129142407 Lte Radio Procedures

Transcript

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 Frame Structure (FDD) Related Concept 1- Radio Frame 2-Subframe 3-Slot 4- Subcarrier 5- Resource Block (Scheduling Minimum Unit) 6- Resource Element HUAWEI TECHNOLOGIES CO., LTD. Channel RB Subcarrier BW (MHz) 1.4 Number 6 Number 72 3 15 180 5 25 300 10 50 600 15 75 900 20 100 1200 Huawei proprietary. No spread without permission. Page 4 Number of Scheduled User in 1 TTI Scheduling information is in PDCCH frame. 1- Total Number of RE for PDCCH=100(RB for 100Mhz)*12(SC)*3 2- 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.e. (1270-PCFICH-PHICH)/17 ~~ 1000 users approx HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 5 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, 2 * 2 MIMO, 64QAM, the Coding rate is 1. The single cell downlink physical layer theory rate = 50*12*14*(1-(2/21+1/21))*6*2*1000*1 =82.4Mbps 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, RS symbol number=16, 16/168=2/21) 1/21 PDCCH overhead (If downlink sub-frame PDCCH accounted for only a symbol, and the PDCCH symbol is the first symbol of the sub-frame, this is the minimal overhead in PDCCH, a downlink sub-frame occupies 8 subcarriers, so the minimal PDCCH overhead is 8 symbols, 8 / (14 * 12) =8/168= 1/21. 82.4Mbps this is an ideal value, because the SCH, BCH also take up some of the resources, and consider the coding rate, the actual Downlink peak rate around 70Mbps Page 6 HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. 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, None MIMO, 16QAM, the Coding rate is 1. The UE uplink physical layer theory rate = 46*12*14*(1-1/7)*4*1000*1=26.5Mbps 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, and consider the PUCCH occupied 4RB, the pilot overhead is 1/7, the uplink can reach the peak rate 25.6Mbps, in fact should also consider the impact of sounding and PRACH, the uplink peak rate around 25Mpbs HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 7 Carrier Frequency EARFCN Calculation(3GPP : 36.104) Channel raster Table 5.7.3-1 E-UTRA channel numbers The channel raster is 100 kHz for all bands, which means that the carrier centre frequency must be an integer multiple of 100 kHz. 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 - 65535. The relation between EARFCN and the carrier frequency in MHz for the downlink is given by the following equation, where FDL_low and NOffs-DL are given in table 5.7.3-1 and NDL is the downlink EARFCN. FDL = FDL_low + 0.1(NDL – NOffs-DL) The relation between EARFCN carrierequation frequency in MHz for the uplink is given byand the the fo llowing where FUL_low and NOffs-UL are given in table 5.7.3-1 and NUL is the uplink EARFCN. FUL = FUL_low + 0.1(NUL – NOffs-UL) HUAWEI TECHNOLOGIES CO., LTD. E-UTRA Operating Band 1 2 3 4 5 6 7 8 9 10 11 12 13 14 … 17 18 19 20 21 … 33 34 35 36 37 38 39 40 NOTE: FDL_low [MHz] Downlink NOffs-DL Range of N DL 2110 1930 1805 2110 869 875 2620 925 1844.9 2110 1475.9 728 746 758 0 600 1200 1950 2400 2650 2750 3450 3800 4150 4750 5000 5180 5280 599 0 – 600 - 1199 1200 1949 – 1950 2399 – 2649 2400 – 2749 2650 – 2750 3449 – 3799 3450 – 3800 4149– 4150 4749 – 4750 4949– 5179 5000 – 5279 5180 – 5379 5280 – 734 860 875 791 1495.9 5730 5850 6000 6150 6450 5849 5730 – 5999 5850 – 6149 6000 – 6150 - 6449 6450 6599– FUL_low [MHz] 1920 Range of N UL 18000 1850 1710 1710 824 830 2500 880 1749.9 1710 1427.9 698 777 788 704 815 830 18000 – 18599 18600 18600 – 19199 19200 19200 – 19949 19950 19950 – 20399 20400 20400 – 20649 20650 20650 – 20749 20750 20750 – 21449 21450 21450 – 21799 21800 21800 – 22149 22150 22150 – 22749 22750 22750 – 22949 23000 23000 – 23179 23180 23180 – 23279 23280 23280 – 23379 23730 23850 24000 832 1447.9 Uplink NOffs-UL 23730 – 23849 23850 – 23999 24000 – 24149 24150 24150 - 24449 24450 24450 – 24599 1900 36000 36000 36199 – 1900 36000 36000 – 36199 2010 36200 36200 36349 – 2010 36200 36200 – 36349 1850 36350 36350 36949 – 1850 36350 36350 – 36949 1930 36950 36950 37549 – 1930 36950 36950 – 37549 1910 37550 37550 37749 – 1910 37550 37550 – 37749 2570 37750 37750 38249 – 2570 37750 37750 – 38249 1880 38250 38250 38649 – 1880 38250 38250 – 38649 2300 38650 38650 39649 – 2300 38650 38650 – 39649 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. This implies that the first 7, 15, 25, 50, 75 and 100 channel numbers at the lower operating band edge and the last 6, 14, 24, 49, 74 and 99 channel numbers at the upper operating band edge shall not be used for channel bandwidths of 1.4, 3, 5, 10, 15 and 20 MHz respectively. Huawei proprietary. No spread without permission. Page 8 Example FDL (center Freq) = FDL_low + 0.1(NDL (EARFCN) – NOffs-DL) Or NDL (EARFCN)= 10*(FDL (center Freq) - F DL_low ) + NOffs-DL Say FDL (center Freq) = 1815 NDL (EARFCN)=10*(1815-1805)+1200 NDL (EARFCN)=1300 HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 9 IDLE Mode Behavior Idle Mode Overview PLMN Selection Cell selection & cell reselection System Information reception Tracking area registration Paging monitoring procedure HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 10 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 Cell Selection Criteria  During cell selection, a UE needs to check whether a cell fulfills the cell selection criteria. The cell selection is based on the RSRP of the E-UTRAN cell. Before a UE can select a cell to camp on, the RSRP of the cell must be higher than the user-defined minimum receive (RX) level Qrxlevmin of the cell.  The formula for cell selection decision is as follows:  Srxlev > 0  where Srxlev = Qrxlevmeas - (Qrxlevmin + Qrxlevminoffset) - Pcompensation  is the measured RX level in the cell (RSRP), expressed in decibels with reference to one milliwatt (dBm).  Qrxlevmeas  Qrxlevmin  Qrxlevminoffset is the minimum required RX level (set in the eNodeB) in the cell, expressed in units of dBm. Qrxlevmin is the offset to . This offset is taken into account when the UE attempts to camp on a cell in a higher-priority PLMN. That is, when camped on a cell in a VPLMN, the UE considers this offset parameter, which was signaled from the associated cell in the higher-priority PLMN, Srxlev in the evaluation.  Pcompensation is generated according to the function max(PMax - UE Maximum Output Power, 0). The value is expressed in decibels (dB).  PMax is the maximum allowed transmit power of the UE in the cell, expressed in units of dBm. It is used in uplink transmission. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 14 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.  Cell reselection process:  Measurement Start criteria  Cell reselection criteria Intra frequency Interfrequency (within LTE) InterRAT ( LTE to Other RAT) HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 15 Intra frequency Measurement  If the intra f requency measurement triggering threshold is not configured, the UE performs intra frequency measurements always.  If the intra frequency measurement triggering threshold is configured:  Srxlev > SintraSearch,   the UE does not perform intra frequency measurement. Srxlev <= SintraSearch,  the UE perform intra frequency measurement. Srxlev = Smeas - SMin HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 16 Inter Frequency // RAT Measurement  For the neighbor wi th higher priority   The UE always perform inter frequency / RAT measurement For the neighbor with Low or equal priority  If the threshold is not configured , the UE always perform inter frequency/RAT measurement  If threshold is configured:  When Srxlev > SNonIntraSearch, UE does not perform inter frequency / RAT measurement  When Srxlev <=SNonIntraSeach, UE perform inter frequency / RAT measurement From SIB, UE can get t he serving cell & inter frequency / RAT neighbors’ priority For the high priority cells, UE measure them always, for low priority cells, UE measure them incase of serving cell signal is lower Than threshold. The intra frequency cells have the same frequency priority, frequencies of different RATs must have different priorities HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 17 Intra Frequency//Same Priority Cell Reselection Decision  A UE makes a cell reselection decision according to cell reselection criteria. When making a decision on reselection to an in trafrequency or equal-priority inter-frequency cell, the UE checks whether the signal quality of a neighboring cell is higher than that of the serving cell. The UE evaluates the neighboring cell only after the cell meets the cell selection criteria.  The cell-ranking criteria R_s for the serving cell and R_n for neighboring cells are defined as follows:   R_s = Qmeas,s + Qhyst R_n = Qmeas,n - CellQoffset  where:  Qmeas,s is the measured RSRP of the serving cell, expressed in units of dBm.  Qhyst is the hysteresis for the serving cell used in the ranking criteria, expressed in units of dB. It is set in the eNodeB.  Qmeas,n is the measured RSRP of the neighboring cell, expressed in units of dBm.  CellQoffset is the offset for the neighboring cell used in the ranking criteria, expressed in units of dB. It is set in the eNodeB.  According to the cell reselection criteria, 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.  More than one second has elapsed since the UE camped on the serving cell.  During cell reselection, the UE needs to check whether access to that cell is allowed according cellAccessRelatedInfo to the Information Element (IE) in the SIB1. If the cell is barred, it must be excluded from the candidate list, and the UE does not consider the cell as a candidate for cell reselection. If the cell is unsuitable because it is part of the list of forbidden TAs for roaming or it d oes not belong to the registered PLMN or an EPLMN, the UE does not consider this cell and other cells on the same frequency as candidates for reselection for a maximum of 300 seconds. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 18 Inter-RAT/Inter Frequency High Priority Cell Reselection Decision  For the high priority cells, the UE perform cell reselection if following conditions are met:   In “ reselection time”, “Sxlev” of a neighbor is higher than “ ThreshXHigh”  More than one second has elapsed since the UE camped on the serving cell. 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, the UE does not consider this cell as candidate for reselection for a maximum of 300 seconds. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 19 Inter-RAT/Inter-Frequency low Priority Cell Reselection Decision  For low priority cells, 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”, 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. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 20 System Information Block Contents SI Block MIB Content Downlink bandwidth of a cell , Physical HARQ Indication Channel (PHICH) parameters, and System Frame Number (SFN) SIB1 SIB2 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 SIB3 SIB4 Common cell reselection parameters for all the cells and intra-frequency cell reselection parameters Intra-frequency neighboring cell list, reselection parameters of each neighboring cell used for cell reselection, 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 GERAN neighboring EARFCN list and reselection parameters of each EARFCN used for cell reselection SIB8 CDMA2000 pre-registration information CDMA2000 neighboring frequency band list and reselection parameters of each band used for cell reselection CDMA2000 neighboring cell list of neighboring frequency band SIB9 SIB10 SIB11 Name of the home eNodeB Earthquake and Tsunami Warning System (ETWS) primary notif ication ETWS secondary notification HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 21 MIB i) MIB is transmitted at a fixed cycles (every 4 frames starting from SFN 0) HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 22 System Information Type-1 1- MCC/MNC 2- Tracking area code: TAC 3- Cell identity Scheduling information of other SIBs i) SIB1 is also transmitted at the fixed cycles (every 8 frames starting from SFN 0). SIB1 Parameters related to cell access and cell selection and scheduling information of SI messages HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 23 System Information (Sib-3) SIB3 HUAWEI TECHNOLOGIES CO., LTD. Common cell reselection parameters for all the cells and intra-frequency cell reselection parameters Huawei proprietary. No spread without permission. Page 24 System Information(Sib-4//Sib-6) SIB6 SIB4 Intra-frequency neighboring cell list, reselection parameters of each neighboring cell used for cell reselection, and intrafrequency cell reselection blacklist HUAWEI TECHNOLOGIES CO., LTD. UMTS Terrestrial Radio Access (UTRA) Frequency Division Duplex (FDD) neighboring EARFCN list and reselection parameters of each EARFCN used for cell reselection Huawei proprietary. No spread without permission. UTRA Time Division Duplex (TDD) neighboring EARFCN list and reselection parameters of each EARFCN used for cell reselection Page 25 Tracking Area Registration EPC send paging messages to all enodeB in the TA. A TA is identified by Tracking area identifier (TAI), which consist of MCC+MNC+TAC  TA in SIB1:  A UE informs the EPC of its Tracking area in 2 ways.  Attach/Detach  TA update (Periodic + Normal) HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 26 Attach//Detach  When a UE needs to obtain service from a network but is not registered to the network, 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, a detach procedure is initiated. After t he detach procedure, EPC no longer pages the UE. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 27 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., LTD. Huawei proprietary. No spread without permission. Page 28 Paging Monitoring Procedure Key Concept 1- DefaultPagingCycle (T), DRX Cycle Coefficient. 2- Paging Frame (PF) Function of IMSI 3- Paging Occasion (PO) Paging Parameters in SIB2 SFN for PF SFN mod T = (T div N) x (UE_ID mod N) BCCH-DL-SCH-Message ::= SEQUENCE +-message ::= CHOICE [c1] +-c1 ::= CHOICE [ systemInformation] 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. * Paging Frame (PF) is one Radio Frame, which may contain one or multiple Paging Occasion(s). HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. +-systemInformation ::= SEQUENCE +-criticalExtensions ::= CHOICE [ systemInformation-r8] +-systemInformation-r8 ::= SEQUENCE [0] +-sib-TypeAndInfo ::= SEQUENCE OF SIZE(1..maxSIB[32]) [1] | +- ::= CHOICE [sib2] | +-sib2 ::= SEQUENCE [00] ...... | | +-pcch-Config ::= SEQUENCE | | | +-defaultPagingCycle ::= ENUMERATED [rf128] | | | +-nB ::= ENUMERATED [oneT] Page 29 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,NB). The NB parameter specifies the number of PO subframes in a DRX cycle. Based on the actual configuration on the eNodeB, NB can be set to 4T, 2T, T, T/2, T/4, T/8, T/16, or T/32. Ns =max(1,NB/T). UE_ID is IMSI mod 1024. SIB-2 HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 30 Understanding of NB HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 31 SFN for PF SFN mod T = (T div N) x (UE_ID mod N) Example IMSI: IMSI(448835805669362) N=N is min(T,NB)  N=min(T,T) T=128 Ns =max(1,NB/T)  Ns=max(1,NB/T) Ns=max(1,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(7.890625) mod 1=7 mod 1= 0 0 1 2 3 4 5 6 7 8 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 9 PO HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 32 Connected Mode HUAWEI TECHNOLOGIES CO., LTD.  