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CWNA Guide to Wireless LANs, Second Edition. Chapter Twelve Personal, Metropolitan, and Wide Area Wireless Networks. Objectives. Define a wireless personal area network List the technologies of a wireless metropolitan area network Describe the features of a wireless wide area network

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cwna guide to wireless lans second edition

CWNA Guide to Wireless LANs, Second Edition

Chapter Twelve

Personal, Metropolitan, and Wide Area Wireless Networks

objectives
Objectives
  • Define a wireless personal area network
  • List the technologies of a wireless metropolitan area network
  • Describe the features of a wireless wide area network
  • Discuss the future of wireless networking

CWNA Guide to Wireless LANs, Second Edition

wireless personal area networks
Wireless Personal Area Networks
  • Wireless networks classified into four broad categories:
    • Wireless personal area network (WPAN): Hand-held and portable devices; slow to moderate transmission speeds
    • Wireless local area network (WLAN): i.e., IEEE 802.11a/b/g
    • Wireless metropolitan area network (WMAN): Range up to 50 kilometers
    • Wireless wide area network (WWAN): Connects networks in different geographical areas

CWNA Guide to Wireless LANs, Second Edition

wireless personal area networks continued
Wireless Personal Area Networks (continued)

Figure 12-1: Wireless network distances

CWNA Guide to Wireless LANs, Second Edition

wireless personal area networks continued5
Wireless Personal Area Networks (continued)

Figure 12-2: Point-to-point transmission

CWNA Guide to Wireless LANs, Second Edition

wireless personal area networks continued6
Wireless Personal Area Networks (continued)

Figure 12-3: Point-to-multipoint transmission

CWNA Guide to Wireless LANs, Second Edition

wireless personal area networks continued7
Wireless Personal Area Networks (continued)
  • WPANs encompass technology designed for portable devices
    • PDAs, cell phones, tablet or laptop computers
    • Low transmission speeds
  • Three main categories:
    • IEEE 802.15 standards
    • Radio frequency ID (RFID)
    • IrDA

CWNA Guide to Wireless LANs, Second Edition

wpans ieee 802 15 1 bluetooth
WPANs: IEEE 802.15.1 (Bluetooth)
  • Bluetooth uses short-range RF transmissions
    • Users can connect wirelessly to wide range of computing and telecommunications devices
    • Rapid and ad hoc connections between devices
  • 802.15.1 adapted and expanded from Bluetooth
    • Designed for area of about 10 meters
    • Rate of transmission below 1 Mbps
  • Two types of 802.15.1 network topologies
    • Piconet
    • Scatternet

CWNA Guide to Wireless LANs, Second Edition

wpans ieee 802 15 1 continued
WPANs: IEEE 802.15.1 (continued)
  • Piconet: When two 802.15.1 devices come within range, automatically connect
    • Master: Controls wireless traffic
    • Slave: Takes commands from master
    • Piconet has one master and at least one slave
  • Active slave: Connected to piconet and sending transmissions
  • Parked slave: Connected but not actively participating

CWNA Guide to Wireless LANs, Second Edition

wpans ieee 802 15 1 continued10
WPANs: IEEE 802.15.1 (continued)

Figure 12-4: Piconet

CWNA Guide to Wireless LANs, Second Edition

wpans ieee 802 15 1 continued11
WPANs: IEEE 802.15.1 (continued)

Figure 12-5: Slave device detected by a master device

CWNA Guide to Wireless LANs, Second Edition

wpans ieee 802 15 1 continued12
WPANs: IEEE 802.15.1 (continued)
  • Devices in piconet can be in one of five modes:
    • Standby: Waiting to join a piconet
    • Inquire: Device looking for devices to connect to
    • Page: Master device asking to connect to specific slave
    • Connected: Active slave or master
    • Park/Hold: Part of piconet but in low-power state
  • Scatternet: Group of piconets in which connections exist between different piconets
  • 802.15.1 uses FHSS

