1 Rain Fade Margin 3.3.4.1.1 Rain Coefficients k Tx L i ,pol and Tx L i ,pol are extracted from the ITU-R P.838 recommendation using logarithmic and linear regression. Atoll supports ITU-R P.838-1 and ITU-R P.838-3. The used method can be set in the Global parameters. 3.3.4.1.2 Rain Attenuation The rain attenuation for a specific frequency, rainfall rate and polarisation on link Li is expressed in dB/km. L i = k Tx L i ,pol R p L i 3.3.4.1.3 Tx L i ,pol Rain Fade Margin Exceeded for p% of the Average Year The rain attenuation, excceeded for p% of the average year, for a transmitter on link Li is expressed in dB/km. y Rp Li e – 1 s i ------------------------------------ for 0 d L i R p L i y RFM p s i = z d Li z Rp Li y Rp Li L ,pol B R p L i –e e – 1 ------------------------------------------------- s e----------------------------------- e Tx i -+ for R p L i d L i 22,5 i z y Where R p L i = 3,8 – 0,6 Ln R p L i B R p L i = 0,83 – 0,17 Ln R p L i z Tx L i ,pol = Tx L i ,pol c R p L i where c R p L i = 0,026 – 0,03 Ln R p L i B Rp Li y Tx L i ,pol = Tx L i ,pol u R p L i where u R p L i = ---------------------- + c Rp Li Rp Li 40 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 3.4 Propagation in Clear-Air Analysis 3.4.1 Input Name Value Unit Description PL Li Link Parameter % Percentage of time during which the refractivity gradient in the lowest 100 m of the atmosphere is less than or equal to -100 N-units/km on link Li H min L i Link Parameter m The lowest antenna above the sea level on link Li Lat Li Calculated m Latitude of the mid-point on link Li Lon L i Calculated m Longitude of the mid-point on link Li h Tx L i Calculated m Transmitter antenna height on link Li h Rx L i Calculated m Receiver antenna height on link Li h Tx_Avg L i Calculated m Transmitter antenna height above the average profile on link Li h Rx_Avg L i Calculated m Receiver antenna height above the average profile on link Li d Li Calculated km Path length of link Li f Tx L i Link Parameter GHz Transmitter frequency on link Li dN 1 L i Calculated N-unit/ km Point refractivity gradient in the lowest 65 m of the atmosphere not exceeded for 1% of an average year on link Li Sa Li Calculated m Standard deviation of terrain heights within a 110 km x 110 km area with a 30s resolution of link Li F Climate L i Link Parameter none Climate factor on link Li F Terrain L i Link Parameter or Calculated none Terrain factor on link Li Rg Li Calculated m Terrain roughness on link Li B 338 Microwave Radio Links Properties (Models tab) none Frequency exponent C 338 Microwave Radio Links Properties (Models tab) none Distance exponent W M_Tx L i Equipment parameter GHz Transmitter signature width in minimum-phase multipath case on link Li W NM_Tx L i Equipment parameter GHz Transmitter signature width in nonminimum-phase multipath case on link Li B M_Tx L i Equipment parameter GHz Transmitter signature depth in minimum-phase multipath case on link Li DFM L i ,BER Equipment parameter dB Dispersive fade margin for a value of BER, on link Li B NM_Tx L i Equipment parameter GHz Transmitter signature depth in nonminimum-phase multipath case on link Li 41 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks © 2016 Forsk. All Rights Reserved. Name Value Unit Description r_M Microwave Radio Links Properties (Models tab) ns Reference delay used to obtain the signature in minimum-phase multipath case r_NM Microwave Radio Links Properties (Models tab) ns Reference delay used to obtain the signature in non-minimum-phase multipath case K n_Tx L i Equipment parameter None Transmitter normalized signature parameter on link Li K n_M_Tx L i Equipment parameter None Transmitter normalized signature parameter on link Li K n_NM_Tx L i Equipment parameter None Transmitter normalized signature parameter on link Li Capacity Tx L i Equipment parameter None Transmitter capacity on link Li M Tx L i Equipment parameter None Transmitter modulation states on link Li GRateTx L i Equipment parameter bit/s Transmitter gross rate on link Li PRate Tx L i Equipment parameter bit/s Trasnmitter payload rate on link Li XPD g Calculated dB Read from the antenna cross-polar pattern at 0°. The smallest values between the transmitter’s one and the receiver’s one is used. C --- I 0_Tx L i Calculated dB Transmitter carrier-to-interference ratio for a reference BER on link Li XPIF Tx L i Equipment parameter dB Transmitter cross-polarisation improvement factor on link Li Tx L i Calculated m Transmitter wavelenghts on link Li Sep Rx L i Link Parameter m Receiver vertical antenna separation on link Li Sep_FreqTx L i Link Parameter m Transmitter frequency separation on link Li G Tx L i Antenna parameter dBi Transmitter antenna gain on link Li G Rx L i Antenna parameter dBi Receiver antenna gain on link Li 3.4.2 Fading 3.4.2.1 Frequency Non-Selective Fading 3.4.2.1.1 ITU-R P.530-5 - Method for Initial Planning Geoclimatic Parameters • Geoclimatic Factor The geoclimatic factor is calculated base on the location of the studied link: K = Where 42 10 10 10 10 – 6,5 – C Lat – C Lon – 7,1 – C Lat – C Lon – 5,9 – C Lat – C Lon – 5,5 – C Lat – C Lon PL Li 1,5 for overland links if H min L i 700m PL Li 1,5 for overland links if H min L i 700m PL Li 1,5 for medium-sized over-water links if PL Li 1,5 for large over-water links if strait or gulf sea Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 C Lat o o 0 for 53 S Lat L i 53 N Li o o o o = – 5,3 + Lat ---------------- for 53 N or 53 S Lat L i 60 N or 60 S 10 o o 0,7 for Lat L i 60 N or 60 S And C Lon 0,3 for 30 o W Lon L i 50 o E = o o – 0,3 for 150 W Lon L i 30 W 0 for others The month that has the highest value of P L L i should be chosen from the four seasonally representative months of February, May, August and November from maps given in ITU-R P.453 recommendation. An exception to this is that o o only maps for May and August should be used for latitudes greater than 60 N or 60 S . • Path Inclination The magnitude of the path inclination is expressed in milliradians: h Rx L i – h Tx L i p = ----------------------------------------d Li • Multipath Fading Occurrence Factor The multipath fading occurrence factor for the average worst month is expressed in percentage of time: P o = 100 K d L i 3,6 f Tx L i 0,89 1 + p – 1,4 Selection Process Between Method for Small Percentage of time and Method for Various Percentage of Time 1. Calculate the Percentage of Time pw_25dB for the Average Worst Month where 25 dB Fading Depth is Exceeded p w_25dB = P o 10 25 – ------ 10 2. Calculate the Percentage of Time pw_35dB for the Average Worst Month where 35 dB Fading Depth is Exceeded p w_35dB = P o 10 35 – ------ 10 3. Calculate the Criterion for Selection of Percentage of Time pw_25dB 25 – ----q a_25dB – 2 10 25- - – 4,3 10 q t_25dB = ---------------------------------------------------------------------------------+ ------- 25 800 – ------ 10 – 0,016 25 1 + 0,3 10 10 Where 100 – p w_25dB – 20 Log – Ln ------------------------------- 100 q a_25dB = ------------------------------------------------------------------------------25 4. Calculate the Criterion for Selection of Percentage of Time pw_35dB 35 – ----q a_35dB – 2 10 35- - – 4,3 10 q t_35dB = ---------------------------------------------------------------------------------+ ------- 35 800 – ------ 10 – 0,016 35 1 + 0,3 10 10 Where 43 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks © 2016 Forsk. All Rights Reserved. 