Evolving Technologies for Terrestrial Wireless

1
Evolving Technologies for Terrestrial Wireless
Cellular Subscriber Growth Worldwide

• BAD 64046
• 26 February 2003

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Emerging 2.5G Cellular Data Transmission

• Video and other rich content requires higher data
  rates
• Unwilling to wait for 3G (third generation) data
  rates, some interim technologies are proposed by
  the industry
• These extend present 2G cellular standards, so
  are called 2.5G.

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CDMA Standards

• Standards for passing data on existing cellular
  wireless circuits
• IS-95B attains 64 Kbps by replacing voice channel
  overhead with a digital packet system
• IS-95B is not an overlay standard (as was CDPD,
  which uses free AMPS bandwidth)
• IS-95C is coming out now, supporting 144 Kbps for
  mobile computing
• All above are moving toward the cdma2000 3G
  standard

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High Speed Circuit-Switched Data

• HSCSD provides circuit-switched data transmission
  using multiple time slots on a GSM network
• 14.4 Kbps/slot
• Nokia (1998) has a four slot 57.6 Kbps system
• Works best with asymmetric application demands
• Major advantage of HSCSD requires no hardware
  changes -- just a base station software
  adaptation
• See http//www.ericsson.com/wireless/products/mob
  sys/gsm/subpages/wise/hscsd.shtml

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GPRS Synopsis

• GPRS facilitates instant connections whereby
  information can be sent or received immediately
  as the need arises. No dial-up modem connection
  is necessary. This is why GPRS users are
  sometimes referred to be as being "always
  connected". Immediacy is one of the advantages of
  GPRS (and SMS) when compared to Circuit Switched
  Data. High immediacy is a very important feature
  for time critical applications such as remote
  credit card authorization where it would be
  unacceptable to keep the customer waiting for
  even thirty extra seconds.
• Source http//www.mobileGPRS.com/gprs.asp?link1

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General Packet Radio Service

• GPRS provides packet based applications and
  services
• Uses multiple time slots of the GSM radio channel
• Raw rate of 24 Kbps/slot
• Phase 1 Multislot half duplex
• Max data rate of 4 x 14.4 Kbps
• Phase 2 Multislot full duplex
• All eight slots together give 115.2 Kbps

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HSCSD vs. GPRS

• HSCSD is an inefficient user of bandwidth because
  it marries one each slot to one and only one user
• GPRS mixes user data streams within a slot
• GPRS is directly compatible with TCP/IP because
  both are packet-switched
• HSCSD fits better with the installed PSTN base
• GPRS and HSCSD can coexist at the 2.5G level
• Presently, GPRS phones can only utilize four of
  the eight slots because of transmitter heating

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EDGE

• Enhanced Data Rates for Global Evolution
• Initiated by Ericsson
• Up to 384 Kbps mobile wide area coverage
• Uses advanced 8PSK modulation
• 3 bits sent per each transmitted symbol
• Same channel bandwidth and carrier structure as
  GSM, and uses GPRS infrastructure
• Commercial service possibly available in 2001

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Why Edge?

• The expected traffic increase due to Mobile
  Internet will put enormous demands on capacity in
  mobile networks.
• It is expected that in most mature markets, there
  will be a need for both enhanced 2G networks as
  well as 3G networks to cope with capacity
  demands.
• A major step in the evolution of General Packet
  Radio Service (GPRS), for instance, will be
  implementing EDGE, which will deliver speeds at
  384 kbit/s and more.

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3G Technologies

• Initially 1985 ITU Future Public Land Mobile
  Telecommunications System
• Has evolved into International Mobile
  Telecommunications-2000 (IMT-2000)
• ITU has allocated 1885 - 2025 MHz and 2110 - 2200
  MHz

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Goals of IMT-2000

• Increased efficiency and capacity
• New services available such as PC WANs
• Bandwidth on demand
• Increased flexibility, especially backwards
  compatibility
• Seamless roaming across dissimilar networks
• Integration of satellite services and fixed
  wireless with the cellular network
• 384 Kbps mobile, 2M fixed, 20 M fixed in later
  stage

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Moving Toward IMT-2000

• 15 proposals submitted in 1998
• Proposal unification process underway currently
• Main contenders are W-CDMA and cdma2000
• W-CDMA
• Wireless Code Division Multiple Access
• Backed by Japanese and European groups
• Backward compatible into GSM

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Moving Toward IMT-2000 (2)

• cdma2000
• Backed by U/S. and Korea
• Will require minimal hardware retrofit, at least
  initially
• First W-CDMA system in place in Japan by NTT
  Mobile Communications Network now
• Both W-CDMA and cdma2000 use orthogonal complex
  quadrature phase shift keying modulation and
  identical error correction schemes
• ITU has endorsed both standards, so global
  travelers will need dual-mode handsets

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Wireless Local Loop

• Goal is to replace the wire-based local loop
• Fixed WLL has four potential uses
• 1. Bring telephony to underserved parts of the
  world
• 2. Provide advanced services to businesses
• 3. Replace wireline services within office and
  residential areas
• 4. Competing alternative to copper local loops in
  liberalized markets

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WLL Growth Projections
WLL Growth Projections
Sourcehttp//www.iec.org/tutorials/wll/topic01.ht
ml?Next.x49Next.y16
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Where Is WLL Big?

• Extensive deployment in Asia, Eastern Europe, and
  other countries without adequate wireline
  services
• Offer rapid deployment, configuration, and
  adaptation
• Terrain-flexible
• Example 15 of all new customers in Poland are
  served by WLL technology

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WLL Also Cordless Systems

• WLL is sometimes also used to refer to cordless
  and low power mobile systems
• Dual use handsets can act as cordless telephone
  and revert to a public wireless network when out
  of range of the home base station
• Infrastructure costs very low compared to
  cellular

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Cordless System Realizations

• PACS (Personal Access Communications System)
  (U.S.)
• PWT (Personal Wireless Telecommunications) (U.S.)
• DECT (Digital Enhanced Cordless Telephone)
  (Europe)
• CT2 (Cordless Telephony Generation 2) (Singapore,
  Hong Kong, Canada, Europe)
• PHS (Personal Handyphone System (Japan)

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Radio Frequency Wireless Local Loop

• Project Angel
• 1997 ATT trial
• Uses neighborhood antenna mounted on a utility
  pole
• Method for ATT to offer local phone service
  while avoiding local phone charges
• Especially valuable in areas where ATT does not
  own a cable TV company
• One antenna serves 2000 homes subscribers need
  an 18 inch dish
• See http//news.cnet.com/news/0-1004-200-1581606.h
  tml

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Project Angel (cont.)

• Each household will have up to four phone lines
  and 512 Kbps Internet
• 1999 cost of deployment is about 1500/home
• Year 2000 trial in Dallas and Ft. Worth involving
  1.5 million homes
• Partial rollout 22 March 2000
• Full scale rollout in 2001

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WLL Equipment

• Qualcomm and Hitachi joint development agreement
  to achieve 2.4 Mbps data rate
• Qualcomm High Data Rate (HDR) technology to work
  within existing CDMA 1.25 MHz cellular networks
• Reserves part of the cellular spectrum for data
• Hitachi will build the hardware
• 2001 rollout targeted at neighborhoods where ADSL
  is unavailable

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WLL for Business Customers

• Teligent point to point microwave system
• 44.376 Mbps possible, but most real systems run
  at 1.5 Mbps (T1 speed)
• 12 inch dishes on business roofs link to local
  base station that interfaces to the PSTN
• Less costly than T1 line charges
• ATT owns 40 of Teligent

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Nonradio Local Loop

• Relies on lasers
• Susceptible to atmospheric conditions
• Lucent Wavestar OpticAir OLS System
• 2.5 Gbps data rate, up to 2 km
• Expecting 20 Gbps over 2 km
• See http//www.idg.net/crd_lucent_78408.html
• Terabeam Networks (Seattle)
• 1 Gbps
• Directors work through office windows
• Service rollout over the next three years

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Terabeam Technology
Source http//www.terabeam.com/pro/pro_pro_int.sh
tml
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Private Data Networks

• These are wide area, usually for specialized
  applications
• Do not provide voice
• Coverage areas are typically not divided
  geographically -- a major departure from cellular

