GPRS doc

(E)GPRS Network InfrastructureMS BSC MSC PSTN SS7 Network SGSN SGSN Nokia Security GW EIR SMS-GMSC BTS HLR/AuC CG DNS Nokia Security GW Router Router STM-1 Nokia IP650 sec GW Router LAN SWITC H LIG GGSN GPRS IP Backbone Network GGSN Router STM-1 Nokia IP650 sec GW Corporate 1 Intranet Router Nokia IP650 sec GW MODEM POOL FOR DIALUP Nokia Security GW Nokia Security GW MODEM POOL FOR DIALUP Internet Corporate 2 Intranet SGSN Company Confidential 1 © 2005 Nokia SGSN V1-Filename.ppt / yyyy-mm-dd / Initials ELECTRICAL ET Metro BSC GB LINK Hub GB LINK SGSN GGSN Company Confidential 2 © 2005 Nokia V1-Filename.ppt / yyyy-mm-dd / Initials . NSEI PLANNING NSEI 1 NSEI 2 NSEI 3 NSEI 4 Company Confidential 3 © 2005 Nokia V1-Filename.ppt / yyyy-mm-dd / Initials . Summary BTS • GPRS territory • BTS HW considerations (TRX & BB-card) • BTS SW (EPCR) MS/Client parameters • GPRS/EDGE capability and release •Multislot support RF BTS BSC Abis Gb 2G SGSN BSS HLR TC HLR/ AC/ EIR MSC/VLR SGSN • QoS profile • GPRS settings • PCU variant & dimensioning • PCU strategy in mixed configuration • BSS SW and features TCSM • Unit capacity (PAPU etc.Network Element and Configuration Audit .) • BSS Gb Flow control Gs IP/MPLS/IPoATM backbone Gn Gi Application Applicatio Servers n Servers (colocated Server • load • settings (Linux/Win) GGSN RF interface • Coverage •C/I • Capacity • Traffic volume • Mobility Gb interface Abis interface • EDAP size / dimensioning • # of E1/T1s • Bearer size • IP v. FR • Dimensioning • GPRS/EDGE traffic Company Confidential 4 © 2005 Nokia V1-Filename.s.ppt / yyyy-mm-dd / Initials . INPUT GIVEN FOR THE GPRS PLANNING • No. of time slot required for the GPRS territory : CDED=1 and CDEF=1 • No. Of sites planned per BSC : 100 • Access rate (CIR) is the speed required at the GB interface : 256 Kbps Company Confidential 5 © 2005 Nokia V1-Filename. of BTS per EDAP i. of sectors prevalent : 3 • No. of time slot used for EDAP on Abis (64 Kbps) : 3 Time slot • % of upgrade is the Teritory upgrade for the future perspective : 10 % • No.e the No.ppt / yyyy-mm-dd / Initials . OUTPUT REQUIRED • No. Of Gb Link required • No. Of BCSU required • No. of PCU or No. of sites per NSEI required • No. of E1 required from the BSC to Metro Hub Company Confidential 6 © 2005 Nokia V1-Filename. of NSEI required in BSC • No.ppt / yyyy-mm-dd / Initials . of PCU required : 6/2 = 3 • No.2 +1 (for future use) ~ 6 • 2 NSEI supports 1 BCSU so no.4 ~ 230 • So no.ppt / yyyy-mm-dd / Initials . so access rate can be given by 1 E1 = 1984/ access rate (256) = 1984 / 256 ~ 7 Company Confidential 7 © 2005 Nokia V1-Filename. of NSEI required is equivalent to the no. of time slot/sector * no of time slot used for EDAP :.How to calculate what • No.2 * 3 = 6 • So total time slots per site 6 + 6 = 12 • 1 NSEI support 256 time slot with upgrade % as 10 so total no of time slots which can be equipped is 256 . of sectors : 2 x 3 • No. of Gb link = 3 • On 1 E1 we can get 31x64 = 1984 .10% of 256 = 230.16 ~ 19 • So no NSEI required / BSC : 100 / 19 = 5. of sites per NSEI is 230/12 = 19. of EGPRS resources used in 1 sector * No. 2 kbit/s .4 kbit/s 59.4 kbit/s 29.8 kbit/s 17.8 kbit/s 54.ppt / yyyy-mm-dd / Initials Data rate Abis PCM allocation (fixed + pool) 8.6 kbit/s 44.2 kbit/s 14.8 kbit/s 11.Transmission