100 – p w_35dB – 20 Log – Ln ------------------------------- 100 q a_35dB = ------------------------------------------------------------------------------35 5. Then the following decision tree is used: If q t_35dB 0 then q t = q t_25dB and 25 dB is the selection criterion. If TFM L i ,BER 25 dB then Atoll uses the method for small percentage of time If TFM L i ,BER 25 dB then Atoll uses the method for various percentage of time or If q t_35dB 0 then q t = q t_35dB and 35 dB is the selection criterion. If TFM L i ,BER 35 dB then Atoll uses the method for small percentage of time If TFM L i ,BER 35 dB then Atoll uses the method for various percentage of time Method for Small Percentage of Time Following is the percentage of time pw for the average worst month where TFM L i ,BER is exceeded: p w = P o 10 TFM L i ,BER – --------------------------------- 10 Method for Various Percentage of Time Following is the percentage of time pw for the average worst month where TFM L i ,BER is exceeded: q TFM L ,BER pw a i – ---------------------------------------------- 20 – 10 = 100 1 – e Where TFM L ,BER TFM L ,BER i i – ------------------------------- - – --------------------------------- – 0 016 TFM L i ,BER TFM L i ,BER 20 20 + ------------------------------q a = 1 + 0,3 10 10 q t + 4,3 10 800 Percentage of Time p for the Average Year Where TFM L i ,BER is Exceeded The following formula is used: p = p w 10 G – ------- 10 Where the geoclimatic conversion factor expressed in dB is: 0 7 o o 10,3 – 5 Log 1 + Cos 2 Lat L i – 2,8 Log d L i + 1,8 Log 1 + p for Lat L i 45 N or 45 S G = 10,3 – 5 Log 1 – Cos 2 Lat L 0 7 – 2,8 Log d L + 1,8 Log 1 + for Lat L 45 o N or 45 o S i i p i With G 10,8 dB . Outage Probability due to Frequency Non-Selective Fading for the Average Worst Month The following formula is used: pw P ns = -------100 44 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 3.4.2.1.2 ITU-R P.530-5 - Method for Detailed Planning Geoclimatic Parameters • Geoclimatic Factor The geoclimatic factor is calculated base on the location of the studied link: K = 10 – 5,4 – C Lat – C Lon 10 10 10 – 6 – C Lat – C Lon PL Li PL Li – 4,8 – C Lat – C Lon – 4,4 – C Lat – C Lon 1,5 1,5 for overland links if H min L i 700m for overland links if H min L i 700m PL Li 1,5 for medium-sized over-water links if PL Li 1,5 for large over-water links strait or gulf if sea Where C Lat o o 0 for 53 S Lat L i 53 N Li o o o o = – 5,3 + Lat ---------------- for 53 N or 53 S Lat L i 60 N or 60 S 10 o o 0,7 for Lat L i 60 N or 60 S And C Lon 0,3 for 30 o W Lon L i 50 o E = o o – 0,3 for 150 W Lon L i 30 W 0 for others The month that has the highest value of P L L i should be chosen from the four seasonally representative months of February, May, August and November from maps given in ITU-R P.453 recommendation. An exception to this is that o o only maps for May and August should be used for latitudes greater than 60 N or 60 S . • Path Inclination The magnitude of the path inclination is expressed in milliradians: h Rx L i – h Tx L i p = ----------------------------------------d Li • Antenna Height Above the Average Terrain Profile First the linear equation of the average profile is determined using the "method of least squares": AverageProfile x = a 0 x + a 1 Where xi hi N N N i=1 i=1 x i h i – ------------------------------hi – a0 xi N =1 =1 i=1 - and a 1 = i------------------------------------------a 0 = i-----------------------------------------------------------------2 N N x i N 2 i = 1 x i – -------------------N With: • x which corresponds to the distance along the path. Expressed in meters. • h which corresponds to the terrain height on a pixel. Expressed in meters. • N which corresponds to the number of extracted pixels along the path. 45 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks © 2016 Forsk. All Rights Reserved. Finally the transmitter and receiver antenna heights above the average terrain profile are calculated with the following formulas: h Tx_Avg L i = h Tx L i – AverageProfile 0 and h Rx_Avg L i = h Rx L i – AverageProfile d L i • Grazing Angle The grazing angle is expressed in milliradians: h Tx_Avg L i + h Rx_Avg L i - 1 – m 1 + b2 = --------------------------------------------------------d Li Where 1 c + 1- Cos 3 m 3 ------------b = 2 m ------------ --3- + 3 ArcCos 2 --------------------3- 3m m + 1 2 d Li m = ----------------------------------------------------------------------------------4 a e h Tx_Avg L i + h Rx_Avg L i with a e = 8500 h Tx_Avg L i – h Rx_Avg L i c = ----------------------------------------------------------h Tx_Avg L i + h Rx_Avg L i • Multipath Fading Occurrence Factor The multipath fading occurrence factor for the average worst month is expressed in percentage of time: P o = 100 K d L i 3,3 f Tx L i 0,93 1 + p – 1,1 – 1,2 Selection Process Between Method for Small Percentage of Time and Method for Various Percentage of Time 1. Calculate the Percentage of Time pw_25dB for the Average Worst Month where 25 dB Fading Depth is Exceeded p w_25dB = P o 10 25 – ------ 10 2. Calculate the Percentage of Time pw_35dB for the Average Worst Month where 35 dB Fading Depth is Exceeded p w_35dB = P o 10 35 – ------ 10 3. Calculate the Criterion for Selection of Percentage of Time pw_25dB 25 – ----q a_25dB – 2 10 25- - – 4 3 10 q t_25dB = ----------------------------------------------------------------------------------+ ------- 25 800 – ------ 10 – 0,016 25 1 + 0 3 10 10 Where 100 – p w_25dB – 20 Log – Ln ------------------------------- 100 q a_25dB = ------------------------------------------------------------------------------25 4. Calculate the Criterion for Selection of Percentage of Time pw_35dB 35 – ----q a_35dB – 2 10 35- - – 4 3 10 q t_35dB = ----------------------------------------------------------------------------------+ ------- 35 800 – ----- 10 – 0,016 35 1 + 0 3 10 10 Where 100 – p w_35dB – 20 Log – Ln ------------------------------- 100 q a_35dB = ------------------------------------------------------------------------------35 5. Then the following decision tree is used: 46 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 If q t_35dB 0 then q t = q t_25dB and 25 dB is the selection criterion. If TFM L i ,BER 25 dB then Atoll uses the method for small percentage of time If TFM L i ,BER 25 dB then Atoll uses the method for various percentage of time or If q t_35dB 0 then q t = q t_35dB and 35 dB is the selection criterion. If TFM L i ,BER 35 dB then Atoll uses the method for small percentage of time If TFM L i ,BER 35 dB then Atoll uses the method for various percentage of time Method for Small Percentage of Time Following is the percentage of time pw for the average worst month where TFM L i ,BER is exceeded: p w = P o 10 TFM L i ,BER – --------------------------------- 10 Method for Various Percentage of Time Following is the percentage of time pw for the average worst month where TFM L i ,BER is exceeded: q TFM L ,BER pw a i – ---------------------------------------------- 20 – 10 = 100 1 – e Where TFM L ,BER TFM L ,BER i i – ------------------------------- - – --------------------------------- – 0,016 TFM L i ,BER TFM L i ,BER 20 20 10 q t + 4,3 10 + ------------------------------- q a = 1 + 0,3 10 800 Percentage of Time p for the Average Year Where TFM L i ,BER is Exceeded The following formula is used: p = p w 10 G – ------- 10 Where the geoclimatic conversion factor expressed in dB is: 0 7 o o 10,3 – 5 Log 1 + Cos 2 Lat L i – 2,8 Log d L i + 1,8 Log 1 + p for Lat L i 45 N or 45 S G = 10,3 – 5 Log 1 – Cos 2 Lat L 0 7 – 2,8 Log d L + 1,8 Log 1 + for Lat L 45 o N or 45 o S i i p i With G 10,8 dB . Outage Probability due to Frequency Non-Selective Fading for the Average Worst Month The following formaul is used: pw P ns = -------100 3.4.2.1.3 ITU-R P.530-8 - Method for Initial Planning Geoclimatic Parameters • Geoclimatic Factor The geoclimatic factor is calculated base on the location of the studied link: 47 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks K = 5 10 –7 10 © 2016 Forsk. All Rights Reserved. – 0,1 C – C –C 0 Lat Lon PL Li 1,5 for inland links. 