Wireless Phy in ns-3

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The goal of this project is to define a common interface to a set of PHY-level models for wireless transmission mediums spanning a large range of wireless transmission systems:

  • 802.11a/b/g
  • wimax
  • satellite
  • ...

The following sections try to define:

  • the characteristics of each wireless transmission system we want to capture
  • various models to capture these characteristics



  • carrier frequency: b/g: 2.4GHz, a: 5GHz
  • signal spread: 20Hz
  • 802.11b transmission modes:
    • 1Mb/s: DBPSK + barker PN sequence
    • 2Mb/s: DQPSK + barker PN sequence
    • 5.5Mb/s: CCK + code spread
    • 11Mb/s: CCK + code spread
  • 802.11a transmission modes:
    • 6Mb/s: BPSK + FEC 1/2
    • 9Mb/s: BPSK + FEC 3/4
    • 12Mb/s: DBPSK + FEC 1/2
    • 18Mb/s: DBPSK + FEC 3/4
    • 24Mb/s: QAM16 + FEC 1/2
    • 36Mb/s: QAM16 + FEC 3/4
    • 48Mb/s: QAM64 + FEC 2/3
    • 54Mb/s: QAM64 + FEC 3/4

The MAC layer needs modelization of the following features:

  • interference among multiple stations transmitting at the same time
  • resistance of different transmission modes to interference: the 54Mbs mode should resits less than the 6Mbs mode
  • signal propagation: attenuation and delay

So, a typical PHY would be caracterized by one of 5 states:

  • TX: transmitting some bits
  • SYNC: receiving some bits
  • IDLE: not doing anything, medium is not busy
  • BUSY: not doing anything, medium is busy
  • SLEEP: sleeping, not listening to the medium for status

The condition for BUSY state is precisely defined for 802.11: it is called CCA state detection. There are multiple CCA modes but the basic mode is based on the total energy measured at the antenna.


  • some people might need multiple SLEEP states: some SLEEP states are deeper than others, take longer to recover from, etc.
  • some people want to modelize antenna directionality. I have zero idea on how to modelize this.

Models which fulfill these needs: