129142407 LTE Radio Procedures

May 30, 2018 | Author: Giovanny Fco Maldonado | Category: Radio, Telecommunications, Telecommunications Engineering, Wireless, Electronics
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Security Level: www.huawei.com LTE Radio Interface Procedures HUAWEI TECHNOLOGIES CO., LTD. Contents 1- FAQs Frame Structure//Throughput Calculations etc 2- Reselection 3- SIBs 3- Registration IDLE Mode 4-Paging 5-Handover 6-DL Power Connected Mode Control 7-DL Scheduling Self Optimization Network 8-ANR 9-ICIC HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 2 FAQs HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 3 Resource Element HUAWEI TECHNOLOGIES CO. LTD. No spread without permission.Frame Structure (FDD) Related Concept 1. Page 4 .Subcarrier 5.Radio Frame 2-Subframe 3-Slot 4.Resource Block (Scheduling Minimum Unit) 6. Channel BW (MHz) RB Number Subcarrier Number 1..4 6 72 3 15 180 5 25 300 10 50 600 15 75 900 20 100 1200 Huawei proprietary. e. Page 5 .Total Number of RE for PDCCH=100(RB for 100Mhz)*12(SC)*3 2. LTD.Number of Scheduled User in 1 TTI Scheduling information is in PDCCH frame. Huawei proprietary. 1. (1270-PCFICH-PHICH)/17 ~~ 1000 users approx HUAWEI TECHNOLOGIES CO.. No spread without permission.Total Number of bits for PDCCH in 1 TTI=100*12*3*Modulation 2bits for QPSK 4bits for 16QAM 6bits for 64QAM Based on CQI Take 6 as example: Total Number of bits for PDCCH in 1 TTI=100*12*3*6=21600 Number of bits required by each user for scheduling= 17 Total User support for scheuding =21600/17=1270 Users Note : Actually need to consider PCFICH+PHICH (from diagram) i. and consider the coding rate. 8 / (14 * 12) =8/168= 1/21. a downlink sub-frame occupies 8 subcarriers. RS symbol number=16. and the PDCCH symbol is the first symbol of the sub-frame.. LTD.Downlink Calculation Downlink maximum throughput = Number of RB × 12 (Number of Sub-carrier with one RB) × 14 (Number of Symbols with a Sub-frame) × [ 1 － (RS overhead and PDCCH overhead) ] × Modulation symbols efficiency × MIMO × 1000 (Number of Sub-frame in one second) × Coding rate Example: Calculate the FDD LTE system 10M. the Coding rate is 1.4Mbps this is an ideal value. this is the minimal overhead in PDCCH. so the minimal PDCCH overhead is 8 symbols. because the SCH. . Huawei proprietary. The single cell downlink physical layer theory rate = 50*12*14*(1-(2/21+1/21))*6*2*1000*1 =82. 64QAM. BCH also take up some of the resources. the actual Downlink peak rate around 70Mbps Page 6 HUAWEI TECHNOLOGIES CO. 16/168=2/21) 1/21 PDCCH overhead (If downlink sub-frame PDCCH accounted for only a symbol. 2 * 2 MIMO. 82. No spread without permission.4Mbps 50  50 RB 12 One RB includes 12 sub-carrier 14  A sub-frame 14 symbol 6  64QAM each symbol represents 6 bits 2  2*2 MIMO 1000  1s=1000ms 2/21 RS overhead (total symbol of one RB=12*14=168. Page 7 . LTD. and consider the PUCCH occupied 4RB.5Mbps 46  46 RB 12 One RB includes 12 sub-carrier 14  A sub-frame 14 symbol 4  16QAM each symbol represents 4 bits 1  Coding rate 1/7Pilot overhead 1000  1s=1000ms UE cat4 does not support 64QAM and MIMO in uplink. the pilot overhead is 1/7. 16QAM. Huawei proprietary. the Coding rate is 1.. the uplink peak rate around 25Mpbs HUAWEI TECHNOLOGIES CO.Uplink Calculation Uplink maximum throughput = Number of RB × 12 (Number of Sub-carrier with one RB) × 14 (Number of Symbols with a Sub-frame) × ( 1 － RS overhead ) × Modulation symbols efficiency × 1000 (Number of Sub-frame in one second) × Coding rate Example: Calculate the FDD LTE system 10M.6Mbps. No spread without permission. None MIMO. The UE uplink physical layer theory rate = 46*12*14*(1-1/7)*4*1000*1=26. the uplink can reach the peak rate 25. in fact should also consider the impact of sounding and PRACH. Carrier Frequency EARFCN Calculation(3GPP : 36. This implies that the first 7.3-1 and NDL is the downlink EARFCN.7. 75 and 100 channel numbers at the lower operating band edge and the last 6.9 3800 3800 – 4149 1749. 50.9 22750 22750 – 22949 12 728 5000 5000 – 5179 698 23000 23000 – 23179 13 746 5180 5180 – 5279 777 23180 23180 – 23279 14 758 5280 5280 – 5379 788 23280 23280 – 23379 … 17 734 5730 5730 – 5849 704 23730 23730 – 23849 18 860 5850 5850 – 5999 815 23850 23850 – 23999 19 875 6000 6000 – 6149 830 24000 24000 – 24149 20 791 6150 6150 .3-1 E-UTRA channel numbers The channel raster is 100 kHz for all bands. No spread without permission.9 24450 24450 – 24599 … 33 1900 36000 36000 – 36199 1900 36000 36000 – 36199 34 2010 36200 36200 – 36349 2010 36200 36200 – 36349 35 1850 36350 36350 – 36949 1850 36350 36350 – 36949 36 1930 36950 36950 – 37549 1930 36950 36950 – 37549 37 1910 37550 37550 – 37749 1910 37550 37550 – 37749 38 2570 37750 37750 – 38249 2570 37750 37750 – 38249 39 1880 38250 38250 – 38649 1880 38250 38250 – 38649 40 2300 38650 38650 – 39649 2300 38650 38650 – 39649 NOTE: The channel numbers that designate carrier frequencies so close to the operating band edges that the carrier extends beyond the operating band edge shall not be used.7. FUL = FUL_low + 0.. Page 8 . 15 and 20 MHz respectively.3-1 and NUL is the uplink EARFCN. FDL = FDL_low + 0. 49.9 4750 4750 – 4949 1427.6449 832 24150 24150 . Huawei proprietary.65535. 5. Downlink Uplink E-UTRA FDL_low [MHz] NOffs-DL Range of NDL FUL_low [MHz] NOffs-UL Range of NUL Operating Band 1 2110 0 0 – 599 1920 18000 18000 – 18599 2 1930 600 600 . Carrier frequency and EARFCN The carrier frequency in the uplink and downlink is designated by the E-UTRA Absolute Radio Frequency Channel Number (EARFCN) in the range 0 . The relation between EARFCN and the carrier frequency in MHz for the downlink is given by the following equation.24449 21 1495. 24.104) Channel raster Table 5. where FDL_low and NOffs-DL are given in table 5.1199 1850 18600 18600 – 19199 3 1805 1200 1200 – 1949 1710 19200 19200 – 19949 4 2110 1950 1950 – 2399 1710 19950 19950 – 20399 5 869 2400 2400 – 2649 824 20400 20400 – 20649 6 875 2650 2650 – 2749 830 20650 20650 – 20749 7 2620 2750 2750 – 3449 2500 20750 20750 – 21449 8 925 3450 3450 – 3799 880 21450 21450 – 21799 9 1844.9 6450 6450 – 6599 1447.1(NDL – NOffs-DL) The relation between EARFCN and the carrier frequency in MHz for the uplink is given by the following equation where FUL_low and NOffs-UL are given in table 5. 14.4. 3. LTD. which means that the carrier centre frequency must be an integer multiple of 100 kHz.7. 74 and 99 channel numbers at the upper operating band edge shall not be used for channel bandwidths of 1. 25.1(NUL – NOffs-UL) HUAWEI TECHNOLOGIES CO. 10. 15.9 21800 21800 – 22149 10 2110 4150 4150 – 4749 1710 22150 22150 – 22749 11 1475. LTD. Huawei proprietary.FDL_low ) + NOffs-DL Say FDL (center Freq) = 1815 NDL (EARFCN)=10*(1815-1805)+1200 NDL (EARFCN)=1300 HUAWEI TECHNOLOGIES CO. No spread without permission.Example FDL (center Freq) = FDL_low + 0. Page 9 ..1(NDL (EARFCN) – NOffs-DL) Or NDL (EARFCN)= 10*(FDL (center Freq) . LTD. Page 10 . No spread without permission..IDLE Mode Behavior Idle Mode Overview PLMN Selection Cell selection & cell reselection System Information reception Tracking area registration Paging monitoring procedure HUAWEI TECHNOLOGIES CO. Huawei proprietary. Idle Mode Overview A UE that is powered on but does not have an RRC connection to the radio network is defined as being in idle mode. In the case of idle mode management, the eNodeB sends configurations by broadcasting system information, and accordingly, UEs select suitable cells to camp on. Idle mode management can increase the access success rate, improve the quality of service, and ensure that UEs camp on cells with good signal quality. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 11 PLMN Selection A PLMN identity consists of a Mobile Country Code (MCC) and a Mobile Network Code (MNC). When a UE is powered on or recovers from lack of coverage, after the cell search, the UE first selects the last registered PLMN and attempts to register on that PLMN. If the registration on the PLMN is successful, the UE shows the selected PLMN on the display, and now it can obtain service from an operator. If the last registered PLMN is unavailable or the registration on the PLMN fails, another PLMN can be automatically or manually selected according to the priorities of PLMNs stored in the USIM. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 12 Cell Selection & Reselection Cell search is a procedure in which a UE achieves time and frequency synchronization with a cell, obtains the physical cell ID, and learns the signal quality and other information about the cell based on the physical cell ID. Before selecting or reselecting a cell, a UE performs a cell search on all carrier frequencies. In the Long Term Evolution (LTE) system, Synchronization Channels (SCHs) are specially used for cell search. There are two types of SCH: Primary Synchronization Channel (P-SCH) and Secondary Synchronization Channel (S-SCH). The cell search procedure on SCHs is as follows: The UE monitors the P-SCH to achieve clock synchronization with a maximum synchronization error of 5 ms. Physical cell IDs have one-to-one mapping with primary synchronization signals. Therefore, the UE acquires the physical cell ID by monitoring the P-SCH. The UE monitors the S-SCH to achieve frame synchronization, that is, time synchronization with the cell. Cell ID groups have a one-to-one relation with secondary synchronization signals. Therefore, the UE acquires the number of the cell ID group to which the physical cell ID belongs by monitoring the S-SCH. The UE monitors the downlink reference signal to acquire the signal quality in the cell. The UE monitors the Broadcast Channel (BCH) to acquire other information about the cell. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 13  Qrxlevmin is the minimum required RX level (set in the eNodeB) in the cell. That is. expressed in decibels with reference to one milliwatt (dBm).Pcompensation   Qrxlevmeas is the measured RX level in the cell (RSRP).UE Maximum Output Power. Before a UE can select a cell to camp on. a UE needs to check whether a cell fulfills the cell selection criteria.  PMax is the maximum allowed transmit power of the UE in the cell. the RSRP of the cell must be higher than the user-defined minimum receive (RX) level Qrxlevmin of the cell. which was signaled from the associated cell in the higher-priority PLMN. The cell selection is based on the RSRP of the E-UTRAN cell.(Qrxlevmin + Qrxlevminoffset) . LTD.  Qrxlevminoffset is the offset to Qrxlevmin. expressed in units of dBm. the UE considers this offset parameter. It is used in uplink transmission. 0).. expressed in units of dBm. The value is expressed in decibels (dB). in the Srxlev evaluation.  Pcompensation is generated according to the function max(PMax . when camped on a cell in a VPLMN. No spread without permission.Cell Selection Criteria  During cell selection. This offset is taken into account when the UE attempts to camp on a cell in a higher-priority PLMN. Huawei proprietary. Page 14 .  The formula for cell selection decision is as follows:  Srxlev > 0  where Srxlev = Qrxlevmeas . HUAWEI TECHNOLOGIES CO. LTD..Cell Reselection  The signal strength of both serving cell and neighboring cells varies with the movement of UE and so the UE need to select the most suitable cell to camp on. This process is called cell reselection. Page 15 . No spread without permission. Huawei proprietary.  Cell reselection process:  Measurement Start criteria  Cell reselection criteria Intra frequency Interfrequency (within LTE) InterRAT ( LTE to Other RAT) HUAWEI TECHNOLOGIES CO. . No spread without permission.  If the intra frequency measurement triggering threshold is configured:  Srxlev > SintraSearch.   the UE does not perform intra frequency measurement. LTD.Intra frequency Measurement  If the intra frequency measurement triggering threshold is not configured. Srxlev = Smeas . Huawei proprietary. Srxlev <= SintraSearch. the UE performs intra frequency measurements always.SMin HUAWEI TECHNOLOGIES CO.  the UE perform intra frequency measurement. Page 16 . UE can get the serving cell & inter frequency / RAT neighbors’ priority For the high priority cells. UE perform inter frequency / RAT measurement From SIB.Inter Frequency // RAT Measurement  For the neighbor with higher priority   The UE always perform inter frequency / RAT measurement For the neighbor with Low or equal priority  If the threshold is not configured . LTD. The intra frequency cells have the same frequency priority. the UE always perform inter frequency/RAT measurement  If threshold is configured:  When Srxlev > SNonIntraSearch. No spread without permission. Huawei proprietary.. frequencies of different RATs must have different priorities HUAWEI TECHNOLOGIES CO. UE does not perform inter frequency / RAT measurement  When Srxlev <=SNonIntraSeach. UE measure them incase of serving cell signal is lower Than threshold. for low priority cells. Page 17 . UE measure them always. expressed in units of dB. expressed in units of dBm. The UE evaluates the neighboring cell only after the cell meets the cell selection criteria.Intra Frequency//Same Priority Cell Reselection Decision  A UE makes a cell reselection decision according to cell reselection criteria. expressed in units of dB. HUAWEI TECHNOLOGIES CO.  The cell-ranking criteria R_s for the serving cell and R_n for neighboring cells are defined as follows:   R_s = Qmeas. the UE checks whether the signal quality of a neighboring cell is higher than that of the serving cell.  Qhyst is the hysteresis for the serving cell used in the ranking criteria.  CellQoffset is the offset for the neighboring cell used in the ranking criteria. the UE does not consider this cell and other cells on the same frequency as candidates for reselection for a maximum of 300 seconds. it must be excluded from the candidate list.s is the measured RSRP of the serving cell. Page 18 . If the cell is barred.  According to the cell reselection criteria. and the UE does not consider the cell as a candidate for cell reselection.  During cell reselection.CellQoffset  where:  Qmeas. No spread without permission. Huawei proprietary..n . It is set in the eNodeB. LTD. When making a decision on reselection to an intra- frequency or equal-priority inter-frequency cell.  Qmeas.  More than one second has elapsed since the UE camped on the serving cell. the UE should reselect the new cell only if both the following conditions are met:  The new cell is ranked higher than the serving cell during the cell reselection time. It is set in the eNodeB. If the cell is unsuitable because it is part of the list of forbidden TAs for roaming or it does not belong to the registered PLMN or an EPLMN.n is the measured RSRP of the neighboring cell. expressed in units of dBm.s + Qhyst R_n = Qmeas. the UE needs to check whether access to that cell is allowed according to the cellAccessRelatedInfo Information Element (IE) in the SIB1. Note: If the highest cell is unsuitable because is part of list of forbidden Tac for roaming or it does not belong to registered PLMN or an EPLMN. Page 19 .Inter-RAT/Inter Frequency High Priority Cell Reselection Decision  For the high priority cells.. the UE does not consider this cell as candidate for reselection for a maximum of 300 seconds. HUAWEI TECHNOLOGIES CO. No spread without permission. “Sxlev” of a neighbor is higher than “ ThreshXHigh”  More than one second has elapsed since the UE camped on the serving cell. Huawei proprietary. the UE perform cell reselection if following conditions are met:   In “ reselection time”. LTD. Inter-RAT/Inter-Frequency low Priority Cell Reselection Decision  For low priority cells. but “Srxlev” value of the evaluated neighbor cell is greater than “ ThreshXLow”  More than one second has elapsed since the UE camped on the serving cell. No spread without permission. the UE perform cell reselection if the following condition are met:  No cell on a higher priority frequency meets the criteria  In “ reselection time”. “Srxlev” of the serving cell is lower than “ ThrshServLow”.. Page 20 . HUAWEI TECHNOLOGIES CO. LTD. Huawei proprietary. and System Frame Number (SFN) SIB1 SIB2 SIB3 SIB4 Parameters related to cell access and cell selection and scheduling information of SI messages Common radio parameters used by all the UEs in a cell Common cell reselection parameters for all the cells and intra-frequency cell reselection parameters Intra-frequency neighboring cell list.System Information Block Contents SI Block Content MIB Downlink bandwidth of a cell.. LTD. and intra-frequency cell reselection blacklist SIB5 Inter-frequency E-UTRA Absolute Radio Frequency Channel Number (EARFCN) list and reselection parameters of each EARFCN used for cell reselection Inter-frequency cell list and reselection parameters of each neighboring cell used for cell reselection Inter-frequency cell reselection blacklist SIB6 UMTS Terrestrial Radio Access (UTRA) Frequency Division Duplex (FDD) neighboring EARFCN list and reselection parameters of each EARFCN used for cell reselection UTRA Time Division Duplex (TDD) neighboring EARFCN list and reselection parameters of each EARFCN used for cell reselection SIB7 SIB8 GERAN neighboring EARFCN list and reselection parameters of each EARFCN used for cell reselection CDMA2000 pre-registration information CDMA2000 neighboring frequency band list and reselection parameters of each band used for cell reselection SIB9 SIB10 SIB11 CDMA2000 neighboring cell list of neighboring frequency band Name of the home eNodeB Earthquake and Tsunami Warning System (ETWS) primary notification ETWS secondary notification HUAWEI TECHNOLOGIES CO. Huawei proprietary. Physical HARQ Indication Channel (PHICH) parameters. Page 21 . reselection parameters of each neighboring cell used for cell reselection. No spread without permission. No spread without permission. Page 22 . Huawei proprietary.MIB i) MIB is transmitted at a fixed cycles (every 4 frames starting from SFN 0) HUAWEI TECHNOLOGIES CO.. LTD. MCC/MNC 2. No spread without permission. LTD. Page 23 .Cell identity Scheduling information of other SIBs i) SIB1 is also transmitted at the fixed cycles (every 8 frames starting from SFN 0).System Information Type-1 1.Tracking area code: TAC 3. SIB1 Parameters related to cell access and cell selection and scheduling information of SI messages HUAWEI TECHNOLOGIES CO. Huawei proprietary.. . LTD. Common cell reselection parameters for all the cells and intra-frequency cell reselection parameters Huawei proprietary. Page 24 .System Information (Sib-3) SIB3 HUAWEI TECHNOLOGIES CO. No spread without permission. System Information(Sib-4//Sib-6) SIB6 SIB4 Intra-frequency neighboring cell list. reselection parameters of each neighboring cell used for cell reselection.. UTRA Time Division Duplex (TDD) neighboring EARFCN list and reselection parameters of each EARFCN used for cell reselection Page 25 . UMTS Terrestrial Radio Access (UTRA) Frequency Division Duplex (FDD) neighboring EARFCN list and reselection parameters of each EARFCN used for cell reselection Huawei proprietary. and intrafrequency cell reselection blacklist HUAWEI TECHNOLOGIES CO. LTD. No spread without permission. Page 26 . which consist of MCC+MNC+TAC  TA in SIB1:  A UE informs the EPC of its Tracking area in 2 ways.Tracking Area Registration EPC send paging messages to all enodeB in the TA. No spread without permission. Huawei proprietary.  Attach/Detach  TA update (Periodic + Normal) HUAWEI TECHNOLOGIES CO. A TA is identified by Tracking area identifier (TAI).. LTD. Page 27 . HUAWEI TECHNOLOGIES CO. a detach procedure is initiated. After the detach procedure.. LTD. EPC no longer pages the UE.Attach//Detach  When a UE needs to obtain service from a network but is not registered to the network. Huawei proprietary. No spread without permission. the UE perform an attach procedure for TA registration  When the UE fails to access the EPC or the EPC doesn’t allow the access of the UE. . Huawei proprietary. LTD. Page 28 .TA Update (Periodic + Normal)  TA update are performed in the following situations:  The UE detects a new TA  The periodic TA update timer expires(T3412)  The UE perform reselection to an E-UTRAN cell from another RAT  The RRC connection is released because of load balancing  The information on UE capabilities stored in the ECP changes  The DRX parameter changes HUAWEI TECHNOLOGIES CO. No spread without permission. 2.Paging Frame (PF) Function of IMSI 3. LTD... which may contain one or multiple Paging Occasion(s). No spread without permission.Paging Occasion (PO) Paging Parameters in SIB2 SFN for PF SFN mod T = (T div N) x (UE_ID mod N) For Subframe PO The subframe number i_s of a PO is derived from the following formula: i_s =Floor (UE_ID/N) mod Ns *Occasion (PO) is a subframe where there may be P-RNTI transmitted on PDCCH addressing the paging message..::= CHOICE [sib2] | +-sib2 ::= SEQUENCE [00] . Page 29 .DefaultPagingCycle (T)... * Paging Frame (PF) is one Radio Frame. HUAWEI TECHNOLOGIES CO. DRX Cycle Coefficient..Paging Monitoring Procedure Key Concept 1. BCCH-DL-SCH-Message ::= SEQUENCE +-message ::= CHOICE [c1] +-c1 ::= CHOICE [systemInformation] +-systemInformation ::= SEQUENCE +-criticalExtensions ::= CHOICE [systemInformation-r8] +-systemInformation-r8 ::= SEQUENCE [0] +-sib-TypeAndInfo ::= SEQUENCE OF SIZE(1. | | +-pcch-Config ::= SEQUENCE | | | +-defaultPagingCycle ::= ENUMERATED [rf128] | | | +-nB ::= ENUMERATED [oneT] Huawei proprietary..maxSIB[32]) [1] | +. 2T.SFN for PF SFN mod T = (T div N) x (UE_ID mod N) Meaning of Parameters For Subframe PO The subframe number i_s of a PO is derived from the following formula: i_s =Floor (UE_ID/N) mod Ns T=DRX Cycle N=N is min(T. or T/32. SIB-2 HUAWEI TECHNOLOGIES CO. T. The NB parameter specifies the number of PO subframes in a DRX cycle. Based on the actual configuration on the eNodeB.. LTD. T/16.NB). NB can be set to 4T. T/4. Huawei proprietary. No spread without permission. UE_ID is IMSI mod 1024. Ns =max(1.NB/T). Page 30 . T/2. T/8. LTD. No spread without permission. Page 31 .. Huawei proprietary.Understanding of NB HUAWEI TECHNOLOGIES CO. Page 32 .890625) mod 1=7 mod 1= 0 9 10 11 12 13 … …. 114 … … 123 124 125 126 127 P PF PF PF PF PF PF PF PF PF PF PF PF PF PF PF PF PF PF F PF PF PF PF PF PF 0 1 2 3 4 5 6 7 8 0 HUAWEI TECHNOLOGIES CO. LTD.NB/T)  Ns=max(1..SFN for PF SFN mod T = (T div N) x (UE_ID mod N) Example IMSI: IMSI(448835805669362) N=N is min(T. ….T)  T=128 Ns =max(1.NB/T) Ns=max(1. 1 2 3 4 5 6 7 8 9 PO Huawei proprietary. No spread without permission.NB)  N=min(T.T/T)  1 UE_ID is IMSI mod 1024  (448835805669362) mod 1024=1010 For Subframe PO The subframe number i_s of a PO is derived from the following formula: i_s =Floor (UE_ID/N) mod Ns SFN mod T=(128 div 128) x (1010 mod 128)= 114 i_s=Floor(UE_ID/N) mod Ns= Floor(1010/128) mod 1= Floor(7. . No spread without permission.Connected Mode HUAWEI TECHNOLOGIES CO.  Handover  Power Control (DL)  Scheduling (DL) Huawei proprietary. LTD. Page 33 . Handover Procedure Mobility Management Overview Intra Frequency handover Inter Frequency handover Inter RAT handover HUAWEI TECHNOLOGIES CO. LTD. Huawei proprietary. Page 34 .. No spread without permission. Page 35 . LTD.Mobility Management Overview HUAWEI TECHNOLOGIES CO.. No spread without permission. Huawei proprietary. .Handover Procedures Entities mobility robust optimization (MRO) HUAWEI TECHNOLOGIES CO. Page 36 . No spread without permission. Huawei proprietary. LTD. . Page 37 . Huawei proprietary. No spread without permission. LTD.Measurement Triggering Only voice HUAWEI TECHNOLOGIES CO. Page 38 . No spread without permission. LTD.. Huawei proprietary.Handover Events HUAWEI TECHNOLOGIES CO. SS RACH Response Cell 2 17 UE ---> SS RRCConnectionReconfigurationComplete Cell 2 18 UE <--.SS RRC Connection Reconfiguration Cell 1 10 UE ---> SS RRCConnectionReconfigurationComplete Cell 1 11 UE <--. No spread without permission.SS RRC Connection Reconfiguration Cell 1 12 UE ---> SS RRCConnectionReconfigurationComplete Cell 1 13 UE ---> SS Measurement Report Cell 1 14 UE <--. to setup/modify/release measurement Main IE: Measurementconfiguration Mobilitycontrolinformation Nas-DedicatedInformation RadioResourceConfiguration Securityconfiguration Ue-RelatedInformation HUAWEI TECHNOLOGIES CO.SS RRC Connection Reconfiguration Cell 1 15 UE ---> SS PRACH Cell 2 16 UE <--. LTD. Page 39 Memo reactivating default EPS Bearer Measurement Control for Target Cell Handover Command PASS/FAIL ..SS ueCapabilityEnquiry Cell 2 19 UE ---> SS ueCapabilityInformation Cell 2 20 UE ---> SS ulInformationTransfer + Detach Request Cell 2 21 UE <--. Step Direction Message Target Cell 1 UE <---> SS < Power On and Registration > Cell 1 2 UE <---> SS < Now UE is in IDLE mode > Cell 1 3 UE <--.SS Security Mode Command Cell 1 8 UE ---> SS Security Mode Complete Cell 1 9 UE <--.SS Paging Cell 1 4 UE ---> SS RRC Connection Request Cell 1 5 UE <--.SS RRC Connection Setup Cell 1 6 UE ---> SS RRC Connection Setup Complete Cell 1 7 UE <--.Key Concept RRC Connection Reconfiguration is use to Modify/establish/release RB/to perform Handover.SS RRC Connection Release Cell 2 Huawei proprietary. Huawei proprietary. the eNodeB delivers the measurement gap configuration. The UE performs inter-frequency or inter-RAT measurements only within the measurement gaps. LTD. and then the UE starts gap-assisted measurements accordingly. within which the UE performs measurements HUAWEI TECHNOLOGIES CO. and consequently one UE can receive the signals on only one frequency at a time. No spread without permission.Gap Mode A measurement gap is a time period during which the UE performs measurements on a neighboring frequency of the serving frequency.. When inter-frequency or inter-RAT measurements are triggered. Measurement gaps are applicable to interfrequency and inter-RAT measurements. and TGAP denotes the gap width. Page 40 . As shown above. One UE normally has only one receiver. Tperiod denotes the repetition period of measurement gaps. Intra-Frequency handover Event A3 will be trigger for Intra-frequency handover. No spread without permission. HUAWEI TECHNOLOGIES CO. LTD. Huawei proprietary.. Page 41 . Huawei proprietary. No spread without permission. Page 42 .Handover Procedure LTE Vs WCDMA Jargon RRC Connection Reconfiguration == Measurement Control Measurement Report == Measurement Report RRC Connection Reconfiguration == Physical Channel Reconfiguration or ActiveSetUpdate RRC Connection Reconfiguration Complete == Physical Channel Reconfiguration Complete or ActiveSetUpdateComplete HUAWEI TECHNOLOGIES CO.. LTD. Page 43 .HUAWEI TECHNOLOGIES CO. LTD. No spread without permission. Huawei proprietary.. Page 44 . No spread without permission.. Huawei proprietary.HUAWEI TECHNOLOGIES CO. LTD. the UE detaches the connection from the source eNodeB.. In the case of inter-eNodeB handover. LTD. to the target eNodeB. Data forwarding prevents a decrease in the data transfer ratio and an increase in the data transfer delay that are caused by user data loss during the handover. The source eNodeB then forwards the uplink (UL) data that is received out of order and the DL data to be transmitted. Huawei proprietary. Intra-eNodeB handovers do not require data forwarding. No spread without permission. the source eNodeB selects a data forwarding path by using the X2/S1 adaptation mechanism. Page 45 . HUAWEI TECHNOLOGIES CO.The data forwarding process is as follows: After the source eNodeB sends a handover command to the UE. the UE performs a cell selection procedure and then initiates a procedure of RRC connection reestablishment towards the selected cell. If the eNodeB accepts the re-establishment request.When a handover fails. No spread without permission. thus avoiding drop of the call caused by the handover failure. Page 46 . Huawei proprietary. LTD. HUAWEI TECHNOLOGIES CO.. The eNodeB makes a decision based on whether the context of the UE is present or not. the UE accesses the selected cell. No spread without permission. LTD. Page 47 ..Inter-Frequency Measurement HUAWEI TECHNOLOGIES CO. Huawei proprietary. event A2 triggers inter-frequency measurements. it can be defined separately with RSRP or RSRQ HUAWEI TECHNOLOGIES CO. Huawei proprietary. Page 48 . Ms: The measurement result of the serving cell Hys: The hysteresis for event A2 Thresh: The threshold for event A2. LTD.Event A2 Triggering Algorithm In a coverage-based inter-frequency handover. The triggering of this event indicates that the signal quality in the serving cell is lower than a specified threshold. No spread without permission.. LTD. Huawei proprietary..Event A1 Stop Algorithm Ms: The measurement result of the serving cell Hys: The hysteresis for event A1 HUAWEI TECHNOLOGIES CO. Page 49 . No spread without permission. . Ocn: The cell-specific offset for the neighboring cell. No spread without permission. LTD. Hys: The hysteresis for event A4 Thresh: The threshold for event A4 HUAWEI TECHNOLOGIES CO. Huawei proprietary. Page 50 .Event A4 Handover Execution Mn: The measurement result of the neighboring cell. Ofn: The frequency-specific offset for the frequency of the neighboring cell. Page 51 . Huawei proprietary.Inter-RAT Measurement Measurement Trigger HUAWEI TECHNOLOGIES CO. No spread without permission.. LTD. Huawei proprietary.Measurement Object HUAWEI TECHNOLOGIES CO. LTD.. No spread without permission. Page 52 . Handover Trigger  B1 Event Mn: The measurement result of the neighboring cell Ofn: The frequency-specific offset for the frequency of the neighboring cell Hys: The hysteresis for event B1. LTD. The hysteresis values for inter-RAT handovers to UTRAN. Page 53 .. No spread without permission. HUAWEI TECHNOLOGIES