Transcript
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, 2007
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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
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Towards Broadband Wireless Access 3GPP and IEEE offer a comprehensive migration path to Beyond 3G WiMAX (IEEE802.16d/e) covers fixed wireless and nomadic access, the e-Standard extends towards (limited) mobility.
Mobility / Range
HSPA Evolution and LTE target at high data rates combined with high subscriber mobility.
Systems
UMTS (W-CDMA)
beyond 3G HSPA
GSM GPRS
>2010
HSPA Evolution
EDGE GERAN Evolution
IEEE 802.16e
LTE
(= EDGE-II)
WLAN
DECT
(IEEE 802.11x)
BlueTooth 0.1
XDSL, CATV, 1
Fiber 10
IEEE 802.16d
User data rate 100
Both WiMax and LTE offer excellent User Data Rates in the order of 10 – 160 Mbps (Bandwidth !). 3
© Nokia Siemens Networks. All rights reserved. >>> Commercially not Binding <<< and Data Throughput. LTE design seems to be superior especially concerning Mobility
1000
Mbps
Radio Access Solutions at a Glance
The 3GPP Technology Family GERAN (GSM/GPRS/EDGE)
UTRAN (W-CDMA/HSPA)
• Large installed base with excellent
• HSPA to apply the full power of W-
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
Full mobility with medium data rates 4
CDMA @ 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
High speed data rates with full mobility
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
Broadband multimedia at lowest cost
Clear 3GPP Evolution Path towards LTE, comprehensive 2G/3G/4G interworking, easy upgrade & © Nokia Siemens Networks. All rights reserved. >>> Commercially not Binding <<< roaming), full high-speed mobility. re-farming potential, seamless services (handover,
Radio Access Solutions at a Glance
The IEEE Technology Family WLAN (IEEE 802.11) • 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
Large capacity for metro networks 5
WiMAX stationary (IEEE 802.16d)
WiMAX mobile (IEEE 802.16e)
• Fixed or mobile network operators • Optimized wireless-DSL services
• 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
High speed data rates for fixed wireless access
(Voice + data)
• Support of charging/billing typical for DSL (e.g. user classes, volume/flat-rate packages)
• High capacity; Limited mobility • Selective QoS
High speed data rates with limited mobility
Modular stand-alone Standards allowing for easy combinations and >>> Commercially not Binding <<< offering high performance.
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LTE vs. WiMax Comparison (Radio Perspective) WiMax 802.16e
LTE
Comments
Flat, IP based; BS + ASN GW
Very Flat, IP based eNodeB + aGW
Both technologies with significantly reduced number of nodes compared to 2G/3G.
Packet Data, VoIP
Packet Data, VoIP
Network Architecture Services Mobility Access technology Channel BW FFT-Size and Subcarrier Spacing Cyclic Prefix Spectrum Duplex Mode Framing, TTI Modulation & Coding 6
Full 3GPP Mobility with LTE is fully embedded in the Target up to 350 km/h; 2G/3G Handover and 3GPP world incl. interRAT HO. Global Roaming DL: OFDMA, Scalable OFDMA SC-FDMA reduces PAPR by in UL & DL ~5 dB UL improvements !!! UL: SC-FDMA 1.25, 3.5, 5, 7, 8.75, 10, 1.25, 2.5, 5, 10, Both very flexible 14, 15, 20, 28 MHz 15, 20 MHz 128- 2048; Large dF required against 128 – 2048; dF variable; Doppler => higher velocity 7- 20 kHz typically 10 kHz fixed dF = 15 kHz Both designed to combat Flexible 1 / 32, ….,1 / 4; Short (5 µs) or Long CP Multipath Fading in different CP typical 1 / 8 (17 µs) Environments Mobile IP with targeted Mobility < 120 km/h
Licensed & unlicensed, 2.3, 2.5, 3.5 & 5.8 GHz
Licensed, IMT-2000 Bands
LTE available at preferred low Frequency Bands Coverage Advantage
TDD + FDD TDD focus 2, …, 20 ms; 5 ms focus BPSK, …, 64-QAM; CC + CTC (+BTC+LDPC)
FDD + TDD FDD focus fixed 2*0.5 ms slots = 1 ms sub-frames QPSK, …, 64-QAM; CC + CTC
TDD requires Synchronization, FDD can be asynchronous.
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TTI determines the Latency / PING
LTE vs. WiMax Comparison (Radio Perspective) MIMO, # Antennas MIMO Modes
LTE
Comments
BS: 1, 2, 4 ; MS: 1, 2 Closed + open Loop
eNodeB: 1, 2, 4 ; UE: 2 Closed + open Loop
LTE working assumption is 2 DL Antennas per UE
Diversity + Spatial Multi. Diversity + Spatial Multi.
stop & wait
Chase Comb. + IR; N=8 stop & wait; UL Sync., DL Async.