Handover  Power Control (DL)  Scheduling (DL) Huawei proprietary. No spread without permission. Page 33 Handover Procedure Mobility Management Overview Intra Frequency handover Inter Frequency handover Inter RAT handover HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 34 Mobility Management Overview HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 35 Handover Procedures Entities mobility robust optimization (MRO) HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 36 Measurement Triggering Only voice HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 37 Handover Events HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 38 Key Concept RRC Connection Reconfiguration is use to Modify/establish/release RB/to perform Handover, to setup/modify/release measurement Main IE: Measurementconfiguration Mobilitycontrolinformation Nas-DedicatedInformation RadioResourceConfiguration Securityconfiguration Ue-RelatedInformation HUAWEI TECHNOLOGIES CO., LTD. Step Direction Message 1 UE <---> SS < Power On and Registration > Cell 1 2 UE <---> SS < Now UE is in IDLE mode > Cell 1 3 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 <--- SS Security Mode Command Cell 1 8 UE ---> SS Security Mode Complete Cell 1 9 UE <--- SS RRC Connection Reconfiguration Cell 1 10 UE ---> SS RRCConnectionReconfigurationComplete Cell 1 11 UE <--- SS RRC Connection Reconfiguration Cell 1 12 UE ---> SS RRCConnectionReconfigurationComplete Cell 1 13 UE ---> SS Measurement Report Cell 1 14 UE <--- SS RRC Connection Reconfiguration Cell 1 15 UE ---> SS PRACH Cell 2 16 UE <--- SS RACH Response Cell 2 17 UE ---> SS RRCConnectionReconfigurationComplete Cell 2 18 UE <--- SS ueCapabilityEnquiry Cell 2 19 UE ---> SS ueCapabilityInformation Cell 2 20 UE ---> SS ulInformationTransfer + Detach Request Cell 2 21 UE <--- SS RRC Connection Release Cell 2 Huawei proprietary. No spread without permission. Page 39 Target Cell Memo reactivating default EPS Bearer Measurement Control for Target Cell Handover Command PASS/FAIL Gap Mode A measurement gap is a time period during which the UE performs measurements on a neighboring frequency of the serving frequency. Measurement gaps are applicable to interfrequency and inter-RAT measurements. The UE performs inter-frequency or inter-RAT measurements only within the measurement gaps. One UE normally has only one receiver, and consequently one UE can receive the signals on only one frequency at a time. When inter-frequency or inter-RAT measurements are triggered, the eNodeB delivers the measurement gap configuration, and then the UE starts gap-assisted measurements accordingly. As shown above, Tperiod denotes the repetition period of measurement gaps, and TGAP denotes the gap width, within which the UE performs measurements HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 40 Intra-Frequency handover Event A3 will be trigger for Intra-frequency handover. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 41 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. Huawei proprietary. No spread without permission. Page 42 HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 43 HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 44 The data forwarding process is as follows: After the source eNodeB sends a handover command to the UE, the UE detaches the connection from the source eNodeB. The source eNodeB then forwards the uplink (UL) data that is received out of order and the DL data to be transmitted, 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. Intra-eNodeB handovershandover, do not require data forwarding. In the case of inter-eNodeB the source eNodeB selects a data forwarding path by using the X2/S1 adaptation mechanism. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 45 When a handover fails, the UE performs a cell selection procedure and then initiates a procedure of RRC connection reestablishment towards the selected cell. The eNodeB makes a decision based on whether the context of the UE is present or not. If the eNodeB accepts the re-establishment request, the UE accesses the selected cell, thus avoiding drop of the call caused by the handover failure. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 46 Inter-Frequency Measurement HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 47 Event A2 Triggering Algorithm In a coverage-based inter-frequency handover, event A2 triggers inter-frequency measurements. The triggering of this event indicates that the signal quality in the serving cell is lower than a specified threshold. Ms: The measurement result of the serving cell Hys: The hysteresis for event A2 Thresh: The threshold for event A2, it can be defined separately with RSRP or RSRQ HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 48 Event A1 Stop Algorithm Ms: The measurement result of the serving cell Hys: The hysteresis for event A1 HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 49 Event A4 Handover Execution Mn: The measurement result of the neighboring cell. Ofn: The frequency-specific offset for the frequency of the neighboring cell. Ocn: The cell-specific offset for the neighboring cell. Hys: The hysteresis for event A4 Thresh: The threshold for event A4 HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 50 Inter-RAT Measurement Measurement Trigger HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 51 Measurement Object HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. 