CWNA Guide to Wireless LANs, Second Edition

wpans ieee 802 15 1 continued13
WPANs: IEEE 802.15.1 (continued)

Figure 12-6: Scatternet

CWNA Guide to Wireless LANs, Second Edition

wpans ieee 802 15 1 continued14
WPANs: IEEE 802.15.1 (continued)

Table 12-1: Comparison of 802.15.1 speed

CWNA Guide to Wireless LANs, Second Edition

wpans ieee 802 15 3
WPANs: IEEE 802.15.3
  • Created in response to limitations of 802.15.1
    • High-rate WPANs
  • Two main applications:
    • Video and audio distribution for home entertainment systems
      • High-speed digital video transfer
      • High-density MPEG2 transfer between video players/gateways and multiple HD displays
      • Home theater
      • PC to LCD projector
      • Interactive video gaming
    • High speed data transfer

CWNA Guide to Wireless LANs, Second Edition

wpans ieee 802 15 3 continued
WPANs: IEEE 802.15.3 (continued)
  • Differences between 802.15.3 and 802.15.1
    • Quality of Service (QoS)
    • Security
    • High data rates
    • Spectrum utilization
    • Coexistence

Table 12-2: IEEE 802.15.3 security modes

CWNA Guide to Wireless LANs, Second Edition

wpans ieee 802 15 3 continued17
WPANs: IEEE 802.15.3 (continued)
  • 802.15.3a: Will support data transfers up to 110 Mbps between max of 245 devices at 10 meters
    • Ultrawideband (UWB)
    • Intended to compete with USB 2.0 and FireWire
  • IEEE 802.15.3b task group working on improving implementation and interoperability of 802.15.3
  • IEEE 802.15.3c task group developing alternative physical layer standard that could increase speeds up to 2 Gbps

CWNA Guide to Wireless LANs, Second Edition

wpans ieee 802 15 4
WPANs: IEEE 802.15.4
  • Sometimes preferable to have low-speed, low-power wireless devices
    • Size can be dramatically reduced
  • IEEE 802.15.4 standard addresses requirements for RF transmissions requiring low power consumption and cost

Table 12-3: IEEE 802.15.4 data rates and frequencies

CWNA Guide to Wireless LANs, Second Edition

wpans ieee 802 15 4 continued
WPANs: IEEE 802.15.4 (continued)
  • ZigBee Alliance: Industry consortium that promotes 802.15.4 standard

Figure 12-7: ZigBee and IEEE 802.15.4

CWNA Guide to Wireless LANs, Second Edition

wpans radio frequency id rfid
WPANs: Radio Frequency ID (RFID)

Figure 12-8: RFID tag

CWNA Guide to Wireless LANs, Second Edition

wpans radio frequency id continued
WPANs: Radio Frequency ID (continued)
  • Passive RFID tags: No power supply
    • Can be very small
    • Limited amount of information transmitted
  • Active RFID tags: Must have power source
    • Longer ranges/larger memories than passive tags

Table 12-4: RFID tags

CWNA Guide to Wireless LANs, Second Edition

wpans irda
WPANs: IrDA
  • Infrared Data Association
  • IrDA specifications include standards for physical devices and network protocols they use to communicate
  • Devices communicate using infrared light-emitting diodes
    • Recessed into device
    • Many design considerations affect IrDA performance

CWNA Guide to Wireless LANs, Second Edition

wpans irda continued
WPANs: IrDA (continued)

Figure 12-9: IrDA diodes in device

CWNA Guide to Wireless LANs, Second Edition

wpans irda continued24
WPANs: IrDA (continued)
  • IrDA drawbacks:
    • Designed to work like standard serial port on a personal computer, which is seldom used today
    • Cannot send and receive simultaneously
    • Strong ambient light can negatively impact transmissions
    • Angle and distance limitation between communicating devices

