Wireless Communication Class Note

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Wireless CommunicationClass Note
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References

• Book
• Introduction to Mobile Network Management by
  Yi-Bing Lin
• Web Sites
• http//www.uwcc.org
• http//villagenet.com/imta/
• http//www.gsm.org
• http//www.gsmworld.com
• http//www.wirelessdata.org/
• http//www.pcsdata.com

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Journal References

• IEEE Personal Communications Magazine
• ACM Mobile Computing Communication Review
• IEEE Network
• IEEE Communications Magazine

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Contacts

• ???
• [phone] or [phone] ext 2807
• wshih_at_cs.nthu.edu.tw

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Outline

• Wireless Communication Overview
• Identifies the essential functions and basic
  components
• A System View
• Examines several specific systems
• GSM, CDMA, PHS, DECT, Iridium
• Studies service platforms
• Wireless Information Services
• VoiceDataMobility
• SMS, USSD, HSCSD, GPRS, 3G

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Personal Communications System (PCS)

• A personal communications system provides people
  with wireless access to information services.
• 6 S in PCS
• services, sets, spectrum, standards, systems,
  subscribers

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Conventional Call
Reference Fig 1.4 on Page 9, in Wireless Personal
Communications Systems
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Cellular Call

• Channels, Cells
• Initialization
• Service Requests
• Paging
• Channel Assignments
• Handoff

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Cellular Architecture
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Control/ Information Flow

• Reference Figure 1.13, on Page 18, in Wireless
  Personal Communications Systems

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Challenges

• Mobility
• Location management, roaming
• Ether
• Access
• Channel Impairment/Fading
• Bandwidth
• Privacy Security
• Energy

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Evolution of Personal Communications

• Voice Data -gt PCS
• Voice Cellular Cordless
• Data Mobile Computing Paging

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High-Tier vs. Low-Tier Wireless Systems

• High-Tier
• Serving a highly mobile population by means of
  sophisticated high-power radios
• Cell diameters can exceeded 10 km
• Terminals are capable of radiating on the order
  of 1 watt
• Base station antennas can be higher than 50
  meters and radiate tens of watts
• Low-Tier
• Serving subscribers moving at pedestrian speeds
• Base stations separates by less than 500 meters
  outdoors, and less than 30 meters indoors
• Transmitter powers are one to two orders of
  magnitude lower
• Outdoor antennas are around 10 meters

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Cellular

• Radio Transmission
• first generation analog systems to second
  generation digital technologies
• Network Infrastructure
• Published standards over proprietary

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Cellular

• Terminal Equipment
• Consumer preference over vehicle-mounted
  telephones
• Enhanced Wireless Services
• Expanding their scope to cover services
  originally delivered by paging networks and
  wireless data systems.
• Examples AMPS, GSM, DAMPS, CDMA

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Advanced Mobile Phone System (AMPS)

• Used in North America First -generation analog
  cellular system, available since 1983 Developed
  by Bell Labs.
• Adopts FDMA
• Voice channels are carried by different radio
  frequencies.
• A total 50 MHz in 824-849 MHz 869-894 MHz
• Divided into 832 frequency channels 416
  downlinks and 416 uplinks
• Frequency Reuse A frequency may be reused by
  cells in different clusters

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AMPS

• The scope of AMPS specification is limited to the
  air interface between subscriber equipment and
  base station radios. Signaling systems that link
  base stations to switches and switches to other
  switches are proprietary in North America
• A signaling standard for communications between
  mobile switches IS-41, for roaming management

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Global System for Mobile Communications (GSM)

• Developed by European Community, at 900 MHz
• Including transmission specification as well as
  signaling specification, international roaming is
  the focus.
• Radio transmission is based on TDMA (time divided
  multiple access),

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DAMPS (IS-136)

• Operate in the same spectrum used by existing
  AMPS
• Used TDMA
• Three voice channels coding rate 7.95 Kb/s
• Using IS-41 for mobility management.

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CDMA (IS-95)

• CDMA allows many users to share a common channel
  for transmission, and the user signals are
  distinguished by spreading them with different
  codes.
• Speech coding rate us 8Kb/s IS-41 is used.

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Cordless Telephones

• Residential cordless phones replacing the
  telephone line cord with radio equipment that
  transmits signals between a telephone and the
  pair of telephone company wires within a
  residence.
• 50 MHz in North America 900 MHz in Europe 300
  MHz in Japan

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Low-Tier Systems

• Goal
• low service price small, lightweight terminals
  with long battery life
• radio transmission 32 kb/s
• Wireless extensions of other telephone systems
  (like PBX) CT2, DECT,
• Public networks offering wide-area coverage PHS,
  PACS

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Cordless Telephone, Second Generation (CT2)

• Allocated 40 FDMA channels with a 32 Kb/s
• Base-to-handset signals and handset-to-base
  signals are transmitted in the same frequency
  with different time-slots
• In public telepoint, call delivery is not
  supported

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Digital European Cordless Telecommunications
(DECT)

• Go beyond telephony and deliver a wide range of
  communications services to wireless terminals
• Focus on interconnections between DECT and other
  networks, like PSTN, ISDN, GSM, LAN, and PBX

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Mobile Computing

• From desktop machines to laptops, and to PDA

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Paging

• Beepers, caller phone numbers, messages, e-mail
• Two-way pagers