CO. Huawei proprietary. LTE UMTS PS Handover Flow HUAWEI TECHNOLOGIES CO. No spread without permission.. LTD. Huawei proprietary. Page 54 . LTD.. Page 55 . No spread without permission.Power Control HUAWEI TECHNOLOGIES CO. Huawei proprietary. LTD. Page 56 . No spread without permission. Huawei proprietary..Classification of Power Control HUAWEI TECHNOLOGIES CO. PBCH. LTD. and in fact. expands cell capacity. Dynamic power control lowers interference. synchronization signal. Dynamic power control Dynamic power control is applicable to the PHICH and the PDCCH and PDSCH that carry dedicated information sent to UEs.Downlink Power Control Classification The configured power must meet the requirements for the downlink coverage of the cell Fixed power assignment Fixed power assignment is applicable to the cell-specific reference signal. Users configure fixed power based on channel quality. PCFICH. this is our recommendation because the AMC function can also meet the requirement of QoS. Page 57 . Huawei proprietary. No spread without permission. these channels can also support fix power assignment. However. and the PDCCH and PDSCH that carry common information of the cell. HUAWEI TECHNOLOGIES CO. and increases coverage while meeting users' QoS requirements.. The configured power must meet the requirements for the downlink coverage of the cell. LTD. which indicates the Energy Per Resource Element (EPRE) of the cell-specific reference signal. No spread without permission.Cell Specific RS Power Setting The cell-specific reference signal is transmitted in all downlink subframes. The power for the cell-specific reference signal is set through the ReferenceSignalPwr parameter. The signal serves as a basis for downlink channel estimation. Huawei proprietary.. HUAWEI TECHNOLOGIES CO. Page 58 . which is used for data demodulation. No spread without permission.Synchronization Signal Power Setting The synchronization signal is used for cell search and system synchronization. LTD. HUAWEI TECHNOLOGIES CO. the Primary Synchronization Channel (P-SCH) and the Secondary Synchronization Channel (S-SCH). The offset of the power for the P-SCH and S-SCH against the power for the cell-specific reference signal is set through the SchPwr parameter. Huawei proprietary.. There are two types of synchronization signals. Page 59 . Page 60 . antenna configuration.. and frame number. The power for the PCFICH is set through the PcfichPwr parameter. LTD. such as the cell bandwidth. broadcast messages are sent in each frame. The offset of the power for the PBCH against the power for the cell-specific reference signal is set through the PbchPwr parameter. which indicates an offset of the power for the PCFICH against the power for the cell-specific reference signal. The PCFICH carries the number of OFDM symbols used for PDCCH transmission in a subframe. The PCFICH is always mapped to the first OFDM symbol of each subframe. No spread without permission.PBCH/PCFICH Power Setting On the PBCH. Huawei proprietary. HUAWEI TECHNOLOGIES CO. The messages carry the basic system information of the cell. PDCCH/PDSCH Power Setting HUAWEI TECHNOLOGIES CO. LTD.. Huawei proprietary. Page 61 . No spread without permission. Huawei proprietary.Dynamic Power Control .PHICH HUAWEI TECHNOLOGIES CO.. Page 62 . LTD. No spread without permission. Huawei proprietary. No spread without permission.PDCCH When PDCCH carry the following dedicate info. Page 63 .Dynamic Power Control . LTD. power control should be performed to ensure the receive reliability Uplink scheduling information (DCI format 0) Downlink scheduling information (DCI format 1/1A/1B/2/2A) PUSCH/PUCCH TPC commands (DCI format 3/3A) HUAWEI TECHNOLOGIES CO.. LTD..PDSCH Power Presentation Regarding power control for the PDSCH. No spread without permission. HUAWEI TECHNOLOGIES CO. Huawei proprietary. Above table shows the OFDM symbol indexes within a slot where the ratio of the EPRE to the EPRE of RS is denoted by ρA or ρB. Page 64 . the OFDM symbols on one slot can be classified into two types. LTD.. Huawei proprietary. Neighbor relations are classified into normal and abnormal neighbor relations.Automatic Neighbor Relation ANR is a self-optimization function. PCI collisions. No spread without permission. It automatically maintains the integrity and effectiveness of neighbor cell lists (NCLs) to increase handover success rates and improve network performance. PCI collisions. and abnormal neighboring cell coverage. which reduces the costs of network planning and optimization. Abnormal neighbor relations exist in the cases of missing neighboring cells. and abnormal neighboring cell coverage and maintains neighbor relations. ANR automatically detects missing neighboring cells. ANR does not require manual intervention. In addition. Page 65 . unstable neighbor relations. ANR classifications HUAWEI TECHNOLOGIES CO. Concepts Related to ANR -NCL -NRT -TempNRT -BlackList -HO Black List -X2 Black List -WhiteList -HO White List -X2 White List -PCI Collision -Abnormal Neighbor Cell coverage HUAWEI TECHNOLOGIES CO. LTD. Page 66 . Huawei proprietary.. No spread without permission. The NCL is used as a basis for creating neighbor relations. and EARFCNs of the neighboring cells. NCLs are classified into intra-RAT NCLs and inter-RAT NCLs.. Neighboring cells in the NCL can be automatically managed (for example. HUAWEI TECHNOLOGIES CO. No spread without permission. They can also be managed manually. LTD.  An NCL includes the ECGIs (for E-UTRAN cells) or CGIs (for inter-RAT cells).NCL  An NCL of a cell contains the information about the neighboring cells of a cell. Page 67 . or modified) by ANR. deleted.  The eNodeB adds newly detected neighboring cells to the NCL. Huawei proprietary. PCIs. Unless otherwise stated. Each cell has one intra-RAT NCL and multiple inter-RAT NCLs. added. neighboring cells mentioned in this document exclude intra-eNodeB neighboring cells. Each cell has one intra-RAT intra-frequency NR one intra-RAT inter-frequency NRT. and multiple inter-RAT NRTs. Page 68 . SN LCI Local Cell PLMN TCI No Remove No HO 1 LCI#1 46001 TCI#1 TRUE TRUE 2 LCI#1 46001 TCI#2 FALSE FALSE 3 LCI#1 46001 TCI#3 TRUE TRUE Huawei proprietary. No spread without permission. shows an example of the NRT.. The information in this table is for reference only.NRT An NRT of a cell contains the information about the neighbor relations between a cell and its neighboring cells NRTs are classified into intra-RAT NRTs and inter-RAT NRTs. LTD. The intra-RAT intra-frequency NRT and intra intra-frequency NRT are referred to as the intra-RAT NRT in this document. Table 3-1 An example of the NRT HUAWEI TECHNOLOGIES CO. No spread without permission. HUAWEI TECHNOLOGIES CO.. LTD. Each cell has an intra-RAT intra-frequency TempNRT and an intra-RAT inter-frequency TempNRT but does not have an inter-RAT TempNRT. the eNodeB regularly maintains the neighbor relation in the TempNRT. After detecting a new intra-RAT neighbor relation. If the new neighbor relation is normal. Huawei proprietary.TempNRT A TempNRT is a temporary NRT. the eNodeB adds it to the intra-RAT NRT. The Intra-RAT intrafrequency TempNRT and intra-RAT intra-frequency TempNRT are referred to as the intra-RAT TempNRT in this document. the eNodeB adds it to the intra-RAT TempNRT. It has the same data structure as the NRT. Page 69 . Then. HUAWEI TECHNOLOGIES CO. Page 70 . No spread without permission. X2 Blacklist An X2 