LTE and WiMax Technology and Performance Comparison

Transcription

1 LTE and WiMax Technology and Performance Comparison Dr.-Ing. Carsten Ball Nokia Siemens Networks Radio Access, GERAN &OFDM Systems: RRM and Simulations EW2007 Panel Tuesday, 3rd April, Nokia Siemens Networks. All rights reserved.

2 Contents: Towards Broadband Wireless Access: Categorization of different Radio Access Standards Radio Access Solutions: the 3GPP and the IEEE Technology Family Detailed LTE vs. WiMax Comparison (Radio Perspective, Focus on lower Layers) Performance Numbers: Peak Data Rates, Spectrum Efficiency and Technology Capability Limits LTE or WiMax Market Success, what will be the winning Technology? Operator Use Cases and potential Ways of Acting Summary and Conclusions 2 Nokia Siemens Networks. All rights reserved.

3 Towards Broadband Wireless Access 3GPP and IEEE offer a comprehensive migration path to Beyond 3G Mobility / Range WiMAX (IEEE802.16d/e) covers fixed wireless and nomadic access, the e-standard extends towards (limited) mobility. HSPA Evolution and LTE target at high data rates combined with high subscriber mobility. GSM GPRS DECT EDGE BlueTooth UMTS (W-CDMA) GERAN Evolution (= EDGE-II) HSPA Systems HSPA Evolution WLAN (IEEE x) XDSL, CATV, Fiber beyond 3G IEEE e >2010 IEEE d LTE User data rate Mbps Both WiMax and LTE offer excellent User Data Rates in the order of Mbps (Bandwidth!). 3 Nokia Siemens Networks. All rights reserved. LTE design seems to be superior especially >>> Commercially concerning not Binding Mobility <<< and Data Throughput.

4 Radio Access Solutions at a Glance The 3GPP Technology Family GERAN (GSM/GPRS/EDGE) Large installed base with excellent large-area coverage Quick and cost-effective upgrade of existing networks Near-broadband data services with EDGE Phase II (up to 1 Mbps) Seamless 2G/3G handover worldwide coverage, global roaming UTRAN (W-CDMA/HSPA) HSPA to apply the full power of W- reduced network cost User experience comparable to DSL in terms throughput & latency High capacity, full mobility, high data security and QoS Quick and cost-effective upgrade of existing networks Seamless 2G/3G handover LTE 3G evolution towards full broadband multimedia services Significantly reduced network cost Flat Architecture, fully IP based Flexible bandwidth and spectrum usage Full mobility, security, QoS assets Seamless 2G/3G/LTE handover Full mobility with medium data rates High speed data rates with full mobility Broadband multimedia at lowest cost Clear 3GPP Evolution Path towards LTE, comprehensive 2G/3G/4G interworking, easy upgrade & 4 Nokia Siemens Networks. All rights reserved. re-farming potential, seamless services >>> Commercially (handover, not Binding <<< roaming), full high-speed mobility.

5 Radio Access Solutions at a Glance The IEEE Technology Family WLAN (IEEE ) Solution for specific markets including municipal networks and backhauling in combination with other radio access technologies, e.g. WiMAX backhaul for WLAN or WLAN backhaul for GSM Hotspot business solution to complement MNO s offering High capacity for stationary use WiMAX stationary (IEEE d) Fixed or mobile network operators Optimized wireless-dsl services (Voice + data) Support of charging/billing typical for DSL (e.g. user classes, volume/flat-rate packages) High capacity for stationary use Selective QoS WiMAX mobile (IEEE e) Fixed or mobile network operators Optimized wireless-dsl services (Voice + data) Support of charging/billing typical for DSL (e.g. user classes, volume/flat-rate packages) High capacity; Limited mobility Selective QoS Large capacity for metro networks High speed data rates for fixed wireless access High speed data rates with limited mobility Modular stand-alone Standards allowing for easy combinations and offering high >>> Commercially performance. not Binding <<< 5 Nokia Siemens Networks. All rights reserved.