CWNA Guide to Wireless LANs, Second Edition

wireless metropolitan area networks
Wireless Metropolitan Area Networks
  • Cover an area of up to 50 kilometers (31 miles)
  • Used for two primary reasons:
    • Alternative to an organization’s wired backhaul connection
      • i.e., T1, T3, T4 lines
        • Fiber Optics
      • Very expensive to install backhaul connections
      • Often less expensive to use a WMAN to link remote sites

CWNA Guide to Wireless LANs, Second Edition

wireless metropolitan area networks continued
Wireless Metropolitan Area Networks (continued)
  • Used for two primary reasons (continued):
    • Overcome last mile connection
      • Connection that begins at a fast Internet service provider, goes through local neighborhood, and ends at the home or office
      • Slower-speed connection
        • Bottleneck

CWNA Guide to Wireless LANs, Second Edition

wireless metropolitan area networks free space optics
Wireless Metropolitan Area Networks: Free Space Optics
  • Optical, wireless, point-to-point, line-of-sight wireless technology
    • Able to transmit at speed comparable to Fiber Optics
    • Transmissions sent by low-powered IR beams
  • Advantages compared to fiber optic and RF:
    • Lower installation costs
    • Faster installation
    • Scaling transmission speed
    • Good security
  • Atmospheric conditions can affect transmission

CWNA Guide to Wireless LANs, Second Edition

wireless metropolitan area networks local multipoint distribution service lmds
Wireless Metropolitan Area Networks: Local Multipoint Distribution Service (LMDS)
  • LMDS provides wide variety of wireless services
    • High-frequency, low-powered RF waves have limited range
    • Point-to-multipoint signal transmission
      • Signals transmitted back are point-to-point
    • Voice, data, Internet, and video traffic
    • Local carrier determines services offered
  • LMDS network is composed of cells
    • Cell size affected by line of site, antenna height, overlapping cells, and rainfall

CWNA Guide to Wireless LANs, Second Edition

wireless metropolitan area networks lmds continued
Wireless Metropolitan Area Networks: LMDS (continued)

Figure 12-11: LMDS cell

CWNA Guide to Wireless LANs, Second Edition

wireless metropolitan area networks multichannel multipoint distribution service mmds
Wireless Metropolitan Area Networks: Multichannel Multipoint Distribution Service (MMDS)
  • Many similarities to LMDS
    • Differs in area of transmission
    • Higher downstream transmission, lower upstream transmission, greater range
  • In homes, alternative to cable modems and DSL service
  • For businesses, alternative to T1 or fiber optic connections
  • MMDS hub typically located at a very high point
    • On top of building, towers, mountains

CWNA Guide to Wireless LANs, Second Edition

wireless metropolitan area networks mmds continued
Wireless Metropolitan Area Networks: MMDS (continued)
  • Hub uses point-to-multipoint architecture
    • Multiplexes communications to multiple users
    • Tower has backhaul connection
  • MMDS uses cells
    • Single MMDS cell as large as 100 LDMS cells
  • Receiving end uses pizza box antenna
  • Advantages:
    • Transmission range, cell size, low vulnerability to poor weather conditions
  • Still requires line-of-site, not encrypted

CWNA Guide to Wireless LANs, Second Edition

wireless metropolitan area networks ieee 802 16 wimax
Wireless Metropolitan Area Networks: IEEE 802.16 (WiMAX)
  • High potential
    • Can connect IEEE 802.11 hotspots to Internet
    • Can provide alternative to cable and DSL for last mile connection
    • Up to 50 kilometers of linear service area range
    • Does not require direct line of sight
    • Provides shared data rates up to 70 Mbps
  • Uses scheduling system
    • Device competes once for initial network entry

CWNA Guide to Wireless LANs, Second Edition

wireless metropolitan area networks ieee 802 16 continued
Wireless Metropolitan Area Networks: IEEE 802.16 (continued)
  • Currently addresses only devices in fixed positions
    • 802.16e will add mobile devices to the standard
  • IEEE 802.20standard: Sets standards for mobility over large areas
    • Will permit users to roam at high speeds
  • WiMAX base stations installed by a wireless Internet service provider (wireless ISP) can send high-speed Internet connections to homes and businesses in a radius of up to 50 km (31 miles)