1 – r Log K + r Log K c i c cl if K cl K i for coastal links over/near large bodies of water. K = 10 if K cl K i Ki 1 – r c Log K i + r c Log K cm if K cm K i for coastal links over/near medium bodies of water. K = 10 if K cm K i Ki Where 1,7 if 0 H min L i 400m C 0 = 4,2 if 400 H min L i 700m H min L i 700m 8 if C Lat o o 0 for 53 S Lat L i 53 N = – 53 + Lat L for 53 o N or 53 o S Lat L 60 o N or 60 o S i i o o 7 for Lat L i 60 N or 60 S C Lon 3 for 30 o W Lon L i 50 o E = o o – 3 for 150 W Lon L i 30 W 0 for others K i = 5 10 –7 10 K cl = 2,3 10 K cm = 10 –4 – 0,1 C 0 – C Lat – C Lon 10 PL Li 1,5 – 0 1 C 0 – 0,011 Lat L i 0,5 Log K + Log K i cl The month that has the highest value of P L L i should be chosen from the four seasonally representative months of February, May, August and November from maps given in ITU-R P.453 recommendation. An exception to this is that o o only maps for May and August should be used for latitudes greater than 60 N or 60 S . • Path Inclination The magnitude of the path inclination is expressed in milliradians: h Rx L i – h Tx L i p = ----------------------------------------d Li • Multipath Fading Occurrence Factor The multipath fading occurrence factor for the average worst month is expressed in percentage of time: P o = 100 K d L i 3,6 f Tx L i 0,89 1 + p – 1,4 Selection Process Between Method for Small Percentage of Time and Method for Various Percentage of Time 1. Calculate the transition fading value between deep fading and shallow fading expressed in dB: A t = 25 + 1,2 Log P o 2. Then the following decision tree is used: If TFM L i ,BER A t then Atoll uses the method for small percentage of time 48 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 If TFM L i ,BER A t then Atoll uses the method for various percentage of time Method for Small Percentage of Time Following is the percentage of time pw for the average worst month where TFM L i ,BER is exceeded: p w = P o 10 TFM L i ,BER – --------------------------------- 10 Method for Various Percentage of Time Following is the percentage of time pw for the average worst month where TFM L i ,BER is exceeded: q TFM L ,BER pw a i – ---------------------------------------------- 20 – 10 = 100 1 – e Where TFM L ,BER TFM L ,BER i i – ------------------------------- - – --------------------------------- – 0,016 TFM L i ,BER TFM L i ,BER 20 20 q t + 4,3 10 + ------------------------------- q a = 2 + 1 + 0,3 10 10 800 Where A – -----t- qa – 2 At 20 – 4,3 10 + -------- q t = ---------------------------------------------------------------------------------800 At – ------ – 0,016 A t 20 1 + 0,3 10 10 Where 100 – p – 20 Log – Ln -------------------t 100 q a = -----------------------------------------------------------------At Where p t = P o 10 At – ------ 10 Percentage of Time p for the Average Year where TFM L i ,BER is Exceeded The following formula is used: p = p w 10 G – ------- 10 Where the geoclimatic conversion factor expressed in dB is: 0 7 o o 10,5 – 5,6 Log 1,1 + Cos 2 Lat L i – 2,7 Log d L i + 1,7 Log 1 + p for Lat L i 45 N or 45 S G = 10,5 – 5,6 Log 1,1 – Cos 2 Lat L 0 7 – 2,7 Log d L + 1,7 Log 1 + for Lat L 45 o N or 45 o S i i p i With G 10,8 dB . Outage Probability due to Frequency Non-Selective Fading for the Average Worst Month The following formula is used: pw P ns = -------100 49 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks 3.4.2.1.4 © 2016 Forsk. All Rights Reserved. ITU-R P.530-10, ITU-R P.530-11 and ITU-R P.530-12 - Method for Initial Planning Geoclimatic Parameters • Geoclimatic Factor The geoclimatic factor is calculated based on the location of the studied link: K = 10 • – 4,2 – 0,0029 dN 1 L i Path Inclination The magnitude of the path inclination is expressed in milliradians: h Rx L i – h Tx L i p = ----------------------------------------d Li • Multipath Fading Occurrence Factor The multipath fading occurrence factor for the average worst month is expressed in percentage of time: 3 P o = 100 K d L i 1 + p – 1,2 10 0,033 fTx L i – 0,001 H min L i Selection Process Between Method for Small Percentage of Time and Method for Various Percentage of Time 1. Calculate the transition fading value between deep fading and shallow fading expressed in dB: A t = 25 + 1,2 Log P o 2. Then the following decision tree is used: If TFM s i ,BER A t then Atoll uses the method for small percentage of time If TFM s i ,BER A t then Atoll uses the method for various percentage of time Method for Small Percentage of Time Following is the percentage of time pw for the average worst month where TFM L i ,BER is exceeded p w = P o 10 TFM L i ,BER – --------------------------------- 10 Method for Various Percentage of Time Following is the percentage of time pw for the average worst month where TFM L i ,BER is exceeded q TFM L ,BER pw a i – ---------------------------------------------- 20 – 10 = 100 1 – e Where TFM L ,BER TFM L ,BER i i – ------------------------------- - – --------------------------------- – 0,016 TFM L i ,BER TFM L i ,BER 20 20 10 q t + 4,3 10 + ------------------------------q a = 2 + 1 + 0,3 10 800 Where A – -----t- A qa – 2 20 t + -------q t = ---------------------------------------------------------------------------------– 4,3 10 800 A t- ----– – 0,016 A t 1 + 0,3 10 20 10 Where 50 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 100 – p – 20 Log – Ln -------------------t 100 q a = -----------------------------------------------------------------At Where p t = P o 10 A t – ------ 10 Percentage of Time p for the Average Year Where TFM L i ,BER is Exceeded The following formula is used: p = p w 10 G – ------- 10 Where the geoclimatic conversion factor expressed in dB is: 0 7 o o 10,5 – 5,6 Log 1,1 + Cos 2 Lat L i – 2,7 Log d L i + 1,7 Log 1 + p for Lat L i 45 N or 45 S G = 10,5 – 5,6 Log 1,1 – Cos 2 Lat L 0 7 – 2,7 Log d L + 1,7 Log 1 + for Lat L 45 o N or 45 o S i i p i With G 10,8 dB . Outage Probability due to Frequency Non-Selective Fading for the Average Worst Month The following formula is used: pw P ns = -------100 3.4.2.1.5 ITU-R P.530-10, ITU-R P.530-11 and ITU-R P.530-12 - Method for Detailed Planning Geoclimatic Parameters • Geoclimatic Factor The geoclimatic factor is calculated base on the location of the studied link: K = 10 • – 3,9 – 0,003 dN 1 L i Sa Li – 0,42 Path Inclination The magnitude of the path inclination is expressed in milliradians: h Rx L i – h Tx L i p = ----------------------------------------d Li • Multipath Fading Occurrence Factor The multipath fading occurrence factor for the average worst month is expressed in percentage of time: P o = 100 K d L i 3,2 1 + p – 0,97 10 0,032 f Tx L i – 0,00085 H min L i Selection Process Between Method for Small Percentage of Time and Method for Various Percentage of Time 1. Calculate the Transition Fading Depth Value between Deep Fading and Shallow Fading Expressed in dB: A t = 25 + 1,2 Log P o 2. Then the following decision tree is used: If TFM L i ,BER A t then Atoll uses the method for small percentage of time If TFM L i ,BER A t then Atoll uses the method for various percentage of time Method for Small Percentage of Time Following is the percentage of time pw for the average worst month where TFM L i ,BER is exceeded: 51 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks p w = P o 10 © 2016 Forsk. All Rights Reserved. TFM L ,BER i – --------------------------------- 10 Method for Various Percentage of Time Following is the percentage of time pw for the average worst month where TFM L i ,BER is exceeded: q TFM L ,BER pw a i – ---------------------------------------------- 20 – 10 = 100 1 – e Where TFM L ,BER TFM L ,BER i i – ------------------------------- - – --------------------------------- – 0,016 TFM L i ,BER TFM L i ,BER 20 20 q t + 4,3 10 + ------------------------------q a = 2 + 1 + 0,3 10 10 800 Where A – -----t- A qa – 2 20 t + -------q t = ---------------------------------------------------------------------------------– 4,3 10 800 A t- ----– – 0,016 A t 1 + 0,3 10 20 10 Where 100 – p – 20 Log – Ln -------------------t 100 q a = -----------------------------------------------------------------At