6 LTE vs. WiMax Comparison (Radio Perspective) Network Architecture WiMax e Flat, IP based; BS + ASN GW LTE Very Flat, IP based enodeb + agw Comments Both technologies with significantly reduced number of nodes compared to 2G/3G. Services Packet Data, VoIP Packet Data, VoIP Mobility Access technology Channel BW FFT-Size and Subcarrier Spacing Cyclic Prefix Spectrum Duplex Mode Framing, TTI Modulation & Coding Mobile IP with targeted Mobility < 120 km/h Scalable OFDMA in UL & DL 1.25, 3.5, 5, 7, 8.75, 10, 14, 15, 20, 28 MHz ; df variable; 7-20 khz typically 10 khz Flexible 1 / 32,.,1 / 4; CP typical 1 / 8 Licensed & unlicensed, 2.3, 2.5, 3.5 & 5.8 GHz TDD + FDD TDD focus 2,, 20 ms; 5 ms focus BPSK,, 64-QAM; CC + CTC (+BTC+LDPC) Full 3GPP Mobility with Target up to 350 km/h; 2G/3G Handover and Global Roaming DL: OFDMA, UL: SC-FDMA 1.25, 2.5, 5, 10, 15, 20 MHz ; fixed df = 15 khz Short (5 µs) or Long CP (17 µs) Licensed, IMT-2000 Bands FDD + TDD FDD focus fixed 2*0.5 ms slots = 1 ms sub-frames QPSK,, 64-QAM; CC + CTC LTE is fully embedded in the 3GPP world incl. interrat HO. SC-FDMA reduces PAPR by ~5 db UL improvements!!! Both very flexible Large df required against Doppler => higher velocity Both designed to combat Multipath Fading in different Environments LTE available at preferred low Frequency Bands Coverage Advantage TDD requires Synchronization, FDD can be asynchronous. TTI determines the Latency / PING 6 Nokia Siemens Networks. All rights reserved.

7 LTE vs. WiMax Comparison (Radio Perspective) MIMO, # Antennas MIMO Modes HARQ Subchannel / Physical Resource Block Interleaving / Mapping Pilot Assisted Channel Estimation (PACE) Overall MAC Layer L1/L2 Signalling User Multiplexing WiMax BS: 1, 2, 4 ; MS: 1, 2 Closed + open Loop Diversity + Spatial Multi. Chase Comb. + IR; stop & wait 24 x 2 Constellation Points in PUSC Mode Adjacent AMC 2x3 or PUSC/FUSC Permutation; Focus Permutation DL Preamble + distributed permuted Pilots depending on # Antennas VoIP + Data Mixture typically ~ 25 % Flexible FCH + MAP following the Preamble; Sync. by Ranging CH Flexible arbitrary Rectangles in T-F-Domain LTE enodeb: 1, 2, 4 ; UE: 2 Closed + open Loop Diversity + Spatial Multi. Chase Comb. + IR; N=8 stop & wait; UL Sync., DL Async. 12 x 14 Constellation Points Localized + Distributed; Focus Localized Distributed Pilots depending on # Antennas VoIP + Data Mixture typically ~ % Signaling Channels in max. first 3 Symbols; Separate BCH, SCH Stripe-wise Allocation in F-Domain Comments LTE working assumption is 2 DL Antennas per UE LTE prefers frequency selective Packet Scheduling, WiMax focuses on interference averaging. LTE is more efficient, e.g. VoIP optimizations LTE provides optimized and more efficient L1/L2-Signaling also utilizing CDM components LTE with less complex Ressource Signaling 7 Nokia Siemens Networks. All rights reserved.