requirement for EGPRS coding schemes in Abis interface Coding scheme MCS-1 MCS-2 MCS-3 MCS-4 MCS-5 MCS-6 MCS-7 MCS-8 MCS-9 Company Confidential 8 © 2005 Nokia V1-Filename.6 kbit/s 22. EDGE modulations Scheme Modulatio n 8PSK Maximum rate [kb/s] MCS-9 MCS-8 MCS-7 MCS-6 MCS-5 MCS-4 MCS-3 MCS-2 MCS-1 59.6 / 27.6 14.8 / 13.4 17.8 29.2 8.2 22.2 54.4 44.6 11.ppt / yyyy-mm-dd / Initials .8 GMSK Company Confidential 9 © 2005 Nokia V1-Filename. . • EDGE has nine modulation and coding schemes.9 use 8-PSK modulation • Operator can set the MCS to start with • E..9.4.GPRS & EGPRS coding schemes MCS-1 • GPRS has four coding schemes.. MCS-1.. number of octets CS-1 20 CS-2 30 CS-3 36 CS-4 50 MCS-6 74 MCS-7 56 MCS-8 68 MCS-9 74 74 68 56 Company Confidential 10 © 2005 Nokia V1-Filename. • MCS-1. All use GMSK. CS-1. MCS-5.4 use GMSK.. always start with MCS-9 22 MCS-2 28 MCS-3 37 MCS-4 44 MCS-5 56 RLC/MAC block (radio block) redundancy from channel coding RLC data block.g...ppt / yyyy-mm-dd / Initials .. C/I of EGPRS coding schemes in TU50iFH. and consequently higher peak throughput.EDGE link performance In RLC layer (kbit/TSL) • • • • GPRS with re-transmission with same coding scheme Retransmissions with EDGE can be sent with the new scheme •Bit Error Probability (BEP) is a new MS quality measurement introduced In general. without incremental redundancy. but it also tolerates less noise or interference. 40 MCS-1 MCS-2 MCS-3 MCS-4 MCS-5 MCS-6 MCS-7 MCS-8 MCS-9 30 20 10 0 0 Company Confidential 11 © 2005 Nokia V1-Filename. New parameters Ideal Link Adaptation 60 50 • Max BLER for Ack and Non-Ack modes • Can be used to tune to use more higher MCS’s • Mean BEP offset for GMSK and 8-PSK • Set threshold for MCS change • The figure shows throughput vs. a higher coding scheme has higher coding rate.ppt / yyyy-mm-dd / Initials 5 10 15 20 25 30 C/I . BUSY TCH = CS traffic trf_12b ave_busy_tch/ res_av_denom14 Free capacity AVG.GPRS: territory (S9-10) TRX 1 TRX 2 CCCH TS TS TS TS TS TS TS Circuit Switched Territory Packet Switched Territory The following are the operator configurable parameters for territory management:  GPRSenabled (BTS-level) GENA  GPRSenabledTRX (TRX-level)  DefaultGPRScapacity (BTS-level)  PreferBCCHfreqGPRS (BTS-level)  DedicatedGPRScapacity (BTS-level) TS TS TS TS TS TS TS TS The main principle is that GPRS (PS) uses the capacity that remains from the CS traffic.GPRS CH USED ach_1 Allocated resources Availability ava_1d AVG. TSL used for UL GPRS trf_78b AVG. AVAILABLE GPRS CHANNELS in PS territory ava_16 (S9) ave_GPRS_channels_sum/ave_GPRS_channels_den ADDIT. Rounded downwards. AVAILABLE DEDICATED GPRS CHANNELS ava_17 (S9) ave_GPRS_channels_sum/ave_GPRS_channels_den PEAK DEDICATED GPRS CHANNELS /c2066(S9) peak_permanent_gprs_ch Used capacity for speech UNAVAILABLE TCH c2040 AVG.ppt / yyyy-mm-dd / Initials Used resources . Additional GPRS Capacity Default GPRS Capacity Dedicated GPRS Capacity GTRX CDED CDEF BFG GTUGT Circ ui Territory border moves Dy n a m i c a l l y based on Circuit Switched traffic load t Sw itche by in not affecd capac ity trod ucin ted g GP RS  TerritoryUpdateGuardTimeGPRS (BSC-level) • Circuit Switched traffic has priority • In each cell Circuit Switched & Packet Switched territories are defined • Territories consist of consecutive timeslots