4. 4
1.1 Standardisation
•In 1997 there were many competing proposals for 3G.
• Europe (ETSI):
WCDMA, WTDMA,TDMA/CDMA, OFDMA, ODMA.
• North America(T1P1, TR45.3, TR45.5, TR46.1):
WCDMA N/A, UWC-136, cdma2000, WIMS WCDMA, WP-CDMA.
• Asia Pacific (ARIB & TTA):
WCDMA, WTDMA, OFDMA, Global CDMA 1 & 2.
•Dec 1998 saw a stand-off in standards.
• “Ericsson … is prepared to grant licences to these [W-CDMA & TD-CDMA] patents on
fair, reasonable and non-discriminatory basis in accordance with the ... ETSI IPR Policy.”
• “Qualcomm … is not prepared to grant licences according to the … ETSI IPR Policy.”
•Jun 1999 found compromise at the OHG.
• “Qualcomm and Ericsson ... jointly support approval by the International
Telecommunications Union (ITU) of a single CDMA third generation standard that
encompasses three optional modes of operation.”
5. 5
1.2 Harmonisation
•Now the ITU has recommended IMT-2000 for 3G mobile comms systems:
• 2 groups, 5 variants.
•CDMA effort has been harmonised into 2 groups:
• 3GPP for FDD & TDD
formed from ETSI, T1P1, TTC, CWTS, ARIB & TTA.
• 3GPP2 for MC
formed from TTA & TR45.5.
Single Carrier Multi-Carrier MC FDD TDD
UWC-136 DECT cdma2000 UTRA FDD UTRA TDD
TD-SCDMA
CDMATDMA
IMT-2000
6. 6
2.1 Scrambling
•What are scrambling codes?
• ‘W’ of WCDMA.
• Pseudo-random sequences: Gold codes, Kasami codes (M-sequences).
•How do they work?
• Converts a high amplitude, narrow bandwidth signal
in to a low amplitude, wide bandwidth signal.
•What are their important properties?
• High auto-correlation (at any time offset).
• Low cross-correlation (at any time offset).
•What does scrambling achieve?
• Spectral re-use factor of 1: all cells can use the same frequency spectrum.
• Benefits of wideband signals: multipath provides temporal diversity instead of ISI.
•What doesn’t scrambling achieve?
• Secure link: a linear sequence of length 2n-1 requires only n observations to crack it.
f
A A
f
7. 7
2.2 Spreading
•What are spreading/channelization/OVSF codes?
• ‘CDMA’ of WCDMA.
• Orthogonal sequences: Walsh-Hadamard codes).
•How do they work?
• ‘Cocktail party effect’: a guest will be
able to pick out conversations in his own language;
all other conversations sound like background noise.
•What are their important properties?
• High auto-correlation (when time-aligned).
• Low cross-correlation (when time-aligned).
•What does spreading achieve?
• Multiple services on a single link: spreading code identifies each service.
• Variable-rate services: spreading factor matches service rate to chip rate.
•What doesn’t spreading achieve?
• Infinite bandwidth: total bandwidth used by the services is still subject to Shannon’s Law!
Bonj our
Good
morning
Gut e n t ag
Buongiorno
9. 9
2.4 Uplink
• Uplink (not time-aligned)
• 1 scrambling code (Cs#) per UE.
• 1 or more channelization codes per UE.
Cs1
Cs2
Cs3
10. 10
2.5 Power Control
•Why is power control needed?
• Interference: each UE acts as an interferer to every other UE.
• Near-far effect: if UEs were to broadcast at a fixed level then those close to a Node-B
would have better SNR than those further away.
•What does power control do?
• UEs which are close to a Node-B ‘whisper.’
• UEs which are far from a Node-B ‘shout.’
•How is fast power control achieved?
• TPC bits inserted every slot (i.e. 1500 Hz).
• Outer loop copes with path loss and shadowing.
• Inner loop copes with fading.
11. 11
2.6 Soft Handover
•Soft handover
• Improves signal quality and reduces the chance of a dropped call.
• UE talks to cell #1 ...
• UE talks to cell #1 only.
… and starts to talk to cell #2.