CWNA Guide to Wireless LANs, Second Edition

wireless wide area networks wwans
Wireless Wide Area Networks (WWANS)
  • Wireless networks extending beyond 50 kilometers (31 miles)
  • Two primary technologies:
    • Digital cellular telephony
    • Satellites

CWNA Guide to Wireless LANs, Second Edition

digital cellular telephony
Digital Cellular Telephony
  • Two keys to cellular telephone networks:
    • Coverage area divided into cells
      • Cell transmitter at center
      • Mobile devices communicate with cell center via RF
      • Transmitters connected to base station,
      • Each base station connected to a mobile telecommunications switching office (MTSO)
        • Link between cellular and wired telephone network
    • All transmitters and cell phones operate at low power
      • Enables frequency reuse

CWNA Guide to Wireless LANs, Second Edition

digital cellular telephony continued
Digital Cellular Telephony (continued)

Figure 12-13: Frequency reuse

CWNA Guide to Wireless LANs, Second Edition

satellites
Satellites
  • Satellite use falls into three broad categories:
    • Acquire scientific data, perform research
    • Examine Earth
      • Military and weather satellites
    • “Reflectors”
      • Relay signals
      • Communications, navigation, broadcast

CWNA Guide to Wireless LANs, Second Edition

satellites continued
Satellites (continued)
  • Satellite systems classified by type of orbit:
    • Low earth orbiting (LEO): Small area of earth coverage
      • Over 225 satellites needed for total coverage of earth
      • Must travel very fast
    • Medium earth orbiting (MEO): Larger area of coverage than LEO
      • Do not need to travel as fast
    • Geosynchronous earth orbiting (GEO): orbit matches earth’s rotation
      • “Fixed” position
      • Very large coverage area

CWNA Guide to Wireless LANs, Second Edition

satellites continued39
Satellites (continued)

Figure 12-14: LEO coverage area

CWNA Guide to Wireless LANs, Second Edition

the future of wireless networks
The Future of Wireless Networks
  • IEEE 802.11 subcommittees currently at work:
    • 802.11d:Supplementary to 802.11 MAC layer
      • Promote worldwide use of 802.11 WLANs
    • 802.11f: Inter-Access Point Protocol (IAPP)
      • Will assist with faster handoff from one AP to another
    • 802.11h: Supplement to MAC layer to comply with European regulations for 5 GHz WLANs
    • 802.11j: Incorporates Japanese regulatory extensions to 802.11a standard
    • 802.11s: Defines a mesh wireless network
      • Devices configure themselves and are intelligent

CWNA Guide to Wireless LANs, Second Edition

summary
Summary
  • WPANs encompass technology that is designed for portable devices, typically PDAs, cell phones, and tablet or laptop computers at transmission speeds lower than the other types of networks
  • The IEEE 802.15 standards address wireless personal area networks
  • RFID is not a standard but is a technology that uses RF tags to transmit information
  • IrDA technology uses infrared transmissions to transmit data at speeds from 9,600 bps to 16 Mbps

CWNA Guide to Wireless LANs, Second Edition

summary continued
Summary (continued)
  • FSO is an optical, wireless, point-to-point wireless metropolitan area network technology
  • LMDS can provide a wide variety of wireless services, including high-speed Internet access, real-time multimedia file transfer, remote access to local area networks, interactive video, video-on-demand, video conferencing, and telephone
  • MMDS has many of similarities to LMDS, yet has a longer distance range

CWNA Guide to Wireless LANs, Second Edition

summary continued43
Summary (continued)
  • The IEEE 802.16 (WiMAX) standard holds great promise for providing higher throughput rates for fixed location and mobile users
  • Wireless wide area network (WWAN) technology encompasses digital cellular telephony and satellite
  • The future of wireless networks is hard to predict, but most experts agree that wireless networks will be faster, more global, and easier to use in the years ahead

CWNA Guide to Wireless LANs, Second Edition