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1、LTE Basic Introduction,Part IMobile Technology OverviewPart IILTE Features&PerformancePart IIINetwork Evolution&Product Strategy,3,Evolution TrendLow costIP trendBroadbandMulti-frequency,Mobile Technology Evolution,4,802.16m,Completion date:LTE,expected Sept.2008;UMB,Apr.2007;16e,Dec.2005;16m,expect
2、ed Q3 2009,WiMAX:immature;LTE and UMB:in planning,16e have trial deployments,LTE/UMB commercialization expected 2010 or later,No Commercial launch,16e products will be available soon,LTE/UMB have prototypes now.,802.16e,UMB,Standard maturity,Product Status,Chipset maturity,Network status,Deployment
3、status,LTE,The Status of LTE/UMB/WiMAX,5,HSPA,LTE,Basic feature,Performance(Data rate),Standard,UMB,FDDDL/UL:OFDMA/OFDMA or CDMAMIMO64QAMBW:1.25/2.5/5/10/20 MHz,DL:288Mbps(20MHz,4*4)UL:75Mbps(20MHz,1*2),Ratified in Apr.2007,Cost of the IPR and terminal,High IPR rateresults in high price of the termi
4、nal.,IPR Pooling willmake the price of the terminal lower.,NGMN to find solution for reducing IPR Cost,Held by Qualcomm,Technical Comparison HSPA/WiMAX/LTE/UMB,6,WiMAX was developed with the main objective to offer IP based broadband internet services as wireless DSL.Both WiMAX and LTE have adopted
5、OFDM technology for downlink,but different technology for uplink.LTE is tailored for handheld terminals with careful consideration on the power consumption.LTE is the evolution of mainstream 3G networks.WiMAX has recently developed the eco-system.WiMAX is facing more spectrum challenges than LTE,bec
6、ause no unified spectrum is available for WiMAX Scattered and isolated TDD spectrum available for WiMAX(2.3,3.5 GHz)WiMAX operators with adjacent bands need to be fully coordinated(out of regulators jurisdiction),or need more guard bands.,Viewpoints on LTE&WiMAX,7,LTE Standardization Progress,8,ZTE
7、Research Focus on LTE Standardization,Architecture&MigrationMulti-Vendor RAN&SONRandom AccessChannel CodingResource AllocationMIMOInter-cell Interference CoordinationIntra-LTE MMInter-RAT MMRRMMBMSHNB Access ControlLTE-CDMA-WiMAX Inter-working,Part IMobile Technology OverviewPart IILTE Features&Perf
8、ormancePart IIINetwork Evolution&Product Strategy,10,LTE,Long Term Evolution for Next Decade,LTE Targets,11,System Architecture Evolution,12,PS domain based CN:MME/S-GW Single node RAN:eNode B,Flat Architecture,LTE Network Architecture,13,EPS Bearer Service Architecture,Base of QoS,14,LTE Functional
9、 Split,15,RNC,Node B,eNode B,Iu Interface,S1 Interface,Iur Interface,X2 Interface,Iub Interface,Internal Interface,eNode B Functionality,16,S1&X2 Interface IP Based,S1/X2 Interface U-plane,S1/X2 Interface C-plane,17,LTE Radio Interface User Plane,Same structure as UMTS for PS domain,18,LTE Radio Int
10、erface Control Plane,PDCP for signaling ciphering&integrity protection,19,LTE RRC State,Simplified RRC states,20,UE Identity,E-UTRAN Related,C-RNTI:Unique UE identification at the cell level identifying RRC ConnectionUsed for scheduling unless the cost would turn out to be too high and the introduct
11、ion of a separate MAC identity would be requiredRandom value for contention resolution:Temporarily identified for contention resolution purposes during some transient states,21,Network Entity Related Identity,MME identity:During RRC connection setup,provided by the UE to the eNB in order for the eNB
12、 to fetch the UE context from the MMEWithin the S-TMSI,to ensure that the S-TMSI remains unique in a tracking area shared by multiple MMEs.eNB identity or cell identity(FFS):For the new eNB to obtain a UE context from the old eNBTracking Area identity(TAI):Constructed from the MCC,MNC and TACPhysica
13、l layer cell identity:504 unique physical-layer cell identities,168 groups,each containing 3,22,LTE Transport Channel&Physical Channel,Downlink mapping Physical Channel:PBCH,PDSCH,PMCH,CFICH,PDCCH,PHICH,Uplink mapping,23,Uplink mapping,Downlink mapping,LTE Logical Channel&Transport Channel,24,Large
14、bandwidth and bandwidth flexibilityWith bandwidth increases,the OFDMA signal remains orthogonal while CDMA performance suffers due to increased multi-path components.Dealing with different bandwidths in the same system is more flexible with OFDMA.Flat architectureWhen packet scheduling is located in
15、 the base station,fast scheduling,including frequency domain scheduling,can be applied to improve cell capacity.Frequency domain scheduling can be done in OFDMA but not in CDMA.Amplifier friendly uplink solutionLower PAPR is achieved with SC-FDMA than OFDMA,which enables better power amplifier effic
16、iency in the terminal.Simpler multi-antenna operationMIMO is simpler to implement with OFDMA than with CDMA.,Why is OFDMA/SC-FDMA?,25,OFDM,26,OFDMA/SC-FDMA,27,Frequency Bands,28,Channel Bandwidth,29,Generic Frame Structure,TTI:1ms,30,Basic Transmission Scheme,Sub-carrier spacing f:15 kHz Resource bl
