Mobile communications:

present and future(Part- II)

Dr. Abhaya Sumanasena MSc PhD CEng MIET MIEEE

22 January 2009

Dr. Abhaya Sumanasena

Introduction to HSDPA

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What is HSDPA ?

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Overview 3GPP WCDMA Evolution

UL= UplinkDL=Downlink

DL: 100 mbpsUL: 50 mbps

LTE

Dr. Abhaya Sumanasena

HSDPA

• HSDPA services provide users with a "broadband experience" today on mobile• HSDPA delivers a 5-fold increase in downlink data speeds.• It increases spectrum efficiency by using adaptive modulation and coding• HSDPA is a most cost effective way to provide high-speed broadband access

to both rural communities and the developing world [GSMA]• HSDPA users can roam up to 55 countries [GSMA]• Deployed in many frequency bands (850, 900,1700, 1800, 1900 and 2100 MHz)

Leverages the existing 3G assets• Spectrum• Subscriber base• Network infrastructure (sites, radio, core network, transmission)• Operation and Management system and staff• Subscriber management systems (authentication, billing)

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Some Basics

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Paths for packet and voice calls

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HSDPA is only about data!

Downlink in R’99 & HSDPA

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R’99 & HSDPA channel usage

R’99 uses dedicates the channels to user HSDPA shares

the channel

Node B

Dr. Abhaya Sumanasena

Dr. Abhaya Sumanasena

≈ SR

signal strength

Variable channel conditions

signal quality

Real time measurement for a stationary mobile

Current solution = power control

HSDPA solution: Adaptive Modulation and Coding

data rate is adjusted by modifying:• modulation scheme• effective code rate• number of codes

Modulation: 16QAMCoding: ½ rate

Modulation : QPSK Coding : 1/3 rate

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1 0

Modulation

0 1 0 1 1 0

1 1

0 1

0

1

QPSKmodulator

QAMmodulator

1 1

0 11 1

0 1

1 0

1 0

QAM symbolsQPSK symbols

bit stream from data service

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Coding

0 1 0 1

bit stream(4 bits)

½ rate Encoder 0 1 0 1 0 1 0 1

Encoded bits(8 bits)

Require higher bandwidth

0 1 0 1

bit stream(4 bits)

1/3 rate Encoder 0 1 0 1 0 1 0 1

Encoded bits(12 bits)

Require higher bandwidth

0 1 0 1

amount of redundancy increases

Coding gain increasesBandwidth increases

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Coverage and Capacity

3.6 Mbps 1.8 Mbps 500 kbps

QAM3/4 coding QAM

1/2 codingQPSK

1/2 coding

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Short frame adapts faster & reduces delay

10 ms

2 ms

2 ms

Short TTI (2 ms) in HSDPA

Reduced round trip delay

10 ms

Longer frame in R’99

Dr. Abhaya Sumanasena

Node B

Adaptation based on the Channel Quality Reporting

HSDPAModulation/coding According to proposed CQI

CQI information (every 2ms…..160ms)

UE

No of codes

1.44 mbps

1.44 mbps

1.6 mbps

1.6/2.8 mbps

1.6/2.24 mbps

1.6/2.56 mbps

1.6/2.88 mbps

1.6/3.2 mbps

1.6/3.36 mbps

1.6/3.36 mbps

1.6/3.36 mbps

Throughput

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Node B

UE Capabilities

1.2Mbps class

7 Mbps class

3.6 Mbps class

10 Mbps class

Released/soon to be released HSDPA handsets. CAT 12 (2Mbps) : LGE U830CAT 6 (3.6Mbps): Moto V3xx; LGE U970; Nokia N95; Nokia 6120; Classic, HUAWEI E220;USB Modem,SEM W910

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What do the operators have to do ?

Dr. Abhaya Sumanasena

Dr. Abhaya Sumanasena

RNC

More intelligence in the Node B

• Reduces the delay• Makes the system more efficient• New functions (Scheduling, Feedback handling, Adaptive modulation and coding)

Additional capacity Software upgrade

Core network

Base station(NodeB)UE

SWupgrade

Backhaulcapacity

Capacityupgrade

What is there for the user ?

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How fast ?

• Overhead (who the end user, where it is coming from, signalling) reduces the BW for actual information

• UE capability• Simultaneous connections• Network capability (not every Node B is ready)• Environment/interference• Backhaul Capacity • Speed of the content delivery

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End User Experience

Impact of HSDPA’s High Data rates

Source: Qualcomm

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HSDPA Success story

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Source:GSMA

Current status

Notebook/PC modems 41.8%

Wirelessrouters

Phones/Consumer Devices 48.8%

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July 2008, nearly one quarter (23 per cent) of people who access the internet away from home or work said that they did so using a USB dongle or datacard

HSPA devices•150 % annual growth on HSPA devices •637 devices by 3rd April 07•190 supports 3.6 Mbps•211 in 850 band•128 devices support 7.2 Mbps•91 devices in 1900 band•145 devices supports tri band 850/1900/2100•100 devices have WLAN•70% have EDGE

