Network Simulator ns2

Ns-2 is a discrete event simulator targeted at networking research.

802.11 Support

The existing 802.11 support in ns-2 is disapointing for a number of reasons.

• No beacons, management packets etc
• No support for vendor specific extensions like
  • transmission power control
  • dynamic channel allocation
• No cross-channel fading
• Purushothaman, Roy - Technical Report - IEEE 802.11 implementation issues/bugs in ns2
• Schmidt-Eisenlohr et al - Bug Fixes on the IEEE 802.11 DCF Module of the Network Simulator ns-2.28

Interference Model

• Interference is only calculated between two packets. If the original received power is high enough, the frame will not be discarded, if it's too low, the frame will be discarded. The ratio of received to interfering power is compared to CPThresh and thus it's decided, whether the frame is discarded or not.

Fork by Mathieu Lacage

A new 802.11 module based on a fork of ns-2 around mid-september 2005. Latest release was released in September 2005. The fork is not supported anymore.

Improvements

• ET/SNRT/BER-based PHY models
• 802.11a multirate
• 802.11e HCCA and EDCA

Problems

• Incompatible with legacy scripts
• Does not use logging functionality of ns2
• No collisions between different network links????

Link: http://yans.inria.fr/ns-2-80211/

Patch by Marco Fiore

Adds the following features to ns-2.29

• realistic channel propagation by Wu Xiuchao
• ricean propagation model by Ratish J. Punnoose
• SNOOPy calendar scheduler by David X. Wei
• 802.11 bug fixes by Felix Schmidt-Eisenlohr
• multiple data transmission rates support by Marco Fiore
• Adaptive Auto Rate Fallback (AARF) by Marco Fiore.

Link: http://www.telematica.polito.it/fiore/

Patch by Ilango Purushothaman

• beacon support
• ongoing work!

Link: http://ee.washington.edu/research/funlab/802_11/802_11_beacon.tar.gz

Patch by Mike Moreton

• based on ns-2.26 (feb 2003)
• Support for 802.11e
• Original download location is offline

IEEE 802.11e EDCA Simulation Model for ns-2

Link: http://www.tkn.tu-berlin.de/research/802.11e_ns2/

Based on ns-2.28 (feb 2005)

Extensions:

• EDCA
  • no HCCA
  • no block ACK
• contention free bursting (CFB) / TXOP bursting

Bugfixes:

• introduces seperate SIFS timer, such that different timers for deferal (DIFS) and inter-packet times are semantically different,
• stops deferal whenever the medium becomes busy,
• proper computation of NAV,
• proper setting / resetting of NAV.

Missing:

• Rate Adaptation

Stanford's 802.11e implementation for ns/2

Link: http://mosquitonet.stanford.edu/software/802.11e/

Qiang Ni's EDCF/HCF implementations for ns/2

Link: http://www-sop.inria.fr/planete/qni/Research.html

IEEE 802.11e HCCA module for ns-2

Link: http://info.iet.unipi.it/~cng/ns2hcca/

• Patch for ns-2.29 (Nov 2005)

IEEE 802.11 PCF support for ns-2.1b8

Link: http://www.sm.luth.se/~dugdale/index/software.shtml/

IEEE 802.11 Power Saving Model (PSM) support for ns-2.1b8a

Link: http://www.cag.lcs.mit.edu/~ronny/wireless_psm/readme.html

• Simulates standard 802.11 PSM protocol, or the Bounded Slowdown (BSD) protocol