• UE talks to cell #2 only.
13. 13
3.1 Network ‘Must Haves’
•Networks must satisfy users’ requirements on the 5 Cs.
• Capacity: high data rates on demand.
• Convergence: common access of seamless applications.
• Content: infotainment.
• Coverage: anywhere and everywhere.
• Cost: common infrastructure and platforms to reduce call overheads.
•These requirements tend to be inter-linked. For example:
• Common infrastructures ease coverage restrictions and reduce costs.
• Common platforms reduce costs and support convergence.
• Common services make convergence easier and content more widely available.
14. 14
3.2 Migration of Technology
•The anticipated migration path from 2G to 3G technology will be:
• 2G GSM CS slow data at 14.4 kbps;
• 2.5G GPRS PS data at 115 kbps. (it will support IP );
• 2.5G EDGE PS fast data at 384 kbps (it will enhance the radio element of the network);
• 3G WCDMA - very fast data at 2Mbps (it will use new licensed spectrum).
•Three network migration strategies are envisaged.
• Move to 3G via 2.5G using the current 2G network infrastructure and frequencies.
• Adopt 3G in dense urban areas, but keep 2.5G in sparse rural areas.
• Embrace 3G directly.
•Handsets are likely to be multi-mode.
• Support various generations of technology to cope with migration: e.g. 2G, 2.5G & 3G.
• Support several variants of 3G to allow global roaming: e.g. FDD & cdma2000 for
Europe and North America.
15. 15
3.3 Emergence of Mobile Internet
•3G will merge the Internet and wireless communications.
• Achieve fixed-mobile convergence.
• Networks are evolving from CS (circuit switched) to PS (packet switched).
• Control networks will change from SS7 (signalling system 7) to IP-based mechanisms.
•What is Mobile IP (Internet protocol)?
• IETF (Internet Engineering Task Force) proposed standard protocol RFC 2002.
• Provide access to the Internet or a home network no matter where a user is in the world.
•Why is Mobile IP important for 3G?
• IP is connectionless so access is much faster.
• IP is packet based so users are always ‘on-line’ but only pay to transfer data.
• IP offers a seamless service with end-to-end connectivity.
• IP allows less complex networks with fewer nodes (since fixed and mobile networks can
share infrastructure) which are much cheaper to operate.
• IP offers better traffic efficiency (due to effective network and services management).
• IP has a low packet overhead so is attractive for radio-access applications.
16. 16
3.4 Convergence of Services
•3G will blur traditional boundaries.
• Converge computing, communications and consumer devices.
• Platform-independent software (e.g. Java) running on a common service platform will
enable third-part applications to meet users’ end-to-end needs.
•What will service convergence offer?
• Perhaps a single ‘killer application.’
• Certainly a plethora of choice: mobile Internet, multi-media messaging and network-
based applications (so need to synchronise various databases on terminals).
•Why is service convergence important for 3G?
• Users will want to learn how to use an application once, not several times to cope with
different service creation/management tools on various networks.
• Providers will want to use off-the-shelf applications to create a new service once and
deploy it across a unified network, not custom-craft each service for each network.
• Subject to international roaming agreements 3G will allow network access from
anywhere on the globe and always using the same terminal.
17. 17
3.5 Strategy of Roll-out
•Roll-out strategies will vary around the globe.
• Existing Japanese PHS network is under severe strain and the Japanese government
will only license new spectrum for use by a more efficient technology (e.g. WCDMA).
• Existing UK GSM network is under strain on one band in some metropolitan areas but
additional cells can still be added.
•United Kingdom
• In service 2002-3.
• Islands of 3G in a sea of GSM to begin.
• 80% population coverage by 2007.
•Japan
• In service 2001.
• Countrywide coverage from start.
• 100% population coverage by 2002.
18. 18
4.1 Terminal ‘Must Haves’
•Terminals must satisfy users’ needs for the 5 Ps.
• Portal: user-friendly interface.
• Power-period: adequate standby and in-use time.
• Portable: small and lightweight.
• Protection: private and secure.
• Price: affordable.
•These requirements tend to be inter-linked. For example
• Diversity of terminals will give people a choice of portal features at a range of prices.