Where p t = P o 10 At – ------ 10 Percentage of Time p for the Average Year Where TFM L i ,BER is Exceeded The following formula is used: p = p w 10 G – ------- 10 Where the geoclimatic conversion factor expressed in dB is: 0 7 o o 10,5 – 5,6 Log 1,1 + Cos 2 Lat L i – 2,7 Log d L i + 1,7 Log 1 + p for Lat L i 45 N or 45 S G = 10,5 – 5,6 Log 1,1 – Cos 2 Lat L 0 7 – 2,7 Log d L + 1,7 Log 1 + for Lat L 45 o N or 45 o S i i p i With G 10,8 dB . Outage Probability due to Frequency Non-Selective Fading for the Average Worst Month The following formula is used: pw P ns = -------100 3.4.2.1.6 ITU-R P.530-13 - Method for Initial Planning Geoclimatic Parameters • Geoclimatic Factor The geoclimatic factor is calculated based on the location of the studied link: 52 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 K = 10 • – 4,6 – 0,0027 dN 1 Path Inclination The magnitude of the path inclination is expressed in milliradians: h Rx L i – h Tx L i p = ----------------------------------------d Li • Multipath Fading Occurrence Factor The multipath fading occurrence factor for the average worst month is expressed in percentage of time: Po = K d Li 3 4 1 + p – 1,03 f Tx L i · 0 8 10 – 0,00076 H min L i Selection Process Between Method for Small Percentage of Time and Method for Various Percentage of Time 1. Calculate the transition fading value between deep fading and shallow fading expressed in dB: A t = 25 + 1,2 Log P o 2. Then the following decision tree is used: If TFM s i ,BER A t then Atoll uses the method for small percentage of time If TFM s i ,BER A t then Atoll uses the method for various percentage of time Method for Small Percentage of Time Following is the percentage of time pw for the average worst month where TFM L i ,BER is exceeded p w = P o 10 TFM L i ,BER – --------------------------------- 10 Method for Various Percentage of Time Following is the percentage of time pw for the average worst month where TFM L i ,BER is exceeded q TFM L ,BER pw a i – ---------------------------------------------- 20 – 10 = 100 1 – e Where TFM L ,BER TFM L ,BER i i – ------------------------------- - – --------------------------------- – 0,016 TFM L i ,BER TFM L i ,BER 20 20 + ------------------------------q a = 2 + 1 + 0,3 10 10 q t + 4,3 10 800 Where A – -----t- A qa – 2 20 t q t = ---------------------------------------------------------------------------------- – 4,3 10 + -------800 At – ------ – 0,016 A t 1 + 0,3 10 20 10 Where 100 – p t – 20 Log – Ln ------------------- 100 q a = -----------------------------------------------------------------At Where p t = P o 10 At – ------ 10 53 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks © 2016 Forsk. All Rights Reserved. Percentage of Time p for the Average Year Where TFM L i ,BER is Exceeded The following formula is used: p = p w 10 G – ------- 10 Where the geoclimatic conversion factor expressed in dB is: 0 7 o o 10,5 – 5,6 Log 1,1 + Cos 2 Lat L i – 2,7 Log d L i + 1,7 Log 1 + p for Lat L i 45 N or 45 S G = 10,5 – 5,6 Log 1,1 – Cos 2 Lat L 0 7 – 2,7 Log d L + 1,7 Log 1 + for Lat L 45 o N or 45 o S i i p i With G 10,8 dB . Outage Probability due to Frequency Non-Selective Fading for the Average Worst Month The following formula is used: pw P ns = -------100 3.4.2.1.7 ITU-R P.530-13 - Method for Detailed Planning Geoclimatic Parameters • Geoclimatic Factor The geoclimatic factor is calculated based on the location of the studied link: K = 10 • – 4 4 – 0,0027 dN1 L i 10 + S a L i – 0,46 Path Inclination The magnitude of the path inclination is expressed in milliradians: h Rx L i – h Tx L i p = ----------------------------------------d Li • Multipath Fading Occurrence Factor The multipath fading occurrence factor for the average worst month is expressed in percentage of time: Po = K d Li 3,1 1 + p – 1 29 f Tx L i 0 8 10 – 0,00089 H L min i Selection Process Between Method for Small Percentage of Time and Method for Various Percentage of Time 1. Calculate the Transition Fading Depth Value between Deep Fading and Shallow Fading Expressed in dB: A t = 25 + 1,2 Log P o 2. Then the following decision tree is used: If TFM L i ,BER A t then Atoll uses the method for small percentage of time If TFM L i ,BER A t then Atoll uses the method for various percentage of time Method for Small Percentage of Time Following is the percentage of time pw for the average worst month where TFM L i ,BER is exceeded: p w = P o 10 TFM L ,BER i – --------------------------------- 10 Method for Various Percentage of Time Following is the percentage of time pw for the average worst month where TFM L i ,BER is exceeded: 54 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 q TFM L ,BER pw a i – ---------------------------------------------- 20 – 10 = 100 1 – e Where TFM L ,BER TFM L ,BER i i – ------------------------------- - – --------------------------------- – 0,016 TFM L ,BER TFM L i ,BER 20 20 i q t + 4,3 10 + ------------------------------- q a = 2 + 1 + 0,3 10 10 800 Where A – -----t- qa – 2 At 20 – 4,3 10 + -------q t = --------------------------------------------------------------------------------- 800 At – ------ – 0,016 A t 20 1 + 0,3 10 10 Where 100 – p – 20 Log – Ln -------------------t 100 q a = -----------------------------------------------------------------At Where p t = P o 10 A t – ------ 10 Percentage of Time p for the Average Year Where TFM L i ,BER is Exceeded The following formula is used: p = p w 10 G – ------- 10 Where the geoclimatic conversion factor expressed in dB is: 0 7 o o 10,5 – 5,6 Log 1,1 + Cos 2 Lat L i – 2,7 Log d L i + 1,7 Log 1 + p for Lat L i 45 N or 45 S G = 10,5 – 5,6 Log 1,1 – Cos 2 Lat L 0 7 – 2,7 Log d L + 1,7 Log 1 + for Lat L 45 o N or 45 o S i i p i With G 10,8 dB . Outage Probability due to Frequency Non-Selective Fading for the Average Worst Month The following formula is used: pw P ns = -------100 3.4.2.2 Frequency Selective Fading 3.4.2.2.1 ITU-R P.530-8, ITU-R P.530-10 and ITU-R P.530-11 Method With the Equipment Signature The outage probability due to frequency selective fading for the average worst month is: B L B L M_Tx i NM_Tx i 2 2 – -------------------------– ----------------------------- m m 20 20 ----------- --------------P s = 2,15 W M_Tx L i 10 - + W NM_Tx L i 10 r_NM r_M Where is the multipath activity factor: 55 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks = 1–e – 0,2 P © 2016 Forsk. All Rights Reserved. 0,75 0 And m is the mean time delay: d L i 1,3 m = 0,7 ---------- 50 Method With the Normalized Equipment Signature The outage probability due to frequency selective fading for the average worst month is: m 2 P s = 2,16 K n_Tx L i 2 ----Ts Where T s is the equipment baud period expressed in ns: Log 2 M Tx L i T s = ---------------------------------BRate Tx L i Where BRateTx L i is the bit rate expressed in bits: BRate Tx L i = Capacity Tx L i PRate Tx L i or 30 BRate Tx L i = Capacity Tx L i GRate Tx L i ------ when PRateTx L i is not available. 32 3.4.2.2.2 ITU-R P.530-12 and ITU-R P.530-13 Method With the Equipment Signature The outage probability due to frequency selective fading for the average worst month is: B L B L M_Tx i NM_Tx i 2 2 – --------------------------– ------------------------------m m 20 20 P s = 2,15 W M_Tx L i 10 - + W NM_Tx L i 10 ----------- ---------------- r_NM r_M Where is the multipath activity factor: = 1–e 0,75 – 0,2 P 0 And m is the mean time delay: d L i m = 0,7 ----------50 1,3 Method With the Normalized Equipment Signature The outage probability due to frequency selective fading for the average worst month is: m 2 P s = 2,15 K n_M_Tx L i + K n_NM_Tx L i ---- Ts Where T s is the equipment baud period expressed in ns: Log 2 M Tx L i T s = ---------------------------------BRate Tx L i Where BRateTx L i is the bit rate expressed in bits: BRate Tx L i = Capacity Tx L i PRate Tx L i or 30 BRate Tx L i = Capacity Tx L i GRate Tx L i ------ when PRateTx L i is not available. 