blacklist contains the information about an eNodeB and its neighboring eNodeBs.Blacklist HO Blacklist An HO blacklist contains the information about neighbor relations that cannot be used for a handover or removed automatically from the NRT by ANR. Huawei proprietary. it will be removed automatically. The neighbor relations in the HO blacklist must meet the following conditions: NO Remove = TRUE NO HO = TRUE A neighbor relation can be added to the HO blacklist manually.. X2 interfaces cannot be set up automatically between the eNodeB and the neighboring eNodeBs. LTD. If an X2 interface has been set up. The neighbor relations in the HO whitelist must meet the following conditions: NO Remove = TRUE NO HO = FALSE A neighbor relation can be added to the HO whitelist manually. No spread without permission.Whitelist HO Whitelist An HO whitelist [1] contains the information about neighbor relations that can be used for a handover but cannot be removed automatically from the NRT by ANR. Page 71 . Huawei proprietary. X2 Whitelist An X2 whitelist contains the information about an eNodeB and its neighboring eNodeBs.. The X2 interfaces established between the eNodeB and the neighboring eNodeBs cannot be removed automatically HUAWEI TECHNOLOGIES CO. LTD. PCI A PCI is the identifier of a physical cell. The PCI of an E-UTRAN cell corresponds to: The primary scrambling code (PSC) of a UTRAN FDD cell The cell ID of a UTRAN TDD cell The base transceiver station identity code (BSIC) of a GSM/EDGE radio access network (GERAN) cell The pseudo number (PN) offset of a CDMA cell HUAWEI TECHNOLOGIES CO. Therefore. No spread without permission. PCI collisions occur inevitably. PCI collisions negatively affect handover performance and the handover success rate. LTD. according to reference document.. Page 72 . A maximum of 504 PCIs are supported. Huawei proprietary. For details about PCI collision handling. . Page 73 . Huawei proprietary. No spread without permission. LTD. The signals of an abnormal neighboring cell are generally unstable and therefore the success rate of handovers to this cell is low. HUAWEI TECHNOLOGIES CO.Abnormal Neighboring Cell Coverage Abnormal neighboring cell coverage (also called cross-cell coverage) refers to the coverage of a cell that is not a neighboring cell of the serving cell but can be detected by a UE in the serving cell. l In mountains.. the signals of the umbrella cell cover lower cells. The coverage of neighboring cells may be abnormal in any of the following scenarios: l The antenna tilt or orientation changes because of improper installation or a natural phenomenon such as strong wind. The eNodeB regards this cell as a neighboring cell of the serving cell and therefore attempts to add the neighbor relation to the NRT. Huawei proprietary. Page 74 .Classification of ANR  Intra-RAT ANR  Intra-RAT Fast ANR  Inter-RAT ANR  Inter-RAT Fast ANR HUAWEI TECHNOLOGIES CO.. LTD. No spread without permission. The UE detects that the PCI of cell B meets the measurement configuration and reports it to the source eNodeB. The source eNodeB adds the newly detected neighboring cell of cell B to the intra-RAT NCL of cell A and adds the neighbor relation to the intra-RAT TempNRT HUAWEI TECHNOLOGIES CO. Source 2. and PLMN ID list of cell B over the broadcast channel (BCH). TAC. The source eNodeB schedules appropriate idle periods to allow the UE to read the ECGI. The source eNodeB delivers the inter-frequency measurement configuration to the UE and requests the UE to measure inter-frequency neighboring cells that meet the measurement configuration. The UE reports the detected ECGI.Intra-RAT ANR 1. 5. using the newly discovered PCI as a parameter.. No spread without permission. Then. the procedure ends. Tracking Area Code (TAC). to read the ECGI. 3. TAC. and PLMN ID list of cell B to the source eNodeB. 4. If yes. Page 75 Neighbor . and PLMN ID list of cell B. the following steps continue. LTD. If no. The source eNodeB instructs the UE. the source eNodeB checks whether the intraRAT NCL of cell A includes the PCI of cell B. Huawei proprietary. HUAWEI TECHNOLOGIES CO. Huawei proprietary. LTD. the eNodeB can obtain the information about all neighboring cells with the signal quality reaching or exceeding certain RSRP (it is specified by the FastAnrRsrpThd parameter) based on the reporting of periodic UE measurements. Page 76 .Intra-RAT Fast ANR Before a UE performs handovers. This reduces the impact of event-triggered UE measurements on handover performance when the UE performs handovers.. No spread without permission. Inter-RAT ANR 1. The source eNodeB delivers the inter-RAT measurement configuration (including target RATs and EARFCNs) to the UE, activates the measurement gap mode, and instructs the UE to measure the neighboring cells that meet the measurement configuration. 2. The UE detects that the PCI of cell B meets the measurement configuration and reports it to cell A. If the source eNodeB detects that its NCL does not include the PCI of cell B, it proceeds to the following step. 3. The source eNodeB instructs the UE, using the newly discovered PCI as a parameter, to read other parameters of cell B, such as CGI. 4. The source eNodeB schedules appropriate measurement gaps to allow the UE to read the CGI and other parameters of cell B over the BCH. 5. The UE reports the source eNodeB the CGI and other parameters of cell B. The source eNodeB adds the newly detected neighboring cell to its inter-RAT NCL and adds the neighbor relation to the inter-RAT NRT. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 77 Inter-RAT Fast ANR After inter-RAT fast ANR is activated, the eNodeB delivers the inter-RAT measurement configuration to the UE and instructs the UE to detect neighboring GERAN, UTRAN, and CDMA cells by using periodic measurements. The principles of inter-RAT fast ANR are the same as those of intra-RAT fast ANR HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 78 PCI Collision Handling A PCI collision occurs if two cells in an NCL have the same PCI but different ECGIs. PCI collisions may be caused by improper network planning or abnormal neighboring cell coverage (also known as cross-cell coverage). If two intra-frequency neighboring cells have the same PCI, interference will be caused. When a PCI collision occurs, the eNodeB cannot determine the target cell for a handover. This deteriorates the handover performance and reduces the handover success rate. Therefore, eliminating PCI collisions is an important issue in network optimization. After a PCI collision is eliminated, the PCI is unique in the coverage area of the cell and unique in the neighbor relations of the cell. PCI collision detections are triggered after intra-RAT ANR updates neighboring cells. PCI collision handling involves automatically detecting PCI collisions and reallocating PCIs. PCI reallocation is a process of allocating a new PCI to a cell whose PCI collides with the PCI of another cell. This aims to eliminate PCI collisions. If Optimization Analysis Mode is set to Immediate or Scheduled, the M2000 triggers PCI reallocation in the mode specified by the value of Optimization Analysis Mode. The M2000 also provides suggestions on PCI reallocation upon receiving a PCI collision alarm. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 79 Overview ICIC All physical resource blocks (PRBs) occupied by user equipment (UEs) in a cell are mutually orthogonal in the frequency domain. No spread without permission. in which case every cell can provide services over the entire system band. The interference mitigation enhances the network coverage and improves the CEU throughput HUAWEI TECHNOLOGIES CO. However.. Huawei proprietary. inter-cell interference must be mitigated. Therefore. LTD. are preferentially scheduled in the cell edge bands to mitigate inter-cell interference. which cause high interference or may be sensitive to interference. ICIC divides the entire system band into three frequency bands and uses different frequency bands at the edge of neighboring cells. Page 80 . therefore. For cell edge users (CEUs). inter-cell interference is relatively high because the frequency reuse factor is 1. intra-cell interference is very low. CEUs. to increase the cell capacity and CEU throughput. the impact of the inter-cell interference is especially severe. ICIC UL DL Static Dynamic Static Dynamic ICIC is a technology that collaborates with power control and media access control (MAC) scheduling technologies to mitigate inter-cell interference. No spread without permission. iii) Power control and MAC scheduling collaborate to allocate PRBs to UEs based on cell edge bands and UE types. ii) Edge band mode assignment is a technique of allocating different edge bands to neighboring cells. Page 81 ..Technical Principles of ICIC Key Concept: A3 Event for ICIC CEU/CCU Power Control MAC Scheduling The relationships between the key techniques are described as follows: i) CEU/CCU identification is a technique of identifying the UE type (CEU or CCU) based on event A3. PRBs in edge bands are mainly allocated to CEUs. Huawei proprietary. HUAWEI TECHNOLOGIES CO. Edge band adjustment is a technique of expanding or shrinking the edge band of a cell based on inter-cell interference and the cell load. and those in center bands are mainly allocated to CCUs. Edge band mode assignment and edge band adjustment collaborate to determine the edge band of each cell. LTD. Page 82 . a UE is recognized as a CCU by the serving cell. HUAWEI TECHNOLOGIES CO. ii) If an ICIC event A3 report contains the measurement result about at least one neighboring cell. the eNodeB starts to use event A3 for ICIC (referred to as ICIC event A3 in this document) to determine whether the UEs are CEUs or CCUs. the eNodeB treats the UE as a CEU. eNodeBs identify CEUs and CCUs based on ICIC event A3 as follows: i) If an ICIC event A3 report contains the measurement result only about the serving cell of a UE. the UE is recognized as a CEU by the target cell. After a short period following the initial access or handover.CEU/CCU Identification Principles When initially accessing a network. No spread without permission.. the eNodeB treats the UE as a CCU. LTD. after a handover. An example of this is when the UE moves from the cell edge to the cell center. Huawei proprietary. LTD. Page 83 .ICIC Event A3 Based on RSRP Measurement HUAWEI TECHNOLOGIES CO.. No spread without permission. Huawei proprietary. Huawei proprietary. Page 84 ..Entering Condition for ICIC Event A3 HUAWEI TECHNOLOGIES CO. LTD. No spread without permission. Leaving Condition for ICIC Event A3 HUAWEI TECHNOLOGIES CO.. No spread without permission. Huawei proprietary. LTD. Page 85 . LTD.More Parameter of ICIC Event A3 HUAWEI TECHNOLOGIES CO. No spread without permission.. Huawei proprietary. Page 86 . There are three edge band modes: MODE1. neighboring cells use different edge band modes so that CEUs in the cells are served by different frequency bands in the system band. The bandwidth of each band is about 1/3 of the physical downlink shared channel (PDSCH) or physical uplink shared channel (PUSCH) bandwidth. Huawei proprietary.. LTD. The policy can be either dynamic ICIC or static ICIC. Page 87 . HUAWEI TECHNOLOGIES CO. whichrepresent low-. and high-frequency bands. and MODE3. MODE2. If there are three cells per eNodeB. the use of three edge band modes can eliminate inter-cell interference in the frequency domain. respectively. No spread without permission. Theoretically.Edge Band Mode Assignment Edge band mode assignment is a technique of allocating different edge bands to neighboring cells. The PRBs available to CEUs in a cell using a specific edge band mode correlate with the ICIC policy and system bandwidth. medium-. as shown in Figure 3-2. Page 88 . ii) Edge band shrinking condition − Active shrinking: The current cell actively shrinks its edge band if its edge load is relatively low.Edge Band Adjustment (Only in Dynamic ICIC) There are two ICIC policies: static ICIC and dynamic ICIC.. and green grids with Y denote the PRBs that CEUs in the current cell actually use beyond the edge band defined in static ICIC. The difference between them is that only dynamic ICIC adjusts edge bands. Figure is used as an example to describe edge load evaluation: Yellow grids for the current cell represent the PRBs defined in static ICIC. − Passive shrinking: When the neighboring cell expands its actual edge band within the edge band defined in static ICIC. the current cell determines that the number of PRBs required by CEUs is greater than the number of cell edge PRBs defined in static ICIC. HUAWEI TECHNOLOGIES CO. i) Edge band expansion condition The current cell expands its edge band if its edge band is heavily loaded while the edge bands in its neighboring cells are lightly loaded. No spread without permission. In this situation. the current cell shrinks its edge band if the PRBs used by the current and neighboring cells collide. Huawei proprietary. LTD. Figure shows an example of passive shrinking. The edge load of the current cell is high while the edge load of the neighboring cell is low. On the premise of guaranteed quality of service (QoS).Scheduling The eNodeB implements scheduling at the media access control (MAC) layer and provides time-frequency resources for uplink and downlink through scheduling. No spread without permission.. Huawei proprietary. LTD. Page 89 . scheduling aims to transmit data on the channel with better quality and maximize system throughput by using different channel qualities among UEs. HUAWEI TECHNOLOGIES CO. . In operating networks Page 90 . Usage Scenario To verify the maximum system throughput RR None Each UE has equal opportunity to be scheduled. and QoS requirement HUAWEI TECHNOLOGIES CO. LTD. To verify the system throughput and fairness EPF Service rate. channel quality. Huawei proprietary. To verify the upper limit of scheduling fairness PF Service rate and channel quality The UE with a small ratio between the service rate and channel quality has a higher priority in scheduling.Scheduling Policies  Max C/I  l Round robin (RR)  l Proportional fair (PF)  l Enhanced proportional fair (EPF) Scheduling Policy Max C/I Effect Factor Channel quality Scheduling Priority The UE with better channel quality has a higher priority in scheduling. No spread without permission. Huawei proprietary.Scheduling Scheme  Semi Persistent  Dynamic Semi-Persistent Scheduling Semi-persistent scheduling is introduced to reduce the overhead of control signaling. Therefore.. regular packet arrival. Dynamic Scheduling In dynamic scheduling. By adopting semipersistent scheduling. HUAWEI TECHNOLOGIES CO. Dynamic scheduling has no requirements on the size and arrival time of data packets. scheduling is performed every Transmission Time Interval (TTI) of 1 ms and all the UEs to be