• Compact terminals will be more portable but have a reduced power-period.
• Feature-rich terminals will provide a great portal interface but their complexity may make
them harder to protect against soft-attack.
19. 19
4.2 Evolution of Terminals
•The expected evolution of terminals will be
• 2 Smart phone:
Support video streaming and web access, have an in-
built camera and larger display for video.
• 1 Basic phone:
Support voice and store all its information on the network.
• 4 Integrated into:
Cars, fridges etc.
• 3 Personal digital assistant:
An information centre with on-
device storage and wireless
detachable keypad.
terminals shown are
All concept
designs proposed by Ericsson.
20. 20
4.3 Securing Data
•Secure communications will be vital to the success of 3G.
• Users will want to access information from a VPN (virtual private network) and to conduct
e-commerce transactions anywhere in the world.
• Interoperable software and the complexity demanded of a feature-rich terminal may
leave them vulnerable to viruses and hacking.
• Adnan Al-Adnani (Panasonic): “It is a major concern for operators and they won’t
introduce anything until it’s secure.”
•3G networks will incorporate 2 major security measures.
• Cryptography: 128 bit keys (near-impossible for even computers to break).
• Authentication: establish the identity of both user and base station as users
pass between different networks.
•3G terminals will have security designed-in, not added-on.
• OS will probably use Java which has in-built security features to give protection against
rogue programs trying to access restricted parts of the OS or other applications.
• External high level scripts will be allowed little or no access to the underlying hardware.
21. 21
4.4 Safeguarding Devices
•Secure terminals will also be a must if 3G is to succeed.
• A 3G terminal will be a wallet for electronic cash, a fob for electronic keys, and a
strongbox for private email.
• It must be rendered useless as soon as it’s lost.
• Eric Chien (Symantec): “They [3G devices] will definitely be targeted. The question is to
what extent.”
•3G terminals will initially include a USIM (User Services Identity Module) to
deter theft.
• In simplest form it will act as a PIN.
• More advanced forms will be removable smart cards.
•3G terminals may later include other features to deter criminals.
• Identity establishment: voice recognition and iris scanning to verify user.
• Distress beacon: the terminal can phone the police to indicate it has been stolen, and
give them its current co-ordinates obtained from an in-built GPS.
22. 22
4.5 Increasing Terminal Time
•3G terminals will require low power technology and good batteries since:
• Multi-functional terminals will attract much use;
• Some services (e.g. MP3 audio) will be used for extended periods;
• Many features (e.g. browsers) will be SW enabled and need powerful CPUs & DSPs;
• The main customer complaint of current laptop PCs is their battery life.
•Power saving will need to be improved.
• System architecture and circuits.
•Power provision will need to be improved.
• Battery performance: depends on discharge rate, discharge depth, and temperature.
• Battery management: need charge control, cell protection and ‘fuel gauge’ indicators.
Management circuits can acquire, process, and communicate current operating
conditions, performance history, and pack-specific information.
• Battery types: options are nickel metal hydride (NiMH) and lithium ion (Li-ion).
NiMH & Li-ion offer good energy density, reduced cycle life, and high self-discharge rate,
but require a more complex charging algorithm and greater electrical and physical care.
23. 23
4.6 Improving the Look & Feel
•3G terminals will have to be small (100 cm3) and lightweight (100 g)
• Require more functionality in a single chip (design, integration and packaging).
• Must solve power problem (batteries and energy saving).
• Attempt to balance needs for a large screen in a small handset.
•3G terminals will need a superior interface.
• Microphone: must cope with conference calls.
• Loudspeaker: must be hi-fi quality.
• Screen: must be large and clear.
• Camera: must be small (10 x 10 x 7 mm has been achieved)
and ignore fluorescent flicker (100/120 Hz).
• Keypad: potentially redundant (replaced by touch sensitive
screen, handwriting interpreter, or voice recogniser).
25. 25
5.1 Conversational QoS Class
•What characterises a conversational traffic class?
• Always conducted between groups of human end-users.
• Low (400 ms) end-to-end delay (imposed by human perception).