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. The hysteresis values for inter-RAT handovers to UTRAN, HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 53 LTE UMTS PS Handover Flow HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 54 Power Control HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 55 Classification of Power Control HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 56 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, synchronization signal, PBCH, PCFICH, and the PDCCH and PDSCH that carry common information of the cell. Users configure fixed power based on channel quality. The configured power must meet the requirements for the downlink coverage of the cell . Dynamic power control Dynamic power control is applicable to the PHICH and the PDCCH and PDSCH that carry dedicated information sent to UEs. Dynamic power control lowers interference, expands cell capacity, and increases coverage while meeting users' QoS requirements. However, these channels can also support fix power assignment, and in fact, this is our recommendation because the AMC function can also meet the requirement of QoS. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 57 Cell Specific RS Power Setting The cell-specific reference signal is transmitted in all downlink subframes. The signal serves as a basis for downlink channel estimation, which is used for data demodulation. The power for the cell-specific reference signal is set through the ReferenceSignalPwr parameter, which indicates the Energy Per Resource Element (EPRE) of the cell-specific reference signal. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 58 Synchronization Signal Power Setting The synchronization signal is used for cell search and system synchronization. There are two types of synchronization signals, 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 TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 59 PBCH/PCFICH Power Setting On the PBCH, broadcast messages are sent in each frame. The messages carry the basic system information of the cell, such as the cell bandwidth, antenna configuration, and frame number. The offset of the power for the PBCH against the power for the cell-specific reference signal is set through the PbchPwr parameter. 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. The power for the PCFICH is set through the PcfichPwr parameter, which indicates an offset of the power for the PCFICH against the power for the cell-specific reference signal. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 60 PDCCH/PDSCH Power Setting HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 61 Dynamic Power Control - PHICH HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 62 Dynamic Power Control - PDCCH When PDCCH carry the following dedicate info, 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. Huawei proprietary. No spread without permission. Page 63 PDSCH Power Presentation Regarding power control for the PDSCH, the OFDM symbols on one slot can be classified into two types. 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. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 64 Automatic Neighbor Relation ANR is a self-optimization function. It automatically maintains the integrity and effectiveness of neighbor cell lists (NCLs) to increase handover success rates and improve network performance. In addition, ANR does not require manual intervention, which reduces the costs of network planning and optimization. Neighbor relations are classified into normal and abnormal neighbor relations. Abnormal neighbor relations exist in the cases of missing neighboring cells, unstable neighbor relations, PCI collisions, and abnormal neighboring cell coverage. ANR automatically detects missing neighboring cells, PCI collisions, and abnormal neighboring cell coverage and maintains neighbor relations. ANR classifications HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 65 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. Huawei proprietary. No spread without permission. Page 66 NCL  An NCL of a cell contains the information about the neighboring cells of a cell. Unless otherwise stated, neighboring cells mentioned in this document exclude intra-eNodeB neighboring cells. NCLs are classified into intra-RAT NCLs and inter-RAT NCLs. Each cell has one intra-RAT NCL and multiple inter-RAT NCLs.  An NCL includes the ECGIs (for E-UTRAN cells) or CGIs (for inter-RAT cells), PCIs, and EARFCNs of the neighboring cells.  