Whole range of products•48.8 % in phones/consumer devices•41.8 % in notebooks/pc modems•9.4 % in routers

Future Directions

Dr. Abhaya Sumanasena

LTEWhat is LTE: • The next step in the evolution of 3GPP (Rel-8) radio interfaces to deliver “global mobile

broadband”. • LTE is

– more about what user likes to have, about convenience and user experience – much about broadband and not about voice. Voice is not the driving force for LTE

Main services provided by LTE: messaging, internet surfing, VoIP

Performance Targets• Significantly improved spectrum efficiency and cell edge bitrate whilst maintaining same site locations

– DL target 3-4 times and UL target 2-3 times greater than HSDPA Release 6• Reduced CAPEX and OPEX (simple architecture, maximum reuse) resulting in low cost per bit• Soft handover no longer required and circuit-switched connectivity no longer supported• MIMO raises the number of users/cell by a factor of 10 compared to UMTS

Current status of development• The specifications were approved in September and December 2007. The work on the Layer 1 was closed in March 2008 and

open work on core specifications is planned to be finished in 2008. • NTT DoCoMo and Varizone announced LTE deployments in 2100 MHz and 700 MHz bands by 2010

Capabilities

800 MHz (?)

2600 MHz (70 MHz)

2100 MHz (60 MHz)

1800 MHz (75 MHz)

900 MHz (35 MHz)

20 Mhz 15 Mhz 10 Mhz 5 Mhz <5 Mhz

800 MHz (40 MHz)

2600 MHz (70 MHz)

2100 MHz (60 MHz)

1800 MHz (75 MHz)

900 MHz (35 MHz)

20 Mhz 15 Mhz 10 Mhz 5 Mhz <5 Mhz

Likely early deployment Likely later deployment

800 MHz (?)

2600 MHz (70 MHz)

2100 MHz (60 MHz)

1800 MHz (75 MHz)

900 MHz (35 MHz)

20 Mhz 15 Mhz 10 Mhz 5 Mhz <5 Mhz

800 MHz (48 MHz)

2600 MHz (70 MHz)

2100 MHz (60 MHz)

1800 MHz (75 MHz)

900 MHz (35 MHz)

20 Mhz 15 Mhz 10 Mhz 5 Mhz <5 Mhz

Likely early deployment Likely later deployment

800 MHz (?)

2600 MHz (70 MHz)

2100 MHz (60 MHz)

1800 MHz (75 MHz)

900 MHz (35 MHz)

20 Mhz 15 Mhz 10 Mhz 5 Mhz <5 Mhz

800 MHz (40 MHz)

2600 MHz (70 MHz)

2100 MHz (60 MHz)

1800 MHz (75 MHz)

900 MHz (35 MHz)

20 Mhz 15 Mhz 10 Mhz 5 Mhz <5 Mhz

Likely early deployment Likely later deployment

800 MHz (?)

2600 MHz (70 MHz)

2100 MHz (60 MHz)

1800 MHz (75 MHz)

900 MHz (35 MHz)

20 Mhz 15 Mhz 10 Mhz 5 Mhz <5 Mhz

800 MHz (48 MHz)

2600 MHz (70 MHz)

2100 MHz (60 MHz)

1800 MHz (75 MHz)

900 MHz (35 MHz)

20 Mhz 15 Mhz 10 Mhz 5 Mhz <5 Mhz

Likely early deployment Likely later deployment

Likely LTE deployment scenarios Data rates2x20 MHz

UL: 50 Mbps (peak)/ 20 Mbps (av)DL: 160 Mbps (peak)

Latency 10 ms

Spectral efficiency

Data: DL/UL 2.14/0.9 bps/Hz/cell Voice: DL/UL 45-55 users/MHz/cell

Spectrum IMT-2000 bands

Bandwidth 1.4, 3, 5,10,15, 20 MHz

User Experience

2-5 Mbps, better cell edge performance at lower cost

[source: 3gpp]

Regulatory aspects

Dr. Abhaya Sumanasena

• Principal duty under the Communications Act to further the interests of consumers, where appropriate by promoting competition

• Principal spectrum related duty to secure optimal use of the spectrum and competition between providers

• Three ways to manage the spectrum:1. Command & control. An approach whereby the regulator determines what the

spectrum can be used for and who should own it. Changes can only be made with the approval of the regulator. In 2004, this approach was used for over 90% of the spectrum.

2. Market forces. Under this approach flexible licenses are provided which allow the licence holder to change the use they put the spectrum to and to sell their licences to others (“liberalisation” and “trading”, respectively).

3. Licence exempt. Often termed unlicensed or “spectrum commons”, this approach allows anyone to use the spectrum without a licence as long as their equipment conforms to certain restrictions, normally relatively low transmit power levels. In 2004 around 6% of the spectrum was licence exempt, including the highly successful 2.4GHz band used for WiFi and BlueTooth.

Regulatory aspects

Thank you!

(please send your feedbackabhaya@theiet.org)

Dr. Abhaya Sumanasena