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Mobiltex

• Ericcson introduction in Sweden in 1984
• Usage has spread to many countries, including the
  U.S.
• Managed by Mobiltex Operators Association
• Packet-switched network with max length of 512
  bytes packets are sent independently
• Each user has a unique access number
• Messages for a device are routed downward through
  the hierarchy
• BellSouth Mobile Data is largest U.S. -- focuses
  on e-mail and two-way pagers

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ARDIS

• Advanced Radio Data information Service
• Developed for IBM and Motorola use by their field
  organizations
• Offered commercially in 1990
• Data only 4.8 Kbps or 19.2 Kbps
• Covers 430 metropolitan areas
• Now switches automatically between terrestrial or
  satellite sources
• See, for example, http//www.motorola.com/cgiss/LA
  /products/systems/span/MobileWorkStat520.htm
• Trucking industry is a big customer

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Metricom

• Provides gateways to Internet, phone system, or
  corporate networks
• Service offered in several cities and on
  university campuses, some K-12 systems, and at
  the Sun Microsystems campus
• Numerous radio nodes attached to street lights,
  utility poles, or on rooftops
• Customer initiates communication
• Radio nodes are not all connected to wireline
• 28.8 Kbps secure, in 902 - 928 MHz range

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Point and Multipoint Distribution Services

• Rely on terrestrial microwave connections
• For video, voice, data service to individuals or
  subscriber groups
• One way or interactive
• Normally intended for fixed service

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Multichannel Multipoint Distribution Service

• MMDS
• Distributes video using 2600 - 2700 MHz range
• Transmitters send line of sight signals to small
  antennas at subscriber homes
• Recent conversion to digital enables about 100
  channels, with 300 channels and 40 mi radius
  expected at maturity

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MMDS Providers and Customers

• Fewer than 1M subscribers in North America, but
  trend is upward
• Attractive in developing countries because it
  saves the high cost of stringing coax
• Some providers are now offering Internet
  connectivity service at T1 downstream and 512
  Kbps upstream
• Cisco WT2700 Wireless Technology Suite uses
  multipath techniques
• Includes subscriber transceivers for about 500
  and hub equipment capable of supporting 3000
  subscribes for 150,000

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LMDS

• Local Multipoint Distribution Service
• 27.5 - 31.3 GHz
• Cell radius of 2 to 7 miles
• Needs about 30 transmitters to cover same area as
  one MMDS transmitter
• Competitive in performance with conventional CATV
• Provides data at 2 Gbps down and 200 Mbps up
• See http//www.wired.com/news/topstories/0,1287,18
  21,00.html

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LMDS Commercialization

• Speedus.com delivers video and data to customers
  in NYC to 6 inch dishes in their windows
• Residential service is about 60/month
• 48 Mbps Internet access
• Evolium LMDS
• 3.5 - 38 GHz cells several kilometers in
  diameter
• High speed voice and data to business and home
  offices
• Many very successful field trials in Europe

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Wireless LANs

• Scope of operation is usually confined to a
  single building or less
• Potentially huge emerging market, but it will
  grow slowly, as most LAN users have invested
  heavily in sophisticated cable plants

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Infrared Wireless LANs

• line of sight
• 1 meter distance limitation
• 30 degree aperture
• IrDA has developed a data communication standard,
  with most common speed 115.2 Kbps
• IrDA supported by Windows CE, Windows 95/98,
  Windows 2000, and Macintosh

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IEEE 802.11 Wireless LAN Standard

• All wireless LAN products that conform to this
  1997 standard are interoperable
• Non-compliant LANs will not compete successfully
• Operate in 910 - 928 MHz or 2.4 - 2.5 GHz bands
  (or IR)
• 802.11 is suitable for high data rate
  applications such as bar code readers, rental car
  return, warehouse merchandise tracking, hospital
  patient care, meter reading
• LANs separated by 20 to 30 miles can be tied
  together using appropriate antennas

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Home Radio Frequency (HomeRF)

• SWAP (Shared Wireless Application Protocol)
• PCs, peripherals, cordless phones can share data
  within a household range
• HomeRF Working Group leads the standards
  initiative
• Products for in-building shared high speed
  Internet access are planned
• 2.4 GHz spread spectrum 1 Mbps up to 11 Mbps
• See http//www.homerf.org/about.html