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Dimensioning, configuration and
deployment of Radio Access
Networks.
part 5: HSPA and LTE
HSDPA
Enhanced Support for Downlink Packet Data
Higher Capacity
Higher Peak data rates
Lower round trip delay time
Part of release 5
Similar to cdma2000 EV DO
Shared Channel Transmission
Higher order Modulation
Fast Link adaptation
Fast hybrid ARQ
(MIMO to be considered for later releases)
Shared Channel Transmission
Efficient code and power utilization by dynamically sharing radio resources among multiple users
Time domain (TTI = 2 ms)
Code domain (up to 15 codes)
Not all UEs are capable to receive data in consecutive TTI (Minimum inter-TTI time > 1)
CC are not orthogonal due to multipath propagation self interference generated in the cell affecting capacity
Channelization codes allocated
for HS-DSCH transmission
8 codes (example)SF=16
SF=8
SF=4
SF=2
SF=1
User #1 User #2 User #3 User #4
TTI
Sharedchannelization
codes
time
HSDPA - Shared channel transmission
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Channel coding and throughput
Channel coding at rates 1/4-3/4 Dynamically changed
Higher order Modulation
Allows for higher peak data rates QPSK 480kbps channel bit rate per code
16QAM 960kbps channel bit rate per code Requires higher SNIR
Smaller cells
Shared channel transmission
Radio channel conditions changes fast due to:
Interference variations
Path loss and shadowing
Multipath fading
HS-DSCH channel rate control = constant power
Adaptive channel coding Adaptive modulation (QPSK 16QAM)
Fast adaptation - TTI=2 ms
Available rate is adjusted by selecting a Transport Format and Resource Combination (TFRC)
The achievable rate dependent on:
Available HS power
Radio conditions
UE category
Available # HS codes 16QAM availability
Load
Fast link adaptation Modulation, coding and data rate
Modulat ion Coding rateThroughput5
CC
Throughput
10 CC
Throughput
15 CC
QPSK
1/4 600 kbps 1.2 Mbps 1.8 Mbps
2/4 1.2 Mbps 2.4 Mbps 3.6 Mbps
3/4 1.8 Mbps 3.6 Mbps 5.4 Mbps
16QAM
2/4 2.4 Mbps 4.8 Mbps 7.2 Mbps
3/4 3.6 Mbps 7.2 Mbps 10.8 Mbps
4/4 4.8 Mbps 9.6 Mbps 14.4 Mbps
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SINR vs throughput
Throughput is afunction of modulation,
coding and SNIR
RNC
Air interface limitations HW limitations
Channel elements
in NodeB
Transmission(x E1)
- DL power
- DL codes
- UL interference
Capacity management overview 3G RAN
384 kbps384 kbps384 kbps
1Mbps
0.5Mbps
Power control
Constant bit rate
RNC
R99
Power controlled
Power control and rate control
Rate control
Constant DL power
RNC
R5
Rate controlled5Mbps3Mbps
384 kbps
Deployment strategy example
f1: R99
Hot spots
Dense urban
Urban
Suburban
Rural
Deployment
phase
f2: R99 + HS
f1: R99 + HS
f2: R99 + HS
f1: R99 + HS
f1: R99 + HS
f2: R99 + HS
f1: R99
f1: R99 + HS
Initial phase
Mature phase
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LTE 4G Mobile Broadband
A SHORT SUMMARY ON BEHALF OF ERICSSON
HSPA and LTE = Mobile Broadband
HSPA High-Speed Packet Access (Turbo-3G)
Gradually improved performance in existing 3G networks
LTE Long-Term Evolution (4G) Significantly higher performance and user experience
in a wide range of spectrum allocations
Packet-switched services only
Fulfills IMT-Advanced requirements
Studies Specs
LTE LTE-Advanced
HSPA HSPA evolutionHSDPA
2004 2006 20082002
Requirements
WCDMA
2005 2007
Stefan Parkvall
LTE 4G Mobile Broadband
via trials
to commercial operation!