8 Performance Numbers Peak Data Rates Mbps Downlink Uplink Peak data rates > 150 Mbps 2 x 5 MHz 2 x 5 MHz 1 x 10 MHz 1 x 20 MHz 2 x 10 MHz 2 x 20 MHz HSPA Release 6 HSPA Release 8 WiMAX e WiMAX e LTE Release 8 LTE Release 8 Rather similar Peak Data Rates for HSPA evolution and WiMAX LTE provides outstanding Data Rates beyond 150 Mbps in 2 x 20 MHz Bandwidth due to less overhead WiMAX uses asymmetric 29:18 TDD in 10/20 MHz, whereas HSPA and LTE use FDD with 2 x 5 and 2 x 10/20 MHz Prerequisite: 2x2 MIMO with 64-QAM in Downlink 8 Nokia Siemens Networks. All rights reserved.

9 Performance Numbers Spectrum Efficiency Benchmarking Downlink Uplink Full Buffer Simulation Results bps/hz/cell HSPA R6 (TU channel) HSPA R6 (Vehicular A) HSPA R7 MIMO + 64QAM + equalizer WiMAX reuse 3 (29:18 TDD) LTE Similar spectral efficiency for HSPA evolution and WiMAX due to similar Feature Set LTE is expected to provide higher efficiency than HSPA or WiMAX WiMax assumed to be deployed in recommended frequency reuse 1/3, HSPA is definitely deployed in real reuse 1, whereas LTE utilizes fractional tight reuse due to coordinated interference reduction 9 Nokia Siemens Networks. All rights reserved.

10 Performance Numbers Mobile Technology Capability Limits 6"# $ "#$% &"#'( 2$3 4 > 0<!1! 1 1! )&*( 1, +, +,,?1, " --). / 0%0! 0! ?01 0 " --);.* / + +!1 11 4! "*, 9: 9: :!81! 6 <* &= *( 0 %0!, 0 %0!, 0 01, 0 %0!, +, All radio standards show comparable performance under comparable conditions and similar feature set: Laws of physics apply to all of them User rates mainly depend on bandwidth, modulation/coding and availability of MIMO (2x2 assumed) Spectrum Efficiency is determined by Frequency Reuse and Feature Set (e.g. FSPS, MIMO, ) Latency (e.g. PING Performance) depends on chosen Frame Duration or TTI Coverage depends on frequency band, RF power limitations and duplex mode 10 Nokia Siemens Networks. All rights reserved.

11 LTE or WiMax Market Success, what will be the winning Technology? Choosing the right technology path depends on each operator s individual situation Regulatory constraints E.g. Available spectrum Spectrum cost Standards compliance E.g. Population density Traffic distribution Demand for services Spending on communication Availability and variety of terminals Site Locations Regional constraints Data rates Technological constraints Capacity Latency Mobility Operator strategy Technical characteristics are just one part of the story!!! E.g. Service offering Competitive situation Legacy networks Investment Protection Future proofness Technology Evolution Path OPEX Terminal Costs 11 Nokia Siemens Networks. All rights reserved.

12 LTE or WiMax Market Success, what will be the winning Technology? Looking at typical operator use cases, there are most applicable and probable ways of acting Mobile Network Operator Incumbent 2G/3G mobile operator New 3G mobile operator Incumbent 2G mobile operator with BWA (non-3g) license Extend 3G to HSPA Extend 2G to EDGE and EDGE II Upgrade to LTE later Build up UMTS/HSPA network Upgrade to LTE later Extend to EDGE and EDGE II for mobile data In addition, use WiMAX mostly in urban-area hot-zones, with focus on fixed-line substitution (voice & data) since HSPA not possible. Access Provider, Fixed Networks New operator with BWA (non-3g) license No license available Use WiMAX for licensed bands, 3.5 GHz FDD (fixed/nomadic) or 2.5 GHz TDD (fixed/nomadic/mobile) Use WLAN for hotspot/metro networks 12 Nokia Siemens Networks. All rights reserved.