scheduled are notified with the scheduling information through control signaling within this TTI. such as the Voice over IP (VoIP). and low delay requirements. VoIP services can save the overhead of control signaling and increase the VoIP capacity. LTD. Page 91 . dynamic scheduling is applicable for all services. Semi-persistent scheduling is a process where one user uses the same time-and-frequency resources in a specified semi-persistent scheduling period (20 ms in Huawei eNodeB) until they are released. Semi-persistent scheduling is mainly used for processing services with a constant rate. No spread without permission. DL Scheduler Downlink scheduling allocates time-and-frequency resources at the Physical Downlink Shared Channel (PDSCH) for transmission of system messages and downlink data. Page 92 . the downlink resource efficiency is low. Downlink scheduling described in this chapter is based on the EPF scheduling strategy. HUAWEI TECHNOLOGIES CO. if reported CQIs cannot properly reflect the actual channel conditions. Therefore. In addition. Huawei proprietary. LTD. the scheduling priority and Modulation and Coding Scheme (MCS) are determined based on the amount of data at the Radio Link Control (RLC) layer. No spread without permission. the UE channel quality information is obtained through the CQIs reported by the UE. The prioritization and MCS selection of scheduling depend on the CQI information.. Downlink scheduling calculates available scheduling resources based on the current remaining power. QoS requirements of bearers. and UE channel quality. In downlink scheduling. Huawei proprietary. paging messages. Common control messages consist of broadcast messages. SRB1. The scheduling of IMS signaling is the same as that of UE-level control messages. HUAWEI TECHNOLOGIES CO. LTD. Page 93 . and SRB2.. UE-level control messages consist of Signaling Radio Bearer 0 (SRB0). Semi-persistent scheduling is used in the talk spurts of the VoIP services. HARQ retransmission data Other initial transmission services Other initial transmission services refer to the initial transmission services of other QCIs excluding VoIP services and IMS signaling. Control-plane data and IMS signaling Control-plane data consists of common control messages and UE-level control messages. and random access response messages. No spread without permission.DL Scheduling VoIP service The VoIP service experiencing semi-persistent scheduling has the highest priority. VOIP HUAWEI TECHNOLOGIES CO. No spread without permission.. LTD. Huawei proprietary. Page 94 . . Control-plane data consists of common control messages and UE-level control messages. Page 95 . LTD. No spread without permission.Control-Plane Data and IMS Signaling The scheduling priority of control-plane data is only lower than that of VoIP services. Huawei proprietary. Control-plane data is subject to dynamic scheduling. Handover and Power control is also UELevel Control messages. HUAWEI TECHNOLOGIES CO. The scheduling of IMS signaling is the same as that of UE-level control messages. No spread without permission..HAQR Retransmission Data HUAWEI TECHNOLOGIES CO. Huawei proprietary. LTD. Page 96 . Page 97 .. Huawei proprietary. LTD.Total Process of Other Services Prioritization *UEs that experience semi-persistent scheduling in the current TTI *UEs that experience HARQ retransmission scheduling in the current TTI *UEs that run out of HARQ process numbers *UEs that enter the measurement gap *UEs that enter the DRX dormant period *UEs that stay out of synchronization and have failed radio links Rate of non-GBR service > Min_GBR (DLMINGBR) Within Time T: Rate of GBR service > T*{Maximum number of DL-SCH transport block bits received within a TTI} HUAWEI TECHNOLOGIES CO. No spread without permission. LTD. The UE with a higher level set by operators has a higher priority in scheduling. Huawei eNodeB can distinguish between Bit Torrent (BT) and non-BT services using a switch under the DlSchSwitch parameter. Huawei proprietary.Prioritization of Remaining Services Prioritization of Non-GBR Service CQI The service with higher spectral efficiency of the corresponding wideband CQI has a higher priority. Larger weight factor leads to higher priority of scheduling HUAWEI TECHNOLOGIES CO. No spread without permission.. ARP Allocation Retention Priority Weight factor {Bit Torrent Vs Non-Bit Torrent And/Or QCI} Weight factors in downlink scheduling are classified into QCI class weight factors and service type-based weight factors. Max C/I Average rate of non-GBR services The non-GBR service with a larger average rate has a lower priority. PF UE differentiation factor The UE differentiation factor reflects the priority of UEs of different levels. SPI Service Priority Indicator Max C/I + PF+ARP+SPI=ePF Page 98 . The PDB value depends on the QCI. No spread without permission. Max C/I Delay The closer the waiting time of the first packet in the buffer is to the Packet Delay Budget (PDB). HUAWEI TECHNOLOGIES CO. Huawei proprietary. the GBR service with QCI of 1 has a higher priority than other GBR services. PF Relative priority The prioritization of GBR services is different from that of non-GBR services. This factor is added to compare the priority of GBR services with that of non-GBR services. LTD. The UE with better instantaneous channel quality has a higher priority. In the case of the same channel quality.. the higher the priority is.Prioritization of GBR Prioritization of GBR Service Channel quality The instantaneous channel quality of the UE is taken into account. SPI Service Priority Indicator Page 99 . . Page 100 . Huawei proprietary. LTD. No spread without permission.MCS Selection & Resource Allocation HUAWEI TECHNOLOGIES CO. . Huawei proprietary.7. No spread without permission.213 Table7.213 Table 8. you can calculate the throughput for that specific MCS index as follows:  Calculation Procedure for downlink(PDSCH) is as follows :  i) refer to TS36.Calculation of Throughput based on MCS  If you know the MCS index.1.213 Table 7. I_TBS is 21 if MCS is 23)  iii) refer to TS36.1-1  ii) get I_TBS for using MCS value (ex.2.1-1 at step i)  Uplink Analysis Parameter Calculation HUAWEI TECHNOLOGIES CO. it is 51024 bits * 2 Antenna * 1000 ms = about 100 Mbps  Calculation Procedure for uplink(PUSCH) is as follows :  Same as the downlink as above except that you have to refer to 36.1  iv) go to column header indicating the number of RB  v) go to row header ‘21’ which is I_TBS  vi) you would get 51024 (if the number of RB is 100 and I_TBS is 21)  vii) (This is Transfer Block Size per 1 ms for one Antenna)  If we use 2 antenna.6.7. LTD. Page 101 .1. No spread without permission.HUAWEI TECHNOLOGIES CO. LTD.. Page 102 . Huawei proprietary. . etc. Therefore.Thank you www. statements regarding the future financial and operating results. There are a number of factors that could cause actual results and developments to differ materially from those expressed or implied in the predictive statements. Huawei may change the information at any time without notice. such information is provided for reference purpose only and constitutes neither an offer nor an acceptance.huawei. . The information in this document may contain predictive statements including. without limitation. future product portfolio.com Copyright©2011 Huawei Technologies Co. new technology. Ltd. All Rights Reserved.


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