The eNodeB adds newly detected neighboring cells to the NCL. The NCL is used as a basis for creating neighbor relations. Neighboring cells in the NCL can be automatically managed (for example, added, deleted, or modified) by ANR. They can also be managed manually. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 67 NRT An NRT of a cell contains the information about the neighbor relations between a cell and its neighboring cell NRTs are classified into intra-RAT NRTs and inter-RAT NRTs. Each cell has one intra-RAT intra-frequency N one intra-RAT inter-frequency NRT, and multiple inter-RAT NRTs. The intra-RAT intra-frequency NRT and intr intra-frequency NRT are referred to as the intra-RAT NRT in this document. shows an example of the NRT. The information in this table is for reference only. Table 3-1 An example of the NRT HUAWEI TECHNOLOGIES CO., LTD. SN LCI Local Cell PLMN TCI No Remove 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. No HO Page 68 TempNRT A TempNRT is a temporary NRT. It has the same data structure as the NRT. 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 Intra-RAT intrafrequency TempNRT and intra-RAT intra-frequency TempNRT are referred to as the intra-RAT TempNRT in this document. After detecting a new intra-RAT neighbor relation, the eNodeB adds it to the intra-RAT TempNRT. Then, the eNodeB regularly maintains the neighbor relation in the TempNRT. If the new neighbor relation is normal, the eNodeB adds it to the intra-RAT NRT. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 69 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. 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 Blacklist An X2 blacklist contains the information about an eNodeB and its neighboring eNodeBs. X2 interfaces cannot be set up automatically between the eNodeB and the neighboring eNodeBs. If an X2 interface has been set up, it will be removed automatically. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 70 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. 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. 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. Huawei proprietary. No spread without permission. Page 71 PCI A PCI is the identifier of a physical cell. A maximum of 504 PCIs are supported, according to reference document. Therefore, PCI collisions occur inevitably. PCI collisions negatively affect handover performance and the handover success rate. For details about PCI collision handling, 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., LTD. Huawei proprietary. No spread without permission. Page 72 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. The eNodeB regards this cell as a neighboring cell of the serving cell and therefore attempts to add the neighbor relation to the NRT,. The signals of an abnormal neighboring cell are generally unstable and therefore the success rate of handovers to this cell is low. 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. l In mountains, the signals of the umbrella cell cover lower cells. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 73 Classification of ANR  Intra-RAT ANR  Intra-RAT Fast ANR  Inter-RAT ANR  Inter-RAT Fast ANR HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 74 Intra-RAT ANR 1. 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. Source 2. The UE detects that the PCI of cell B meets the measurement configuration and reports it to the source eNodeB. Then, the source eNodeB checks whether the intraRAT NCL of cell A includes the PCI of cell B. If yes, the procedure ends. If no, the following steps continue. 3. The source eNodeB instructs the UE, using the newly discovered PCI as a parameter, to read the ECGI, Tracking Area Code (TAC), and PLMN ID list of cell B. 4. The source eNodeB schedules appropriate idle periods to allow the UE to read the ECGI, TAC, and PLMN ID list of cell B over the broadcast channel (BCH). 5. The UE reports the detected ECGI, TAC, and PLMN ID list of cell B 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., LTD. Huawei proprietary. No spread without permission. Page 75 Neighbor Intra-RAT Fast ANR Before a UE performs handovers, 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. This reduces the impact of event-triggered UE measurements on handover performance when the UE performs handovers. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 76 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; therefore, intra-cell interference is very low. However, inter-cell interference is relatively high because the frequency reuse factor is 1, in which case every cell can provide services over the entire system band. For cell edge users (CEUs), the impact of the inter-cell interference is especially severe. Therefore, to increase the cell capacity and CEU throughput, inter-cell interference must be mitigated. 