Introduction to WiMax

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Introduction to WiMax
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References

• IEEE 802.16-2004 (802.16REVd)
• IEEE 802.16-2005 (802.16e)
• Intels Whitepapers, 2004 (http//www.intel.com/te
  chnology/itj/2004/volume08issue03/)
• IEEE Standard 802.16 A Technical Overview of
  the WirelessMAN Air Interface for Broadband
  Wireless Access, C. Eklund et al., IEEE
  Communication Magazine, June 2002
• Broadband Wireless Access with 802.16/WiMax
  Current Performance Benchmarks and Future
  Potential, A. Ghosh et al., IEEE Communication
  Magazine, Feb 2005
• Wireless Communication Standards A Study of
  IEEE 802.11, 802.15, and 802.16, T. Cooklev,
  2004
• Computer Network, Tenenbaum

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WiMax

• WiMAX ????????????? Worldwide Interoperability
  for Microwave Access
• ??????????????????????????????????????????????????
  ????????? (Point-to-Multipoint)

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??????????????????? WiMAX

• IEEE 802.16-2001 ??????????????????????????? Line
  of Sight (LoS)?????????????????????? 1.6 4.8
  ???????? ??????????????????????????????? 10-66
  GHz
• IEEE 802.16a ?????????????????????????????????
  2-11 GHz ??????????????????????????????????????
  IEEE 802.16 ??????????????????????????????????????
  ???????? Non-Line-of-Sight (NLoS)
  ?????????????????????????????? ???? ??????,
  ?????,?????? ?,????? ??? ?????????????????????????
  ???????????????????????????????????????
  ???????????????????????????? 50 ????????
  ???????????????????????????????????????????? 75
  Mbps (????????????????) ??????????????????????????
  ???????????????????????????? ??1 (T1-type)
  ?????????? 60 ?????????? ?????????????????????????
  ????????? DSL?????????????????????????????????????
  ?????????????????????????????? ???????????????????
  ?????????????????????????
• IEEE 802.16-2004 ?????????????????????????????????
  ???????????? ??????????? ??? IEEE 802.16a,
  802.16c, 802.16d ?????????????????????????? 2-66
  GHz ??????????????????? 30 ???? ?????????? 50
  ????????
• IEEE 802.16e ?????????????????????????????????????
  ????????????????????????????????? ???? ????????
  ?????? ??????? ????????????? 2-6 GHz
  ??????????????????? 1.6 4.8 ????????
  ????????????????????????????????????????????????
  ?????????????????????? ?

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802.16 Standards History

• First standard based on proprietary
  implementations of DOCSIS/HFC architecture
  in wireless domain

• Original fixed wireless broadband air Interface
  for 10 66 GHz Line-of-sight only,
  Point-to-Multi-Point applications

• Extension for 2-11 GHz Targeted for
  non-line-of-sight, Point-to-Multi-Point
  applications like last mile broadband access

802.16 Amendment WiMAX System Profiles 10 - 66 GHz

• Adds WiMAX System Profiles and Errata for 2-11 GHz

• MAC/PHY Enhancements to support subscribers
  moving at vehicular speeds

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Applications of 802.16 Standards
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??????????????

• Base station (BS) ???????????? ???????????????????
  ?????? Cell site ?????????????????????? Wired
  Internet Backbone
• Subscriber Station (SS) ???? ????????????
  ??????????????????????????????????????????????????
  ????? CPE (Customer Premises Equipment)
  ?????????? Hub ??????? ???????????????????????????
  ??????????? ? ????????????????????????????????????
  ???????????????? ??????? ????????????????????????-
  ?????????????????????? ????????????????????????

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Broadband Wireless

• The 802.16 Protocol Stack
• The 802.16 Physical Layer
• The 802.16 MAC Sublayer Protocol
• The 802.16 Frame Structure

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The 802.16 Protocol Stack

• The 802.16 Protocol Stack.

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The 802.16 Physical Layer

• The 802.16 transmission environment.

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Physical Layer Summary
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Channel Characteristics

• 10-66 GHz
• Very weak multipath components (LOS is required)
• Rain attenuation is a major issue
• Single-carrier PHY
• 2-11 GHz
• Multipath
• NLOS
• Single and multi-carrier PHYs

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The 802.16 Physical Layer (2)

• Frames and time slots for time division duplexing.

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The 802.16 MAC Sublayer Protocol

• Service Classes
• Constant bit rate service
• Real-time variable bit rate service
• Non-real-time variable bit rate service
• Best efforts service

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The 802.16 Frame Structure

• (a) A generic frame. (b) A bandwidth request
  frame.