CDEF CDED Used capacity for GPRS PEAK GPRS CHANNELS /c2063(S9) peak_gprs_channels AVG. Includes dedicated time slots. AVAILABLE TCH in CS territory ava_15 (S9) ave_avail_TCH_sum/ ave_avail_TCH_den AVG. Given as % over dual TCH tsls of GPRS enabled TRXs. TSL used for DL GPRS trf_79b Company Confidential 12 © 2005 Nokia V1-Filename. g PS Active EGPRS ch < EDAP resources) TRX 1 RTSL 0 1 CS-2 2 MCS-1 MCS-9 MCS-7 MCS-1 MCS-7 3 4 5 6 7 Requests PCM subTSL 1 2 3 4 PCM TSL 8 9 10 11 5 4 7 2 5 4 7 5 4 7 4 - - - CS-2 MCS-1 MCS-9 MCS-7 MCS-1 MCS-7 Grants Company Confidential 13 © 2005 Nokia V1-Filename.ppt / yyyy-mm-dd / Initials .DL Data Scheduling Example – “No need to share case” • There are enough EDAP resources to handle adequately all the TBFs and MCS requests. (e. g PS Active EGPRS ch > EDAP resources) TRX 1 RTSL 0 1 CS-2 MCS-5 MCS-9 MCS-8 MCS-1 MCS-7 2 3 4 5 6 7 Requests PCM TSL PCM subTSL 1 2 3 10 11 12 4 3 - 5 4 2 5 4 7 5 4 7 PCU-TRX 0 - - CS-2 MCS-5 MCS-7 MCS-7 MCS-1 MCS-6 Grants Company Confidential 14 © 2005 Nokia V1-Filename.DL Data Scheduling Example (sharing case) • Because EDAP is a shared resource between a higher number of EGPRS TSL it is possible to encounter the situation where there are not enough EDAP resources to handle “adequately” all the TBFs (e.ppt / yyyy-mm-dd / Initials . 7 • • Slave group utilization is 0.EDAP utilization •6 EGPRS RTSLs (Dedicated + Default territory) • 50 % utilization assumed (3 Data Erlangs traffic) • On average 3 RTSLs used TRX 1 TRX 2 TS TS BCCH PBCCH TS TS TS TS TS TS TS Dedicated EGPRS TSL Default territory EGPRS TSL TS TS TS TS TS TS TS TS TS RTSLs use MCS7 (44.8 kbit/s) with average C/I=13dB and throughput 30kbit/s • Effective data rate factor excluding retransmissions over the air-interface is 30/44.7*0.ppt / yyyy-mm-dd / Initials Company Confidential 15 © 2005 Nokia .35 V1-Filename.8 ~ 0.5= 0. ppt / yyyy-mm-dd / Initials PLAN B .PLAN A Company Confidential 16 © 2005 Nokia V1-Filename. SNO PLAN A PLAN B 1 Both Non BCCH and BCCH Trx can access the EDGE Facility If the BCCH TRX goes faulty then also the EDGE users can access the N/W since the 2nd TRX has been defined on the EDAP Pool Using this plan we can change the BFG priority depending on the Interference in the N/W In case of extending the time slot of EDGE in Non BCCH TRX also can be done if congestions is observed in the Site While expanding the N/W from the 222 to 332 configuration we need to Modify the EDAP pool Only BCCH TRX can access the EDGE facility 2 If BCCH TRX goes faulty then The EDGE Service can not be accessed since the 2nd TRX has not been defined on the EDAP POOL 3 We can not change the BFG unstill and unless the EDAP pool need to be redesigned 4 We can not extend the Non BCCH TRX time slot during the congestion since that TRX is not mapped on the EDAP Pool 5 Need not to modify the EDAP pool since only BCCH TRX is being mapped Company Confidential 17 © 2005 Nokia V1-Filename.ppt / yyyy-mm-dd / Initials . ppt / yyyy-mm-dd / Initials . of sites per NSEI depend on the EDAP pool size and no.Conclusion • The No. of time slot used for the GPRS territory • Beside if we need to extend the resourced at ABIS end we need to defince the EDAP pool • If we require the Speed at GB we need to go to higher CIR Company Confidential 18 © 2005 Nokia V1-Filename.