17、ock:12 consecutive sub-carriers during one slot OFDM symbols per slot:7 or 6,with normal or extended cyclic prefix Reduced sub-carrier spacing:7.5 kHz,only in downlink for MBMS dedicated cell,31,PBCH and Synchronization Signal Overhead,Control&sync channel,only 1 out of 10 sub-frame contains PSCH/SS
18、CH(signal)/PBCH(10M example 2 Ctl.Symb.),Control&sync channel,only 1 out of 10 sub-frame contains PSCH/SSCH(signal)/PBCH(1.4M example 2 Ctl.Symb.),32,Reference Signal at 1,2,4 TX,33,Spectrum Efficiency Principle,The number of RB is not linear to the bandwidth,such as,6 RB for 1.4M,25 RB for 5M,which
19、 contributes a lot to the efficiency difference.The total number of OFDM symbol is linear to the RB number.The PDCCH,PHICH,and PCFICH are linear to the RB number,taking fixed N slots per sub-frame in each RB(N=1,2,or 3,indicated by PCFICH,normally 2).The PSCH,SSCH,and PBCH are not linear to the RB n
20、umber,taking fixed 8 slots per frame(not sub-frame),i.e.fixed 576 RE.The reference signal(RS)is linear to bandwidth,1 TX taking 8/(12*14)resource,2 TX taking 16/(12*14)resource,4 TX taking 24/(12*14)resource.,34,Spectrum Efficiency Calculation,35,MIMO in LTE,Basic antenna configuration:2*2 downlink,
21、1*2 uplinkMaximum antenna configuration:4*4,36,Data,DeMUX,Space multiplexing&space diversity leads to higher bit rate.,MIMO Principle,37,ICIC(Inter-Cell Interference Coordination)Radio resource management(notably the radio resource blocks)to keep inter-cell interference under control SONSelf Organiz
22、ation Network MBSFNMBMS Single Frequency Network Multi-vendor RANCoordination of the eNode B from multiple vendors within one area,LTE Special Features,38,SON in NGMN,39,Current focus on:Planning of transport parameters of a new eNode B Hardware installation Network authentication Software installat
23、ion,SON in 3GPP,40,Self Configuration,Self installation Self upgrade eNode B location eNode B radio parameters(RP)eNode B transport parameters(TP)Network security:Node security,automatic connection to the network,SON Features,41,Self Optimization,Self Healing,Optimization of radio parameters,e.g.nei
24、ghboring cell list Optimization of transport parameters Power saving,Information correlation for fault management Automatically realized alarm management functions,such as alarm report,alarm acknowledge,some simple operation(reset or block)Compensation for outage of higher level network elements Fas
25、t recovery of EMS,SON Features,42,MBMS Definition,MBSFN operation is possible in both MBMS dedicated cell and Unicast/MBMS mixed cell.MBMS reception is possible for UEs in RRC_CONNECTED or RRC_IDLE states.,43,Peak Bit Rate,With 4*4 MIMO,the theoretical peak rate will reach 340 Mbps.,44,VoIP Capacity
26、 Evaluation,VoIP capacity for E-UTRA(AMR 12.2 Kbps,5%outage),Source:3GPP TR 25.814 V7.1.0(2006-09),Downlink,Uplink,45,U-plane Latency Evaluation,Based on the adopted protocol architecture for LTE with no HARQ retransmissions a delay of 3.3 ms is seen achievable.This delay is based on an unloaded sys
27、tem with a zero-sized payload scenario and hence the delay contributions from scheduling and packet lengths are ignored.An average delay of 4.0 ms is achievable given the additional delay from HARQ retransmissions occurring only for 30%of first packet transmissions when using an N=5 stop-and-wait pr
28、otocol.,Part IMobile Technology OverviewPart IILTE Features&PerformancePart IIINetwork Evolution&Product Strategy,47,GSM for speechWCDMA for speech,low or medium rate packetLTE for high rate packet,Network Co-existence Case,48,LTE Mobility Management,49,Service Continuity:E-UTRAN&3GPP2 Access,Bidire
29、ctional service continuity between cdma2000 1xRTT Revision A and E-UTRAN If bi-directional support is not practical,service continuity from E-UTRAN to cdma2000 1xRTT Revision A should have the higher priority.The CS component of cdma2000 1xRTT Revision A is not expected to be connected to the Evolve
30、d Packet Core.Bidirectional service continuity between cdma2000 HRPD(1xEV-DO)Revision A and E-UTRAN for best effort and real-time applicationsBidirectional service continuity between cdma2000 HRPD(1xEV-DO)Revision 0 and E-UTRAN for best effort applications,50,Service Continuity:3GPP&WiMAX Access,Bid
31、irectional service continuity between WiMAX(IEEE 802.16e)and GERAN PSBidirectional service continuity between WiMAX(IEEE 802.16e)and UTRAN PSBidirectional service continuity between WiMAX(IEEE 802.16e)and E-UTRANThrough the EPC,51,LTE Spectrum Re-farming&Migration,LTE 2.6GHz,UMTS 2.1G,2.1GHz,2.6GHz,
32、Re-farming,LTE 2.1GHz,UMTS 2.1GHz,If spectrum re-farming is permitted by regulators,part of 900/1800M,and part of 2.1G should be considered for using as LTE spectrum.Technology neutral is a trend in many countries,making re-farming more and more possible.Bandwidth of 1.4/3 MHz for LTE is more feasible in the near term than 5 MHz for HSPA+,e.g.in 900 MHz band.,GSM 900M/1.8G,900MHz/1.8GHz,Re-farming,LTE 900MHz/1.8GHz,GSM/EDGE 900MHz/1.8GHz,Thank you,Talking to the future,