• Normally symmetric traffic.
•Typical types of conversational class
• Voice:
AMR (adaptive multi-rate) codec to utilise
discontinuous activity and control bit rate to
trade-off quality with cell size/loading.
• Video telephony:
ITU-T Rec. H.324M for CS to match error-
resilience to link conditions;
ITU-T Rec. H.323 or IETF SIP for PS.
Siemens concept terminal
illustrating video telephony.
26. 26
5.2 Streaming QoS Class
•What characterises a streaming traffic class?
• A client-terminal can start displaying data before an entire file has been transmitted to it.
• A client-terminal collects bursts of data from a server and directs them as a steady
stream to an application which converts the data to sound/pictures.
• Normally asymmetric traffic, so is more robust to delay and jitter.
•Typical types of streaming class
• Web broadcast multimedia:
Target large audiences that connect to
via the Internet (i.e. slow).
• On-demand multimedia:
Target small audiences that connect
via a local intranet (i.e. fast).
Motorola concept terminal
illustrating on-demand multimedia.
27. 27
5.3 Interactive QoS Class
•What characterises an interactive traffic class?
• An client-user (live or machine) requests data on-line from a remote entity, and expects a
response within a certain time.
• Content is transparently transferred with a low bit error rate.
Ericsson concept terminal
illustrating web browsing.
•Typical types of interactive class
• Web browsing:
Push (spammed) or pull (requested).
• Network games:
Slower-paced games (e.g. chess).
28. 28
5.4 Background QoS Class
•What characterises a background traffic class?
• A client-user does not expect to receive data within a specific time.
• Content need not be transparently transferred, but must be delivered error-free.
•Typical types of background class
• Message services:
Electronic postcard or e-mail.
• Database services:
Remote logging.
Nokia concept terminal
illustrating an electronic postcard.
29. 29
6.1 Users and Usage
•The users and uses of 3G will be diverse.
• u-Information, n-Tertainment, @-Location services, e-Commerce & m-Communications.
•Trendy teenagers
• Call friends - whenever.
• Download and listen to the latest sounds on an MP3 player.
• Get a ticket for the latest gig at a keystroke, and pay for it with e-credits on their account.
•Powerful professionals
• Keep in contact with clients and the office - from anywhere in the world.
• Stop off at a motorway service station to review and change an on-line presentation.
• Reschedule a flight reservation during a meeting which looks set to overrun.
•Grey generation
• Alarm button to call family or emergency services gives a feeling of safety and security.
• Upload shopping list from fridge, visit supermarket and receive details of promotional
offers based on their consumer profile, and pay using their 3G credit account.
• Surf the Internet to find information for a college course project.
30. 30
6.2 u-Information
•3G terminals will be personalised.
• Organiser: calendar, diary and notepad.
• ID: security pass, driving licence and membership cards.
• Electronic keys: car, house, and safe.
• Information: health, and ‘how to …’
• Current affairs: news, sport and weather.
•Example scenario: ‘The Trial and the Try’
• It’s Saturday and I have to miss the big match to
take my girlfriend shopping.
• I subscribe to my team’s ‘scrum-down low-down’
news service, and at 3.30 my UE vibrates.
• I retrieve it and at the touch of a button see an
instant replay of the first try - just one minute
after touch-down.
31. 31
6.3 n-Tertainment
•3G terminals will give access to networked entertainment.
• Broadcast: TV and radio.
• On-demand: music and movies.
• Games: gambling and competitions.
•Example scenario: ‘Movie on the Move’
• I’m taking a coach one evening to visit some friends at
the weekend.
• To pass the time, I browse the latest movie trailers.
• The current blockbuster looks good, so I pay-to-view it
on my credit account.
• It’s streamed to my terminal and when I arrive at my
friends’ place we talk about ‘the part where …’
32. 32
6.4 @-Location Services
•3G terminals will provide location-based services.
• Navigation: directions to a destination.
• Travel information: congested roads, train schedules and flight arrivals/departures.
• Local information: a ‘Yellow Pages’ of nearby amenities.
• Security and safety: report position of a stolen vehicle or accident.