http://www.teliasonera.com/4g/index.htm
LTE Testbed
2007
http://www.ericsson.com/thecompany/press/releases/2009/12/1360881
Testbed 2007, 20 MHz, 2x2 MIMO
12
23
37
54
74
97
123
154
700 m
From early studies
Rel-9 Rel-10Rel-8
Basic LTE functionality Enhancements & extensions Further extensions
IMT-Advanced compliant
FDD and TDD supportBandwidth flexibility
ICICMulti-antenna supportdata1
data2
data3
data4
C ha nn el -d ep en de nt sch ed ul in g H yb ri d ARQ
OFDM t ransmission
MBMS Carrier Aggregation
Relaying
Multi-antenna extensionsDual-layer beamforming
Positioning
LTE Basic Radio-Access Principles
2008 2009 2010
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Transmission Scheme
Downlink OFDM Parallel transmission on large number of
narrowband subcarriers
Uplink DFTS-OFDM DFT-precoded OFDM
Benefits:
Avoid own-cell interference
Robust to time dispersion
Main drawback
Power-amplifier efficiency
Tx signal has single-carrier properties
Improved power-amplifier efficiency
Improved battery life
Reduced PA cost
Critical for uplink
Equalizer needed Rx Complexity
Not critical for uplink
Cyclic-prefix
insertion
OFDM modulatorDFT precoder
DFT IFFTIFFTCyclic-prefix
insertion
Multi-antenna Transmission
Diversity for improvedsystem peformance (robustness)
Beam-forming for improved coverage(less cells to cover a given area)
SDMA for improved capacity(more users per cell)
Multi-layer transmisson (MIMO)for higher data rates in a given bandwidth
The multi-antenna technique to use depends on what to achieve
Spectrum Flexibility
Operation in differently-sized spectrum allocations
Core specifications support any bandwidth from 1.4 to 20 MHz
Radio requirements defined for a limited set of spectrum allocations
6 RB (1.4 MHz)
100 RB (20 MHz)
Support for paired andunpaired spectrum allocations
time
FDDtime
Half-duplex FDD(terminal-side only)
timeTDD
10 MHz 15 MHz 20 MHz3 MHz 5 MHz1.4 MHz
with a single radio-access technology economy-of-scale
Supported Frequency Bands
20251710
19801785 18801805
2110 2200
2110 2170
26902500
2500 2570 2620 26901710
2300 2400
General
bands
Regional
bands
Local
bands
Band 3 Band 1 Band 7
Band 2
Band 4
Band 10
Paired Uplink Paired Downlink
Legend:
Unpaired
19101850 19901930
15251427
IMT IMT IMTITU: IMTMobile
B an d 11 & 21 (J ap an ) B an d 9 (J ap an )
Band 39 (China)
Band 36Band 35
(Band 37)
19101850 19901930
Band 33Band 34
Band 40
Band 38
Band 41
2496 2690
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Supported Frequency Bands
Paired Uplink Paired Downlink
Legend:
960698
IMT
General
bands
Local bands
824 849 869 894
830 845 885875
880 915 925 960
Band 8
Band 5Band 12Band 13
Band 14
Band 18 &19 (Japan)
ITU:
Band 17
815 860
791 821 832 862
Band 20
Regional
bands
Rel-9 Rel-10Rel-8
Basic LTE functionality Enhancements & extensions Further extensions
IMT-Advanced compliant
FDD and TDD supportBandwidth flexibility
ICICMulti-antenna supportdata1
data2
data3
data4
C ha nn el -d ep en de nt sch ed ul in g H yb ri d ARQ
OFDM t ransmission
MBMS Carrier Aggregation
Relaying
Multi-antenna extensionsDual-layer beamforming
Positioning
LTE Continuous Evolution
2008 2009 2010
RelayingRel-10
Repeater
Possible already in Rel-8, simply amplifies and retransmits recevied signal
Relaying (added in Rel-10)
Relay = small base station connected to RAN using LTE radio resources
Mainly interesting if fibre/microwave backhaul is more expensive than using LTE
spectrum
Relay cell
Donor cell
HetNets
What?
Low power nodes placed throughout a macro-cell layout
Heterogeneous Networks
Conventional
Independent pico cells
Relay
Independent relay cells
Relay connected to macro
RRU
Remote pico antenna,
processing in macro
No new pico cells
Why?High data rates dense infrastructure...but non-uniform user
distribution
Macro for coverage, pico for high data ratesHow?
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The Wireless Evolution
Additional functionality and
capabilities
Improved performance
New application areas
Everything is connected 50 billion devices
Need for new business models?
More Reading
Available in English, Chinese, Korean and Japanese.
...or read The Book!
Open the 3GPP specifications...