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  • 1. 1An Introduction toThird Generation Mobile CommsSignal Processing & Multimedia CourseSummer 2001
  • 2. 2Contents•Overview• Origins• Concepts•Requirements• Networks• Terminals•Uses• Classes• Scenarios•Implications• Business• Conclusions
  • 3. 3Overview1 Origins2 Concepts
  • 4. 41.1 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 onfair, 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 InternationalTelecommunications Union (ITU) of a single CDMA third generation standard thatencompasses three optional modes of operation.”
  • 5. 51.2 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 & TDDformed from ETSI, T1P1, TTC, CWTS, ARIB & TTA.• 3GPP2 for MCformed from TTA & TR45.5.Single Carrier Multi-Carrier MC FDD TDDUWC-136 DECT cdma2000 UTRA FDD UTRA TDDTD-SCDMACDMATDMAIMT-2000
  • 6. 62.1 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 signalin 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.fA Af
  • 7. 72.2 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 beable 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 ourGoodmorningGut e n t agBuongiorno
  • 8. 82.3 Downlink•Downlink (time-aligned)• 1 scrambling code (Cs) per cell.• 1 or more channelization code (Cch#) per UE.CsCch1 Cch3Cch2
  • 9. 92.4 Uplink• Uplink (not time-aligned)• 1 scrambling code (Cs#) per UE.• 1 or more channelization codes per UE.Cs1Cs2Cs3
  • 10. 102.5 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-Bwould 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. 112.6 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.
  • 12. 12Requirements3 Networks4 Terminals
  • 13. 133.1 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. 143.2 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 forEurope and North America.
  • 15. 153.3 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 canshare 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. 163.4 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 willenable 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 withdifferent service creation/management tools on various networks.• Providers will want to use off-the-shelf applications to create a new service once anddeploy it across a unified network, not custom-craft each service for each network.• Subject to international roaming agreements 3G will allow network access fromanywhere on the globe and always using the same terminal.
  • 17. 173.5 Strategy of Roll-out•Roll-out strategies will vary around the globe.• Existing Japanese PHS network is under severe strain and the Japanese governmentwill 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 butadditional 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. 184.1 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 makethem harder to protect against soft-attack.
  • 19. 194.2 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 wirelessdetachable keypad.terminals shown areAll conceptdesigns proposed by Ericsson.
  • 20. 204.3 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 conducte-commerce transactions anywhere in the world.• Interoperable software and the complexity demanded of a feature-rich terminal mayleave them vulnerable to viruses and hacking.• Adnan Al-Adnani (Panasonic): “It is a major concern for operators and they won’tintroduce 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 userspass 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 againstrogue 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. 214.4 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 astrongbox 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 towhat extent.”•3G terminals will initially include a USIM (User Services Identity Module) todeter 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, andgive them its current co-ordinates obtained from an in-built GPS.
  • 22. 224.5 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 operatingconditions, 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. 234.6 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 sensitivescreen, handwriting interpreter, or voice recogniser).
  • 24. 24Uses5 Classes6 Scenarios
  • 25. 255.1 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 utilisediscontinuous activity and control bit rate totrade-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 terminalillustrating video telephony.
  • 26. 265.2 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 steadystream 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 tovia the Internet (i.e. slow).• On-demand multimedia:Target small audiences that connectvia a local intranet (i.e. fast).Motorola concept terminalillustrating on-demand multimedia.
  • 27. 275.3 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 aresponse within a certain time.• Content is transparently transferred with a low bit error rate.Ericsson concept terminalillustrating web browsing.•Typical types of interactive class• Web browsing:Push (spammed) or pull (requested).• Network games:Slower-paced games (e.g. chess).
  • 28. 285.4 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 terminalillustrating an electronic postcard.
  • 29. 296.1 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 promotionaloffers based on their consumer profile, and pay using their 3G credit account.• Surf the Internet to find information for a college course project.
  • 30. 306.2 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 totake 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 aninstant replay of the first try - just one minuteafter touch-down.
  • 31. 316.3 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 atthe weekend.• To pass the time, I browse the latest movie trailers.• The current blockbuster looks good, so I pay-to-view iton my credit account.• It’s streamed to my terminal and when I arrive at myfriends’ place we talk about ‘the part where …’
  • 32. 326.4 @-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, andbook 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 atraditional French restaurant nearby, and get the directions to it.
  • 33. 336.5 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 hastime to do anything …
  • 34. 346.6 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 andthe 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 amessage, “Wish you were here.”• I email it to my friends in England.
  • 35. 35Implications7 Business8 Conclusions
  • 36. 367.1 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 0105001000YearMillionProjected web handsets (Global)02 03 04 05
  • 37. 377.2 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 providingthe channel.• Develop partnerships with other companies (e.g. offer free travel reports for purchasingpetrol from a particular fuel supplier).• Improve public confidence (e.g. offer reliable and secure services underwritten by atrusted 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. 388 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 infrastructuremigrated, and new techniques implemented.• Social: people won’t accept 3G until they are confident it is reliable and secure and arehappy with new ways of paying for new services.• Commercial: companies must make a return on their enormous investments, byachieving over 100% market penetration with novel content.•Future• Bernt Ostergaard (Giga Information Group): “It will be an interesting market that hasgreat potential for growth.”
  • 39. 39Further Reading• ‘UMTS Mobile Communications for the Future’Ed. Flavio MuratoreJohn Wiley & Sons Ltd.ISBN 0-471-49829-7• ‘WCDMA for UMTS - Radio Access for Third Generation Mobile Communications’Ed. Harri Holma & Antti ToskalaJohn Wiley & Sons Ltd.ISBN 0-471-72051-8• ‘Spread Spectrum CDMA Systems for Wireless Communications’Savo Glisic & Branka VuceticArtech House PublishersISBN 0-89006-858-5