32 56 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 3.4.2.3 Vigants-Barnett 3.4.2.3.1 Method for Initial Planning Climatic Parameters • Climatic Factor The climatic factor can be user-defined or can depend on the climate where the studied link is located : 4 for hot/humid climate C = 1 for temperate climate 0,25 for dry climate • Multipath Fading Occurrence Factor The multipath fading occurrence factor for the average worst month is expressed in percentage of time: P o = 100 6 10 –7 C f Tx L i d L i 3 Method for Small Percentage of Time Following is the percentage of time pw for the average worst month where CFM L i ,BER is exceeded: p w = P o 10 CFM Li ,BER – --------------------------------- 10 Where CFM L i ,BER = 10 log 10 – T FM L i ,BER 10 + 10 – D FM L i ,BER 10 Percentage of Time p for the Average Year Where CFM L i ,BER is Exceeded 3 p = p w -----12 With the assumption that the ’worst month’ conditions occur during the three summer months (June, July and August). 3.4.2.3.2 Method for Detailed Planning Climatic Parameters • Climatic Factor The climatic factor depends on a climate factor and a terrain factor where the studied link is located: C = F Climate L i F Terrain L i Where • When terrain roughness is considered 2 for hot/humid climate F Climate L i = 1 for temperate climate 0,5 for dry climate And R g L i – 1,3 where 6 m R g L i 42 m F Climate L i = ------------ 15,2 • When terrain roughness is not considered 0,5 for hot/humid climate F Climate L i = 0,25 for temperate climate 0,125 for dry climate 57 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks © 2016 Forsk. All Rights Reserved. And 4 for hot/humid climate F Terrain L i = 1 for temperate climate 0,25 for dry climate • Multipath Fading Occurrence Factor The multipath fading occurrence factor for the average worst month is expressed in percentage of time: P o = 100 6 10 –7 C f Tx L i d L i 3 Method for Various Percentage of Time Following is the percentage of time pw for the average worst month where CFM L i ,BER is exceeded: p w = P o 10 CFM L i ,BER – --------------------------------- 10 Where CFM L i ,BER = 10 log 10 – T FM L i ,BER 10 + 10 – D FM L i ,BER 10 Percentage of Time p for the Average Year Where CFM L i ,BER is Exceeded 3 p = p w -----12 With the assumption that the ’worst month’ conditions occur during the three summer months (June, July and August). 3.4.2.4 CCIR Report 338 (KQ factor) 3.4.2.4.1 Method for Detailed Planning Climatic Parameters • Climatic Factor The climatic factor, KQ , is user-defined. It depends on the climate and the terrain where the studied link is located. • Multipath Fading Occurrence Factor The multipath fading occurrence factor for the average worst month is expressed in percentage of time: P o = 100 KQ f Tx L i B 338 d Li C 338 Method for Various Percentage of Time Following is the percentage of time pw for the average worst month where TFM L i ,BER is exceeded: p w = P o 10 TFM L ,BER i – --------------------------------- 10 Percentage of Time p for the Average Year Where TFM L i ,BER is Exceeded The following formula is used: p = p w 10 G – ------- 10 Where the geoclimatic conversion factor expressed in dB is: 0 7 o o 10,3 – 5 Log 1 + Cos 2 Lat L i – 2,8 Log d L i + 1,8 Log 1 + p for Lat L i 45 N or 45 S G = 10,3 – 5 Log 1 – Cos 2 Lat L 0 7 – 2,8 Log d L + 1,8 Log 1 + for Lat L 45 o N or 45 o S i i p i 58 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 With G 10,8 dB . Outage Probability due to Frequency Non-Selective Fading for the Average Worst Month The following formula is used: pw P ns = -------100 Recommended Values of Parameters KQ , B and C These empirical values are proposed by the CCIR 338 for six different locations: B 338 Japan 1,2 for 1 for NW Europe, USA and Northern Europe = UK 0,85 for 1,5 for ex-USSR C 338 3,5 for Japan,NW Europe and UK = 3 for USA and Northern Europe ex – USSR 2 for • For maritime temperate, Meditarranean, coastal or high humidity and temperate climatic regions 4 10 –3 - for USA ------------------1,3 KQ = S1 2 10 –3 for ex-USSR • For maritime sub-tropical climatic regions 10 –3 KQ = 3 -------------------- for USA 1,3 S1 • For continental temperate climates or mid-latitude inland climatic regions with average rolling terrain –7 1 10 –6 1,4 10 8,1 10 –5 4 10 –4 - to ------------------- ----------------------1,3 1,3 S2 S2 –3 KQ = 2,1 10 ---------------------- 1,3 S1 –4 4,1 10 –3 2,3 10 ---------------------- 1,3 S1 • for Japan for NW Europe for UK for USA for ex-USSR for Northern Europe For temperate climates, coastal regions with fairly flat terrain –6 9,9 10 ----------------------for Japan h1 + h2 KQ = 2,3 10 –3 to 4,9 10 – 3 for ex-USSR –3 10 6,5 ----------------------for Northern Europe 1,3 S1 • For high dry mountainous climatic regions 59 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks KQ = • 3,9 10 –8 for © 2016 Forsk. All Rights Reserved. Japan –3 1 10 -------------------- for 1,3 S1 1 10 –6 USA for Northern Europe For temperate climates, inland regions with fairly flat terrain 7,6 10 –3 to 2 10 –3 for ex-USSR –3 KQ = 3,3 10 -----------------------for Northern Europe 1,3 S1 Where h 1 and h 2 are the antenna heights expressed in meters. S 1 is the terrain roughness expressed in meters by the standard deviation of terrain elevations at 1 km intervals, with 6 m S 1 42 m . S 2 is the root mean square (r.m.s) value of the slopes expressed in millirad (mrad) measured between points separated by 1 km along the path excluding the first and the last complete interval, with 1 S 2 80 . 3.4.3 Signal Enhancement 3.4.3.1 ITU-R P.530-5 3.4.3.1.1 Thermal Fade Margin Exceeded for 0.01% of the Average Worst Month Method for Small Percentage of Time TFM L i ,BER 0,01_m is found by solving the following equation: p w = P o 10 TFM L i ,BER 0,01_m – ---------------------------------------------------- 10 Method for Various Percentage of Time TFM L i ,BER 0,01_m is found by solving the following equation: q TFM L ,BER pw i a 0,01_m – ----------------------------------------------------------------- 20 – 10 = 100 1 – e Where TFM L ,BER TFM L ,BER i i 0,01_m 0,01_m – -------------------------------------------------- - – ---------------------------------------------------- – 0,016 TFM L i ,BER 20 20 0,01_m q t + 4,3 10 + q a = 1 + 0,3 10 10 TFM L i ,BER 0,01_m ---------------------------------------------- 800 3.4.3.1.2 Thermal Fade Margin Exceeded for 0.01% of the Average Year Method for Small Percentage of Time TFM L i ,BER 0,01_y is found by solving the following equation: 60 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 0,01 -------------- = P o 10 10 TFM L ,BER i 0,01_y – -------------------------------------------------- 10 G – ------10 Where the geoclimatic conversion factor expressed in dB is: 0 7 o o 10,3 – 5 Log 1 + Cos 2 Lat L i – 2,8 Log d L i + 1,8 Log 1 + p for Lat L i 45 N or 45 S G = 10,3 – 5 Log 1 – Cos 2 Lat L 0 7 – 2,8 Log d L + 1,8 Log 1 + for Lat L 45 o N or 45 o S i i p i With G 10,8 dB . Method for Various Percentage of Time TFM L i ,BER 0,01_y is found by solving the following equation: q TFM L ,BER i a 0,01_y – --------------------------------------------------------------- 20 0,01- = 100 1 – e –10 ------------ – G ------ 10 10 Where TFM L ,BER TFM L ,BER i i 0,01_y 0,01_y- – ------------------------------------------------ – -------------------------------------------------- – 0,016 TFM L i ,BER 20 20 0,01_y + q a = 1 + 0,3 10 q t + 4,3 10 10 TFM L i ,BER 0,01_y ------------------------------------------- 800 Where the geoclimatic conversion factor expressed in dB is: 0 7 o o 10,3 – 5 Log 1 + Cos 2 Lat L i – 2,8 Log d L i + 1,8 Log 1 + p for Lat L i 45 N or 45 S G = 10,3 – 5 Log 1 – Cos 2 Lat L 0 7 – 2,8 Log d L + 1,8 Log 1 + for Lat L 45 o N or 45 o S i i p i With G 10,8 dB . 