• Work-force management – co-ordinate agents (e.g. repair men) in the field.
•Example scenario: ‘Paris in the Spring’
• I decide to take a last minute break to Paris, and pack my bags.
• I arrive at CDG airport and use my UE to find a local hotel, and
book a room.
• In the taxi I talk to someone from the tourist information bureau,
and watch video clips of local attractions.
• Finally, having dropped off my luggage, I use my UE to select a
traditional French restaurant nearby, and get the directions to it.
33. 33
6.5 e-Commerce
•3G terminals will support electronic commerce.
• Banking: salary, bill payment, and alternative to cash/credit cards.
• Investing: stock tips, portfolio performance, stop-loss alerts, and on-line trading.
• Shopping: obtain details about items in a shop and pay for them with e-credit.
• Purchases: parking tickets, theatre tickets and drinks/snacks from vending machines.
• Advertising: sales catalogues (estate agents).
• Auctions:real-time on-line bidding.
•Example scenario: ‘Making Time vs Marking Time’
• I have a couple of minutes to spare while waiting for a friend.
• I buy a can of drink with my UE, and check my bank balance.
• My friend arrives, a little late, complaining she never has
time to do anything …
34. 34
6.6 m-Communications
•3G terminals will allow rich-media mobile communication.
• Video phone: video conferencing with optional recording for later viewing.
• Messaging: electronic postcards and e-mail.
• Remote monitoring: check on home and children while away.
•Example scenario: ‘Wish You Were Here’
• I’m visiting Niagara Falls - the scene is spectacular and
the noise incredible.
• I take a picture of myself against a backdrop of the falls,
record a ‘sound-bite’ of the roar of the water, and add a
message, “Wish you were here.”
• I email it to my friends in England.
36. 36
7.1 The Price and the Prize
•The costs for the 3G players in the UK are
• £22.5 Bn (actual) for 5 spectrum licences.
• £10 Bn (estimated) for network infrastructure.
•The potential profits are equally enormous
• US$23 Bn revenue anticipated from mobile e-commerce in Europe by 2003 (Durlacher).
• Exponential growth expected in web-access handsets (Nokia).
98 99 00 01
0
500
1000
Year
Million
Projected web handsets (Global)
02 03 04 05
37. 37
7.2 Prophets and Profits
•Companies could save money in 3G by reducing costs.
• Use a common network protocol.
• Take advantage of decentralised architectures.
•Companies could make money in 3G by increasing revenue.
• Increase market penetration by creating non-human users (e.g. cars).
• Charge a fee on all retail sales (as credit card companies do) rather than just providing
the channel.
• Develop partnerships with other companies (e.g. offer free travel reports for purchasing
petrol from a particular fuel supplier).
• Improve public confidence (e.g. offer reliable and secure services underwritten by a
trusted brand name).
•3G technology will merely be an enabler not an end in itself.
• Sandy Climan (MD Entertainment Media Ventures): “Content is the defining essential.
Those with content will set the pace.”
38. 38
8 Conclusions
•Potential
• Society: tailored to and altering the lifestyles of individuals.
• Business: emergence of partnerships between ‘pipe’ providers and content creators.
•Problems to be addressed
• Technological: several standard-variants must be supported, existing infrastructure
migrated, and new techniques implemented.
• Social: people won’t accept 3G until they are confident it is reliable and secure and are
happy with new ways of paying for new services.
• Commercial: companies must make a return on their enormous investments, by
achieving over 100% market penetration with novel content.
•Future
• Bernt Ostergaard (Giga Information Group): “It will be an interesting market that has
great potential for growth.”
39. 39
Further Reading
• ‘UMTS Mobile Communications for the Future’
Ed. Flavio Muratore
John Wiley & Sons Ltd.
ISBN 0-471-49829-7
• ‘WCDMA for UMTS - Radio Access for Third Generation Mobile Communications’
Ed. Harri Holma & Antti Toskala
John Wiley & Sons Ltd.
ISBN 0-471-72051-8
• ‘Spread Spectrum CDMA Systems for Wireless Communications’
Savo Glisic & Branka Vucetic
Artech House Publishers
ISBN 0-89006-858-5