13 Summary and Conclusions: Spectrum Services Mobility Backwards Compatibility Roaming Performance Availability IMT2000 other Circuit Switched, Voice Packet Switched, Data Full Mobility Nomadic Mobility Coverage Capacity Latency LTE (VoIP) full 3GPP interoperability (LTE-900) 2009/2010 WiMAX Mobile WiMax IMT-2000 member (2.3, 2.5 & 3.5 GHz) (VoIP) ( ) WiMax to WiMax, if f < 3.5GHz ( ) ( ) 2007/2008 LTE comes ~ 2 years later than WiMax and hence provides some technical advantages over WiMax. LTE must be seen especially in the context of the mature and world-wide dominating GERAN and UMTS/HSPA Systems allowing for Handover/Roaming as well as Refarming Scenarios. Judgment on the best technology, however, depends on specific operator needs and prerequisites. LTE and WiMax are basically for different customers in different spectrum: no strong Competition. 13 Nokia Nokia Siemens Networks. All rights reserved. is pleased to offer a strong and comprehensive Portfolio including both WiMax and LTE operating even on the same Platform (NSN FlexiBTS).

14 Thank You 14 Nokia Siemens Networks. All rights reserved.

15 Dr.-Ing. Carsten Ball Dr. Carsten Ball received the Dipl.-Ing. degree in electrodynamics in 1993 and the Dr.-Ing. degree in electrical engineering in 1996 from the Technical University of Karlsruhe, Germany. Since 1997 he is with Siemens Mobile Networks and since April 2007 with Nokia Siemens Networks (NSN) in Munich, Germany, currently heading the GERAN and OFDM Systems Architecture Radio & Simulation group. He is responsible for the GSM, GPRS and EDGE performance as well as for the upcoming OFDM radio technologies (WiMax, LTE). Dr. Ball s research interests include simulation, protocol stacks, optimization and efficient algorithm design in cellular radio networks. 15 Nokia Siemens Networks. All rights reserved.

16 Backups: 16 Nokia Siemens Networks. All rights reserved.

17 Flat Architecture Evolution Flat architecture = single network element in radio network and in the core network Significant Node Reduction compared to previous GERAN and UMTS Standard Same architecture in i-hspa, LTE and in WiMAX! $% 9:"#! # " 17 Nokia Siemens Networks. All rights reserved.

18 Cell Range for Mobile and Fixed Wireless Good quality Fixed wireless WiMAX network can be built for outdoor antennas with GSM/EDGE and UMTS/HSPA sites Mobile WiMax suffers from Coverage Challenge (especially indoor) due to high Frequency Bands LTE provides comparable coverage to GSM/EDGE 900 MHz) or HSPA MHz) Suburban coverage WiMAX 3500 outdoor fixed WiMAX 2500 outdoor fixed WiMAX 3500 indoor mobile WiMAX 2500 indoor mobile HSPA2100 indoor mobile HSPA900 indoor mobile Uplink Downlink Fixed application No indoor loss CPE Antenna height 5 m Mobile application Indoor loss 15 db MS Antenna height 1.5 m Nokia Siemens Networks. All rights reserved. km

19 Key success factors show clear profiles for available technologies Economy of scale IPR regime Spectrum availability and cost impact Variety of terminals GSM GPRS EDGE Economy of scale IPR regime Spectrum availability and cost impact Variety of terminals UTRAN HSPA Compatibility with existing standards Voice performance Compatibility with existing standards Voice performance Lean architecture Broadband data performance Lean architecture Broadband data performance Full mobility with medium data rates High speed data rates with full mobility Economy of scale Spectrum availability and cost impact LTE Economy of scale Spectrum availability and cost impact WiMAX IPR regime Variety of terminals IPR regime Variety of terminals Compatibility with existing standards Voice performance Compatibility with existing standards Voice performance Lean architecture Broadband data performance Lean architecture Broadband data performance Broadband multimedia at lowest cost High speed data rates with limited mobility 19 Nokia Siemens Networks. All rights reserved.

20 Technology Choice is Defined by Current Network, Spectrum Assets and Voice )A > 6" ;A >&C9#( ; A > B B B " ; A B -,< A B > 6"#'2 LTE and WiMax are basically for different customers in different spectrum: no strong Competition expected 20 Nokia Siemens Networks. All rights reserved.