3.4.3.1.3 Selection Process Between Method for Small Percentage of Time and Method for Various Percentage of Time The transition fading value between deep fading and shallow fading is expressed in dB: SEM s i ,BER = 10 Then the decison is made based on the following options: If SEM s i ,BER SEM s i ,BER then Atoll uses the method for small percentage of time If SEM s i ,BER SEM s i ,BER then Atoll uses the method for various percentage of time 3.4.3.1.4 Method for Small Percentage of Time Percentage of Time pw for the Average Worst Month Where SEM L i ,BER is Exceeded p w = 100 – 10 – 1,7 + 0,2 TFM L i ,BER – SEM L i ,BER 0,01_m ---------------------------------------------------------------------------------------------------------------------------3,5 61 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks © 2016 Forsk. All Rights Reserved. Percentage of Time p for the Average Year where SEM L i ,BER is Exceeded p = p w 10 G – ------- 10 Where p w = 100 – 10 – 1,7 + 0,2 TFM L i ,BER – SEM L i ,BER 0,01_y ------------------------------------------------------------------------------------------------------------------------3,5 And the geoclimatic conversion factor expressed in dB is: 0 7 o o 10,3 – 5 Log 1 + Cos 2 Lat L i – 2,8 Log d L i + 1,8 Log 1 + p for Lat L i 45 N or 45 S G = 10,3 – 5 Log 1 – Cos 2 Lat L 0 7 – 2,8 Log d L + 1,8 Log 1 + for Lat L 45 o N or 45 o S i i p i With G 10,8 dB . Outage Probability due to Signal Enhancement for the Average Worst Month The following formula is used: pw P se = -------100 3.4.3.1.5 Method for Various Percentage of Time Percentage of Time pw for the Average Worst Month Where SEM L i ,BER is Exceeded q SEM L ,BER pw e i – --------------------------------------------- 20 – 10 = 100 – 58,21 1 – e Where SEM L ,BER 0,7 S EM L ,BER SEM L ,BER i i i – ------------------------------- - – --------------------------------- – ----------------------------------------------- SEM L i ,BER 20 20 20 10 q s + 12 10 + ------------------------------- q e = 8 + 1 + 0,3 10 800 Where q s = 2,05 q e – 20,3 Where 100 – p w – 20 q e = ---------------------------------- Log – Ln 1 – --------------------- SEM s i ,BER 58,21 Where p w = 100 – 10 – 1,7 + 0,2 TFM s i ,BER – SEM s i ,BER 0,01_m ----------------------------------------------------------------------------------------------------------------------------3,5 Percentage of Time p for the Average Year where SEM L i ,BER is Exceeded The following formula is used: p = p w 10 G – ------- 10 Where q SEM L ,BER pw 62 e i – --------------------------------------------- 20 – 10 = 100 – 58,21 1 – e Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 Where SEM L ,BER 0,7 S EM L ,BER SEM L ,BER i i i – ------------------------------- - – --------------------------------- – ----------------------------------------------- SEM L i ,BER 20 20 20 q s + 12 10 + ------------------------------- q e = 8 + 1 + 0,3 10 10 800 Where q s = 2,05 q e – 20,3 Where 100 – p w – 20 q e = ---------------------------------- Log – Ln 1 – --------------------- SEM L i ,BER 58,21 Where p w = 100 – 10 – 1,7 + 0,2 TFM L i ,BER – SEM L i ,BER 0,01_y ---------------------------------------------------------------------------------------------------------------------------3,5 And the geoclimatic conversion factor expressed in dB is: 0 7 o o 10,3 – 5 Log 1 + Cos 2 Lat L i – 2,8 Log d L i + 1,8 Log 1 + p for Lat L i 45 N or 45 S G = 10,3 – 5 Log 1 – Cos 2 Lat L 0 7 – 2,8 Log d L + 1,8 Log 1 + for Lat L 45 o N or 45 o S i i p i With G 10,8 dB . Outage Probability due to Signal Enhancement for the Average Worst Month The following formula is used: pw P se = -------100 3.4.3.2 ITU-R P.530-8, ITU-R P.530-10, ITU-R P.530-11, ITU-R P.530-12 and ITU-R P.530-13 3.4.3.2.1 Thermal Fade Margin Exceeded for 0.01% of the Average Worst Month Method for Small Percentage of Time TFM L i ,BER 0,01_m is found by solving the following equation: p w = P o 10 TFM L ,BER i – --------------------------------- 10 Method for Various Percentage of Time TFM L i ,BER 0,01_m is found by solving the following equation: q TFM L ,BER pw a i – ---------------------------------------------- 20 – 10 = 100 1 – e Where – TFM L ,BER – TFM L ,BER i i --------------------------------------- ----------------------------------------- – 0 016 TFM L i ,BER TFM L i ,BER 20 20 10 + ------------------------------q a = 1 + 0,3 10 q t + 4,3 10 800 63 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks 3.4.3.2.2 © 2016 Forsk. All Rights Reserved. Thermal Fade Margin Exceeded for 0.01% of the Average Year Method for Small Percentage of Time TFM L i ,BER 0,01_y is found by solving the following equation: 0,01- = P 10 ------------o 10 TFM L ,BER i 0,01_y – -------------------------------------------------- 10 G – ------10 Where the geoclimatic conversion factor expressed in dB is: 0 7 o o 10,5 – 5,6 Log 1,1 + Cos 2 Lat L i – 2,7 Log d L i + 1,7 Log 1 + p for Lat L i 45 N or 45 S G = 10,5 – 5,6 Log 1,1 – Cos 2 Lat L 0 7 – 2,7 Log d L + 1,7 Log 1 + for Lat L 45 o N or 45 o S i i p i With G 10,8 dB . Method for Various Percentage of Time TFM L i ,BER 0,01_y is found by solving the following equation: q TFM L ,BER i a 0,01_y – --------------------------------------------------------------- 20 – 10 0,01 ------------= 100 1 – e G – ------ 10 10 Where TFM L ,BER TFM L ,BER i i 0,01_y 0,01_y- – ------------------------------------------------ – -------------------------------------------------- – 0,016 TFM L ,BER 20 20 i 0,01_y + q a = 1 + 0,3 10 q t + 4,3 10 10 TFM L i ,BER 0,01_y -------------------------------------------- 800 And the geoclimatic conversion factor expressed in dB is: 0 7 o o 10,5 – 5,6 Log 1,1 + Cos 2 Lat L i – 2,7 Log d L i + 1,7 Log 1 + p for Lat L i 45 N or 45 S G = 10,5 – 5,6 Log 1,1 – Cos 2 Lat L 0 7 – 2,7 Log d L + 1,7 Log 1 + for Lat L 45 o N or 45 o S i i p i With G 10,8 dB . 3.4.3.2.3 Selection Process Between Method for Small Percentage of Time and Method for Various Percentage of Time The transition fading value between deep fading and shallow fading is expressed in dB: SEM s i ,BER = 10 Then the decison is made based on the following options: If SEM s i ,BER SEM s i ,BER then Atoll uses the method for small percentage of time If SEM s i ,BER SEM s i ,BER then Atoll uses the method for various percentage of time 3.4.3.2.4 Method for Small Percentage of Time Percentage of Time pw for the Average Worst Month Where SEM L i ,BER is Exceeded The following formula is used: 64 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 p w = 100 – 10 – 1,7 + 0,2 TFM L ,BER – SEM L ,BER i i 0,01_m --------------------------------------------------------------------------------------------------------------------------3,5 Percentage of Time p for the Average Year Where SEM L i ,BER is Exceeded The following formula is used: p = p w 10 G – ------- 10 Where p = 100 – 10 – 1,7 + 0,2 TFM L i ,BER – SEM L i ,BER 0,01_y ------------------------------------------------------------------------------------------------------------------------3,5 And the geoclimatic conversion factor expressed in dB is: 0 7 o o 10,5 – 5,6 Log 1,1 + Cos 2 Lat L i – 2,7 Log d L i + 1,7 Log 1 + p for Lat L i 45 N or 45 S G = 10,5 – 5,6 Log 1,1 – Cos 2 Lat L 0 7 – 2,7 Log d L + 1,7 Log 1 + for Lat L 45 o N or 45 o S i i p i With G 10,8 dB Outage Probability due to Signal Enhancement for the Average Worst Month pw P se = -------100 3.4.3.2.5 Method for Various Percentage of Time Percentage of Time pw for the Average Worst Month Where SEM L i ,BER is Exceeded The following formula is used: – q SEM L ,BER pw e i ------------------------------------------------------ 20 – 10 = 100 – 58,21 1 – e Where SEM L ,BER SEM L ,BER SEM L ,BER i i i – ------------------------------- - – --------------------------------- – 0,7 --------------------------------- SEM L i ,BER 20 20 20 q s + 12 10 + ------------------------------- q e = 8 + 1 + 0,3 10 10 800 Where q s = 2,05 q e – 20,3 Where 100 – p w – 20 q e = ---------------------------------- Log – Ln 1 – --------------------- SEM s i ,BER 58,21 Where p w = 100 – 10 – 1,7 + 0,2 TFM L i ,BER – SEM L i ,BER 0,01_m -----------------------------------------------------------------------------------------------------------------------------3,5 Percentage of Time p for the Average Year Where SEM L i ,BER is Exceeded The following formula is used: p = p w 10 G – ------- 10 Where 65 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks © 2016 Forsk. All Rights Reserved. – q SEM L ,BER pw e i ------------------------------------------------------ 20 – 10 = 100 – 58,21 1 – e Where SEM L ,BER SEM L ,BER SEM L ,BER i i i – ------------------------------- - – 0,7 --------------------------------- – --------------------------------- SEM L i ,BER 20 20 20 q s + 12 10 + ------------------------------- q e = 8 + 1 + 0,3 10 10 800 Where q s = 2,05 q e – 20,3 Where 100 – p w – 20 q e = ---------------------------------- Log – Ln 1 – --------------------- SEM L i ,BER 58,21 Where p w = 100 – 10 – 1,7 + 0,2 TFM L i ,BER – SEM L i ,BER 0,01_y ---------------------------------------------------------------------------------------------------------------------------3,5 And the geoclimatic conversion factor expressed in dB is: 0 7 o o 10,5 – 5,6 Log 1,1 + Cos 2 Lat L i – 2,7 Log d L i + 1,7 Log 1 + p for Lat L i 45 N or 45 S G = 10,5 – 5,6 Log 1,1 – Cos 2 Lat L 0 7 – 2,7 Log d L + 1,7 Log 1 + for Lat L 45 o N or 45 o S i i p i With G 10,8 dB Outage Probability due to Signal Enhancement for the Average Worst Month The following formula is used: pw P se = -------100 3.4.4 XPD Reduction 3.4.4.1 ITU-R P.530-8, ITU-R P.530-10 and ITU-R P.530-11 3.4.4.1.1 Multipath Parameter Multipath Activity Factor The following formala is used: = 1–e 3.4.4.1.2 0,75 – 0,2 P 0 Cross-Polarisation Parameters Static XPD The static XPD during unfaded conditions is expressed in dB: XPD g + 5 for XPD g 35 XPD 0 = 40 for XPD g 35 66 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 XPD Improvement Factor The improvement factor that shows strong dependence on the slope of the cross-polarized antenna patterns in the vertical planeis expressed in dB: k XP Q = – 10 Log ----------------- P0 Where k XP = 0,7 for one transmit antenna Static Improved XPD The static improved XPD during unfaded conditions is expressed in dB: C = XPD 0 + Q 3.4.4.1.3 Outage Probability due to XPD Reduction for the Average Worst Month The following formula is used: P XP = P o 10 M XPD – ---------------- 10 Where M XPD C C – --- L without XPIC I 0_Tx i = C L i + XPIF Tx L i with XPIC C – --I- 0_Tx 3.4.5 Diversity 3.4.5.1 ITU-R P.530-8, ITU-R P.530-10, ITU-R P.530-11, ITU-R P.530-12 and ITU-R P.530-13 3.4.5.1.1 Space Diversity Optimum Antenna Separation • Non-Terrain Based Method The optimum antenna separation on the receiver is expressed in meters: 3 Tx L i d L i S Rx = ------------------------------------------8 h Tx L i • Terrain Based Method The optimum antenna separation on the transmitter is expressed in meters: m Tx - with m being an even number (e.g. m 1 3 5 7 9 ... ) S Tx = ----------------2 Where 150 d L i Tx = --------------------------------------------------------------2 d Rx f Tx L i h Rx – --------------------12,74 k The optimum antenna separation on the receiver is expressed in meters: m Rx with m being an even number (e.g. m 1 3 5 7 9 ... ) S Rx = -----------------2 Where 67 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks © 2016 Forsk. All Rights Reserved. 150 d L i Rx = -------------------------------------------------------------2 d Tx f Tx L i h Tx – --------------------- 12,74 k Space Diversity Improvement Factor I ns_s – 0,04 Sep Rx L i = 1 – e 0,87 f Tx L i – 0,12 d Li 0,48 Po – 1,04 TFM s i ,BER – G Tx L i – G Rx L i -------------------------------------------------------------------------------------- 10 10 Outage Probability due to Frequency Non-Selective Fading for the Average Worst Month The following formula is used: P ns P dns = --------I ns_s Outage Probability due to Frequency Selective Fading for the Average Worst Month The following formula is used: 2 P ns P ds = ------------------------------2 1 – k s_s Where is the multipath activity factor: = 1–e 0,75 – 0,2 P 0 And 0,8238 for r w 0,5 0,109 – 0,13 Log 1 – r w = 1 – 0,195 1 – r for 0,5 r w 0,9628 w 0,5136 1 – 0,3957 1 – r w for r w 0,9628 2 k s_s Where r w is the frequency selective correlation coefficient: 2,17 2 2 1 – 0,9746 1 – k ns_s for k ns_s 0,26 rw = 1 – 0,6921 1 – k 2 1,034 for k 2 0,26 ns_s ns_s 2 Where k ns_s is the frequency non-selective correlation coefficient: I ns_s P ns 2 k ns_s = 1 – ---------------------- 3.4.5.1.2 Frequency Diversity Optimum Frequency Separation • Terrain Based Method The optimum frequency separation on the transmitter is expressed in MHz: S Tx = m f Tx with m being an even number (e.g. m 1 3 5 7 9 ... ) Where 4 7,5 10 d L i f Tx = ----------------------------------------------------------------------------------------2 2 d Tx d Rx h – -------------------- Tx 12,74 k- h Rx – --------------------12,74 k 68 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 Frequency Diversity Improvement Factor TFM L ,BER i I ns_f --------------------------------Sep_Freq Tx L i 80 10 - 10 = --------------------------------- -----------------------------------f Tx L i f Tx L i d L i Where Sep_Freq Tx L i = Min Sep_Freq L i Tx 0,5 Outage Probability due to Frequency Non-Selective Fading for the Average Worst Month The following formula is used: P ns P dns = --------I ns_f Outage Probability due to Frequency Selective Fading for the Average Worst Month The following formula is used: 2 P ns P ds = ------------------------------2 1 – k s_f Where is the multipath activity factor: = 1–e – 0,2 P 0,75 0 And 2 k s_f 0,8238 for rw 0,5 0,109 – 0,13 Log 1 – r w = 1 – 0,195 1 – r for 0,5 r w 0,9628 w 0,5136 1 – 0,3957 1 – r w for r w 0,9628 Where r w is the frequency selective correlation coefficient: rw 2,17 2 2 1 – 0,9746 1 – k ns_f for k ns_f 0,26 = 1 – 0,6921 1 – k2 1,034 for k 2 0,26 ns_f ns_f 2 Where k ns_f is the frequency non-selective correlation coefficient: I ns_f P ns 2 k ns_f = 1 – --------------------- 3.4.5.1.3 Space and Frequency Diversity (Two Receivers) Space and Frequency Diversity Improvement Factor The space and frequency diversity improvement factor is the same as the space diversity improvement factor: I ns_sf – 0,04 Sep Rx L i = 1 – e 0,87 f Tx L i – 0,12 d Li 0,48 Po – 1,04 TFM L i ,BER – G Tx L i – G Rx L i -------------------------------------------------------------------------------------- 10 10 Outage Probability due to Frequency Non-Selective Fading for the Average Worst Month The following formula is used: P ns P dns = ---------I ns_sf 69 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks © 2016 Forsk. All Rights Reserved. Outage Probability due to Frequency Selective Fading for the Average Worst Month The following formula is used: 2 P ns P ds = --------------------------------2 1 – k s_sf Where is the multipath activity factor: = 1–e 0,75 – 0,2 P 0 And 2 k s_sf 0,8238 for r w 0,5 0,109 – 0,13 Log 1 – r w = 1 – 0,195 1 – r for 0,5 r w 0,9628 w 0,5136 1 – 0,3957 1 – r w for r w 0,9628 Where r w is the frequency selective correlation coefficient: 2,17 2 2 1 – 0,9746 1 – k ns_sf for k ns_sf 0,26 rw = 1 – 0,6921 1 – k 2 1,034 for k 2 ns_sf ns_sf 0,26 2 Where k ns_sf is the frequency non-selective correlation coefficient: 2 k ns_sf = k ns_s k ns_f 2 3.4.5.2 Vigants-Barnett 3.4.5.2.1 Space Diversity Space Diversity Improvement Factor The following formula is used: –3 2 A – G 10 10 f H 10 l ns = 1,2 -----------------------------------------------------------------------------------d Where: f is the frequency (GHz), d is the link length (km), H is the antenna separation (m), A is the margin, and G is the gain difference between the standard antenna and the diversity antenna. When calculating the space diversity improvement factor, the actual improvement factor is limited to approximately 200. 