星期日, 2月 26, 2006

802.11

802.11 Metropolitan Wireless Business Models
  • Taipei Model
  • Bay Area Model
  • Philadelphia Model

802.11 Protocol
  • 802.11b/a/g/n
  • 802.11 MAC (pp. 2-88~2-107)
  • 802.11 PCF & DCF
    802.11 RTS & CTS
    802.11 QoS
  • animations (two Applets about CSMA/CA Simulations)

Industry & Products
於

2 則留言:

  1. Yao Jen週六 12月 22, 04:27:00 下午 GMT+8

    brand: Wi-Fly
    subscription: flat rate, monthly charge, 399/mo
    applications: access
    management: gov outsourced to a private company

    utility: water, power, local phone company (wire)

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  2. Yao Jen週六 12月 22, 04:27:00 下午 GMT+8

    Google
    operator: Google , Earthlink
    subscription: free access, ad

    FON
    AP manufactured by Accton at Taiwan
    subscription: free access, AP accessible to others

    Taipei
    outsourced ISP

    Philadelphia
    gov-owned ISP

    Wi-Fi is contention-based, non FCFS
    voice needs constant bit rate
    Ethereal, Skype packet, silence suppression, 37% talk spurts, 63% silent

    Quality of Service, QoS
    delay
    <100 ms excellent
    150-250 acceptable
    >250 ms unacceptable

    jitter
    variance between packets

    IEEE 802.11e

    AP to AP

    deassociation, reassociation 50ms
    Application layer delay> 5sec

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