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Mobile communications: present and future(Part 2) By Dr. Abhaya Sumanasena MSc PhD CEng MIET MIEEEDelivered on 22 January 2009 @ SLINTEC
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Mobile communications:
present and future(Part- II)
Dr. Abhaya Sumanasena MSc PhD CEng MIET MIEEE
22 January 2009
Dr. Abhaya Sumanasena
Introduction to HSDPA
Dr. Abhaya Sumanasena
What is HSDPA ?
Dr. Abhaya Sumanasena
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)
Dr. Abhaya Sumanasena
Some Basics
Dr. Abhaya Sumanasena
Paths for packet and voice calls
Dr. Abhaya Sumanasena
HSDPA is only about data!
Downlink in R’99 & HSDPA
Dr. Abhaya Sumanasena
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
Dr. Abhaya Sumanasena
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
Dr. Abhaya Sumanasena
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
Dr. Abhaya Sumanasena
Coverage and Capacity
3.6 Mbps 1.8 Mbps 500 kbps
QAM3/4 coding QAM
1/2 codingQPSK
1/2 coding
Dr. Abhaya Sumanasena
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
Dr. Abhaya Sumanasena
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
Dr. Abhaya Sumanasena
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 ?
Dr. Abhaya Sumanasena
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
Dr. Abhaya Sumanasena
End User Experience
Impact of HSDPA’s High Data rates
Source: Qualcomm
Dr. Abhaya Sumanasena
HSDPA Success story
Dr. Abhaya Sumanasena
Source:GSMA
Current status
Notebook/PC modems 41.8%
Wirelessrouters
Phones/Consumer Devices 48.8%
Dr. Abhaya Sumanasena
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