3.5 Surface Reflection Analysis 3.5.1 Input 70 Name Value Unit Description d Li Calculated km Path length of link Li h Tx L i Calculated m Transmitter antenna height on link Li h Rx L i Calculated m Receiver antenna height on link Li y Rx Site parameter m Receiver altitude of ground above sea level y Tx Site parameter m Transmitter altitude of ground above sea level y0 Calculated m Altitude of mid-point of reflection area above the sea level Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 Name Value Unit Description x0 Calculated km Distance of mid-point of reflection area from transmitter ya Calculated m Altitude of first point of reflection area above the sea level yb Calculated m Altitude of last point of reflection area above the sea level xa Calculated km Transmitter distance to the first point of reflection area xb Calculated km Transmitter distance to the last point of reflection area k Median Calculated none Median k factor k max User defined none Maximum k factor k min User defined none Minimum k factor ae Calculated km Effective earth radius f Tx L i Link Parameter GHz Transmitter frequency on link Li t_Tx Link Parameter degrees Transmitter antenna’s tilt angle on link Li t_Rx Link Parameter degrees Receiver antenna’s tilt angle on link Li 3.5.2 ITU-R P.530-10, ITU-R P.530-11, ITU-R P.530-12 and ITU-R P.530-13 3.5.2.1 Surface Reflection Point Location The following calculations are conducted on the studied reflection area. From the transmitter the location of the reflexion point is expressed in km: d Li 1 + b d Tx = ---------------------------------2 From the receiver the location of the reflexion point is expressed in km: d Li 1 – b d Rx = ---------------------------------2 Where 1 3c + 1- Cos 3 m - b = 2 m --------------- + --- ArcCos ----------- -------------------3 3 2 3 3m m + 1 Where 2 d Li - 10 3 with a e = 6375 k Median m = ---------------------------------------------4 a e h Tx + h Rx Where h Tx – h Rx c = --------------------h Tx + h Rx Where the antenna height of the transmitter above the reflection area is expressed in meters: 3 h Tx = h Tx L i + y Tx – y 0 + x 0 10 Tan v And the antenna height of the receiver above the reflection area is expressed in meters: 3 h Tx = h Rx L i + y Rx – y 0 + d L i – x 0 10 Tan v 71 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks © 2016 Forsk. All Rights Reserved. Where yb – ya Tan v = --------------xb – xa 3.5.2.2 Difference in Path Length Between Direct and Reflected Signals The difference in path length between direct and reflected signals is expressen in wavelengths: 2 2 2 f Tx L i d Tx d Rx –3 - h Rx – ------------------------------------- 10 = ------------------------ h Tx – ------------------------------------0,3 d L i 12,74 k Median 12,74 k Median This difference is calculated for k min that would produce min and for k max that would produce max . 3.5.2.3 Surface Reflection Coefficient = 2 Sin – – Cos --------------------------------------------------------- for Horizontal polarisation 2 Sin + – Cos 2 – Cos ----------------------------Sin – 2 --------------------------------------------------------- for Vertical polarisation 2 – Cos ----------------------------Sin + 2 Where is the grazing angle: h Tx + h Rx 2 = -------------------- 1 – m 1 + b d Li And is the complex permittivity of the surface: 18 = r – j---------------------f Tx L i Where r is the relative permittivity and is the conductivity. Both are interpolated data from the ITU-R P.527 recommendation’s curves. 3.5.2.4 Effective Surface Reflection Coefficient eff = D R s R r D is the divergence factor of the surface: D = 2 1 – m 1 + b ------------------------------------------------2 1 + m 1 + 3 b R s is the divergence factor of the surface: Rs = –2 4 f Tx L i h Tx h Rx 10 d L i 1 + -------------------------------------------------------------------- 3 d Li f Tx L i h Tx + h Rx 10 - x b – x a ----------------------------------------------------------------------------- with x = Max ----------------------------------------------------------------------------------------------------2 –2 3 f Tx L i h Tx + h Rx 10 3 h Tx h Rx d L i 1 + ------------------------------------------------------------------ 3 d L i 2 x –2 R r is the roughness factor of the surface: 2 Rr = 72 ----1+g 2 --------------------------------------------------------------2 4 g g 1 + 2,35 ----- 2 ----2 4 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks AT332_TRM_E0 40 f Tx L i h Sin Where g = ----------------------------------------------------------------------3 h is the standard deviation of the surface height along the reflection area: N 1 2 for Root Mean Square Method Zi -- N i=1 h = N 1 2 Zi – Z for Standard Deviation Method --- N i=1 RelativeHeight90 – RelativeHeight10 for Interferdecile Range Method N Z i = h i – AverageProfile x i , Where 1 Z = --- N Zi , RelativeHeight10 = RelativeHeights(Int(0.1 N and i=1 RelativeHeight90 = RelativeHeights(Int(0.9 N where RelativeHeights is a sorted liste of Z i . AverageProfile x is the linear equation of the average profile etermined using the "method of least squares": AverageProfile x = a 0 x + a 1 Where N xi hi – xi hi N N hi – a0 xi N =1 =1 i=1 a 0 = i------------------------------------------------------------------ and a 1 = i------------------------------------------2 N N x i N 2 i = 1 x i – -------------------N i------------------------------=1 i=1 - Where • x which corresponds to the distance along the path. Expressed in meters. • h which corresponds to the terrain height on a pixel. Expressed in meters. • N which corresponds to the number of extracted pixels along the path. 3.5.2.5 Thermal Fade Margin Attenuation The maximum possible thermal fade margin attenuation from interference between the direct and the reflected signals is expresses in dB: L A max L – -----d– -----s- 20 20 = – 20 Log 10 – 10 L s is the attenuation of reflected signals expressed in dB: L s = L a – 20 Log eff Where L a = AntLoss Tx Tx + t_Tx + AntLoss Rx Rx + t_Rx With the corresponding angle of arrival of the refelcted signal expressed in degrees: h Tx h Tx – h Rx h Rx h Rx – h Tx d Rx d Tx 180 180 –3 –3 Tx = --------- ------ – ------------------------------------- 10 and Tx = --------- ------– --------------------- – ------------------------------------- 10 d Tx – ------------------- d Li d Li 12,74 k Median d Rx 12,74 k Median AntLoss Tx x is antenna attenuation for angle on transmitter’s antenna pattern. AntLoss Rx x is antenna attenuation for angle on receiver’s antenna pattern. L d is the attenuation of the direct signal expressed in dB: L d = AntLoss Tx t_Tx – d + AntLoss Rx t_Rx – d 73 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks With the corresponding angle of arrival of the direct signal expressed in degrees: d = – 0,0045 d L i 1 --- – 3 --- k 4 3.5.2.6 Attenuation Graphs The plotted parameter on the attenuation graphs is expressed in dB: 2 = 10 Log 1 + eff – 2 eff Cos 2 Three graphs can be plotted by varying: • • • 74 The receiver’s antenna height The transmitter’s frequency The k factor © 2016 Forsk. All Rights Reserved. AT332_TRM_E0 Atoll 3.3.2 Technical Reference Guide for Microwave Networks Chapter 3: Microwave Link Networks 75 Atoll 3.3.2 Technical Reference Guidefor Microwave Networks © Forsk 2016 76 • Head Office 7 rue des Briquetiers 31700 Blagnac, France Tel: +33 562 747 210 Fax: +33 562 747 211 AT332_TRM_E0 • US Office • China Office 200 South Wacker Drive – Suite 3100 Chicago, IL 60606, USA Tel: +1 312 674 4800 Fax: +1 312 674 4847 Suite 302, 3/F, West Tower, Jiadu Commercial Building, No. 66 Jianzhong Road, Tianhe Hi-Tech Industrial Zone, Guangzhou, 510665, P. R. of China Tel: +86 20 8553 8938 Fax: +86 20 8553 8285 www.forsk.com October 2016