24 x 2 Constellation Points in PUSC Mode
12 x 14 Constellation Points
Chase Comb. + IR;
HARQ Subchannel / Physical Resource Block
WiMax
LTE prefers frequency selective Adjacent AMC 2x3 or Localized + Distributed; Packet Scheduling, Interleaving / Mapping PUSC/FUSC Permutation; Focus Localized WiMax focuses on interference Focus Permutation averaging. DL Preamble + distributed
Distributed Pilots depending on # Antennas
VoIP + Data Mixture typically ~ 25 %
VoIP + Data Mixture typically ~ 15-20 %
LTE is more efficient, e.g. VoIP optimizations
Flexible FCH + MAP following the Preamble; Sync. by Ranging CH
Signaling Channels in max. first 3 Symbols; Separate BCH, SCH
LTE provides optimized and more efficient L1/L2-Signaling also utilizing CDM components
Pilot Assisted Channel permuted Pilots Estimation (PACE) depending on # Antennas Overall Overhead @ MAC Layer L1/L2 Signalling User Multiplexing 7
Flexible arbitrary Stripe-wise Allocation in F-Domain Rectangles in T-F-Domain
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LTE with less complex Ressource Signaling
Performance Numbers
Peak Data Rates
Peak data rates
> 150 Mbps
100 90 80
Downlink Uplink
70 60 Mbps 50 40 30 20 10 0 2 x 5 MHz
2 x 5 MHz
HSPA Release 6
HSPA Release 8
1 x 10 MHz 1 x 20 MHz 2 x 10 MHz 2 x 20 MHz WiMAX 802.16e
WiMAX 802.16e
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
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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: MIMO with 64-QAM in Downlink Nokia Siemens Networks. All2x2 rights reserved. >>> Commercially not Binding <<<
Performance Numbers
Spectrum Efficiency Benchmarking 2.5
bps/Hz/cell
2.0
Downlink Uplink
Full Buffer Simulation Results
1.5 1.0 0.5 0.0 HSPA R6 HSPA R6 (TU channel) (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, 9
HSPA is definitely deployed in real reuse 1, whereas LTE utilizes fractional tight © Nokia Siemens All rights reserved. reuse dueNetworks. to coordinated interference reduction >>> Commercially not Binding <<<
Performance Numbers
Mobile Technology Capability Limits 6
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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
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,
LTE or WiMax Market Success, what will be the winning Technology ?
Choosing the right technology path depends on each operator’s individual situation E.g. Regulatory constraints
Available spectrum Spectrum cost Standards compliance
Da ta
E.g. Population density Traffic distribution Demand for services Spending on communication Availability and variety of terminals Site Locations
y nc te La
ra te s
E.g.
Technological constraints Regional constraints
Ca pa ci ty
y lit i b Mo
Operator strategy
Technical characteristics are just one part of the story !!! 11
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Service offering Competitive situation Legacy networks Investment Protection Future proofness Technology Evolution Path OPEX Terminal Costs
LTE or WiMax Market Success, what will be the winning Technology ?
Access Provider, Fixed Networks
Mobile Network Operator
Looking at typical operator use cases, there are most applicable and probable ways of acting
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• Extend 3G to HSPA • Extend 2G to EDGE and EDGE II • Upgrade to LTE later
Incumbent 2G/3G mobile operator
• Build up UMTS/HSPA network • Upgrade to LTE later
New 3G mobile operator
Incumbent 2G mobile operator with BWA (non-3G) license
New operator with BWA (non-3G) license No license available
• 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.
• 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
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Summary and Conclusions: LTE Spectrum Services Mobility
IMT2000 other Circuit Switched, Voice Packet Switched, Data Full Mobility Nomadic Mobility
Backwards Compatibility
Coverage Capacity Latency
Availability
ᅛ ᅛ ᅛ (VoIP) ᅛᅛᅛ
WiMax IMT-2000 member ᅛ (2.3, 2.5 & 3.5 GHz) ᅛ ᅛ (VoIP) ᅛᅛᅛ
ᅛᅛ ᅛᅛ
ᅛ ᅛᅛ
ᅛᅛ full 3GPP interoperability
ᅝ
ᅛᅛ
Roaming
Performance
ᅛ ᅝ
WiMAX Mobile
(ᅛ) WiMax to WiMax
ᅛᅛ ᅛ ᅛ ᅛ (LTE-900)
ᅛ ᅛ ᅛ, if f < 3.5GHz
ᅛᅛᅛ
ᅛ ᅛ (ᅛ)
2009/2010
2007/2008
ᅛᅛᅛ
ᅛ ᅛ(ᅛ)
• 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.
Siemens Networks. All rights reserved. •13Nokia© Nokia Siemens Networks is pleased to offer a strong and comprehensive Portfolio including >>> Commercially not Binding <<< both WiMax and LTE operating even on the same Platform (NSN FlexiBTS).
Thank You …
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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.
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Backups:
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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
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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 (@900/2100 MHz)
Suburban coverage WiMAX 3500 outdoor fixed
Uplink Downlink
WiMAX 2500 outdoor fixed WiMAX 3500 indoor mobile
Fixed application No indoor loss CPE Antenna height 5 m
WiMAX 2500 indoor mobile
Mobile application Indoor loss 15 dB MS Antenna height 1.5 m
HSPA2100 indoor mobile HSPA900 indoor mobile 0.0
1.0
2.0
3.0 km
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4.0
5.0
Key success factors show clear profiles for available technologies Economy of scale
Spectrum availability and cost impact
IPR regime
Variety of terminals
Compatibility with existing standards
Lean architecture
GSM GPRS EDGE
Economy of scale
IPR regime
Compatibility with existing standards
Voice performance
Lean architecture
Broadband data performance
Full mobility with medium data rates Economy of scale
Spectrum availability and cost impact
IPR regime
Variety of terminals
Compatibility with existing standards
Lean architecture
Voice performance
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UTRAN HSPA
Variety of terminals
Voice performance
Broadband data performance
High speed data rates with full mobility LTE
Economy of scale
IPR regime
Compatibility with existing standards
Lean architecture
Broadband data performance
Broadband multimedia at lowest cost
Spectrum availability and cost impact
Spectrum availability and cost impact
WiMAX
Variety of terminals
Voice performance
Broadband data performance
High speed data rates with limited mobility
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Technology Choice is Defined by Current Network, Spectrum Assets and Voice Strategy @"
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LTE and WiMax are basically for different customers in different spectrum: no strong Competition expected 20
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