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. ICIC divides the entire system band into three frequency bands and uses different frequency bands at the edge of neighboring cells. CEUs, which cause high interference or may be sensitive to interference, are preferentially scheduled in the cell edge bands to mitigate inter-cell interference. The interference mitigation enhances the network coverage and improves the CEU throughput HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 80 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. ii) Edge band mode assignment is a technique of allocating different edge bands to neighboring cells. 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. Edge band mode assignment and edge band adjustment collaborate to determine the edge band of each cell. iii) Power control and MAC scheduling collaborate to allocate PRBs to UEs based on cell edge bands and UE types. PRBs in edge bands are mainly allocated to CEUs, and those in center bands are mainly allocated to CCUs. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 81 CEU/CCU Identification Principles When initially accessing a network, a UE is recognized as a CCU by the serving cell; after a handover, the UE is recognized as a CEU by the target cell. After a short period following the initial access or handover, 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. 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 eNodeB treats the UE as a CCU. An example of this is when the UE moves from the cell edge to the cell center. ii) If an ICIC event A3 report contains the measurement result about at least one neighboring cell, the eNodeB treats the UE as a CEU. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 82 ICIC Event A3 Based on RSRP Measurement HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 83 Entering Condition for ICIC Event A3 HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 84 Leaving Condition for ICIC Event A3 HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 85 More Parameter of ICIC Event A3 HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 86 Edge Band Mode Assignment Edge band mode assignment is a technique of allocating different edge bands to neighboring cells. There are three edge band modes: MODE1, MODE2, and MODE3, whichrepresent low-, medium-, and high-frequency bands, respectively. The bandwidth of each band is about 1/3 of the physical downlink shared channel (PDSCH) or physical uplink shared channel (PUSCH) bandwidth. The PRBs available to CEUs in a cell using a specific edge band mode correlate with the ICIC policy and system bandwidth. The policy can be either dynamic ICIC or static ICIC. If there are three cells per eNodeB, as shown in Figure 3-2, neighboring cells use different edge band modes so that CEUs in the cells are served by different frequency bands in the system band. Theoretically, the use of three edge band modes can eliminate inter-cell interference in the frequency domain. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 87 Edge Band Adjustment (Only in Dynamic ICIC) There are two ICIC policies: static ICIC and dynamic ICIC. The difference between them is that only dynamic ICIC adjusts edge bands. 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. Figure is used as an example to describe edge load evaluation: Yellow grids for the current cell represent the PRBs defined in static 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. In this situation, 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. The edge load of the current cell is high while the edge load of the neighboring cell is low. ii) Edge band shrinking condition − Active shrinking: The current cell actively shrinks its edge band if its edge load is relatively low. − Passive shrinking: When the neighboring cell expands its actual edge band within the edge band defined in static ICIC, the current cell shrinks its edge band if the PRBs used by the current and neighboring cells collide. Figure shows an example of passive shrinking. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 88 Scheduling The eNodeB implements scheduling at the media access control (MAC) layer and provides time-frequency resources for uplink and downlink through scheduling. On the premise of guaranteed quality of service (QoS), 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., LTD. Huawei proprietary. No spread without permission. Page 89 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. RR None Each UE has equal opportunity to be scheduled. To verify the upper limit of The UE with a small ratio between the service rate and channel quality has a higher priority in scheduling. scheduling fairness To verify the system throughput and fairness PF Service rate and channel quality EPF Service rate, channel quality, and QoS requirement HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Usage Scenario To verify the maximum system throughput In operating networks Page 90 Scheduling Scheme  Semi Persistent  Dynamic Semi-Persistent Scheduling Semi-persistent scheduling is introduced to reduce the overhead of control signaling. 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, regular packet arrival, and low delay requirements, such as the Voice over IP (VoIP). By adopting semipersistent scheduling, VoIP services can save the overhead of control signaling and increase the VoIP capacity. Dynamic Scheduling In dynamic scheduling, 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. Dynamic scheduling has no requirements on the size and arrival time of data packets. Therefore, dynamic scheduling is applicable for all services. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 91 DL Scheduler Downlink scheduling allocates time-and-frequency resources at the Physical Downlink Shared Channel (PDSCH) for transmission of system messages and downlink data. Downlink scheduling described in this chapter is based on the EPF scheduling strategy. Downlink scheduling calculates available scheduling resources based on the current remaining power. In addition, the scheduling priority and Modulation and Coding Scheme (MCS) are determined based on the amount of data at the Radio Link Control (RLC) layer, QoS requirements of bearers, and UE channel quality. In downlink scheduling, 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. Therefore, if reported CQIs cannot properly reflect the actual channel conditions, the downlink resource efficiency is low. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 92 DL Scheduling VoIP service The VoIP service experiencing semi-persistent scheduling has the highest priority. Semi-persistent scheduling is used in the talk spurts of the VoIP services. Control-plane data and IMS signaling Control-plane data consists of common control messages and UE-level control messages. Common control messages consist of broadcast messages, paging messages, and random access response messages. UE-level control messages consist of Signaling Radio Bearer 0 (SRB0), SRB1, and SRB2. The scheduling of IMS signaling is the same as that of UE-level control messages. 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. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 93 VOIP HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 94 Control-Plane Data and IMS Signaling The scheduling priority of control-plane data is only lower than that of VoIP services. Control-plane data is subject to dynamic scheduling. Control-plane data consists of common control messages and UE-level control messages. The scheduling of IMS signaling is the same as that of UE-level control messages. Handover and Power control is also UELevel Control messages. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 95 HAQR Retransmission Data HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 96 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 l inks 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., LTD. Huawei proprietary. No spread without permission. Page 97 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. 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. The UE with a higher level set by operators has a higher priority in scheduling. 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. Huawei eNodeB can distinguish between Bit Torrent (BT) and non-BT services using a switch under the DlSchSwitch parameter. Larger weight factor leads to higher priority of scheduling HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. SPI Service Priority Indicator Max C/I + PF+ARP+SPI=ePF Page 98 Prioritization of GBR Prioritization of GBR Service Channel quality The instantaneous channel quality of the UE is taken into account. The UE with better instantaneous channel quality has a higher priority. In the case of the same channel quality, the GBR service with QCI of 1 has a higher priority than other GBR services. Max C/I Delay The closer the waiting time of the first packet in the buffer is to the Packet Delay Budget (PDB), the higher the priority is. The PDB value depends on the QCI. 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. HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. SPI Service Priority Indicator Page 99 MCS Selection & Resource Allocation HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 100 Calculation of Throughput based on MCS  If you know the MCS index, you can calculate the throughput for that specific MCS index as follows:  Calculation Procedure for downlink(PDSCH) is as follows :  i) refer to TS36.213 Table 7.1.7.1-1  ii) get I_TBS for using MCS value (ex, I_TBS is 21 if MCS is 23)  iii) refer to TS36.213 Table7.1.7.2.1  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, 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 36.213 Table 8.6.1-1 at step i)  Uplink Analysis Parameter Calculation HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 101 HUAWEI TECHNOLOGIES CO., LTD. Huawei proprietary. No spread without permission. Page 102 Thank you www.huawei.com Copyright©2011 Huawei Technologies Co., Ltd. All Rights Reserved. The information in this document may contain predictive statements including, without limitation, statements regarding the future financial and operating results, future product portfolio, new technology, etc. 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. Therefore, such information is provided for reference purpose only and constitutes neither an offer nor an acceptance. Huawei may change the information at any time without notice.