Technion Extensions of the JiST/SWANS Simulator


Maintained by Gabriel Kliot (


JiST/SWANS simulator is a Java-based discrete event simulator for Wireless Ad Hoc networks developed in Cornell University (
JiST is a high-performance discrete event simulation engine that runs over a standard Java virtual machine. SWANS is a  Scalable Wireless Ad hoc Network Simulator that runs on top of the JiST engine.
The supporting community of JiST/SWANS is continuously growing.

On this page, we provide a set of extensions to JiST/SWANS simulator created at the Technion - Israel Institute of Technology. These extensions include bug fixes, new functionally we have developed, as well as simply sharing our experience working with  JiST/SWANS.

  1. Signal Interference models - explanation and bug fixes
  2. PHY setup - how to set PHY parameters and how to measure the effective transmission range
  3. Animation - using Javis or NAM animators to graphically display simulation scenarios
  4. How to add support for multiple radios
  5. Running JiST with Java 1.5
  6. Bug fixes:
    1. Bug in Mac802_11  - wrong backoff counting  
    2. Bug in Mac802_11  - wrong duplicate message elimination handling
    3. Bug in RandomWalk mobility model - wrong bouncing off the walls
    4. Bug in Location.Location2D - wrong handling of node location if is exactly on the border of two bins
    5. Bug in trans.CircularBuffer - bug in the function retrieveBytes().
    6. Bug in trans.TcpSocket - wrong value used for maximum congestion window.
    7. Bug in trans.TransTcp - DROP_PROBABILITY should be set to zero.
  7. Suggestions, ideas, and my general experiences with developing code for network simulators
    1. Making your simulations run faster


Thank you note:
I would like to thank everyone who contributes to this project by reporting bugs:


There is a number of other teams who actively work on extending and improving JiST/SWANS. Some of them are listed below. Send me an email if you want to be added to this list:

  1. JiST/SWANS Portal from Ulm university - fixes, improvements, VANET mobility models and Geographic routing
  2. Jist/SWANS portal of Paul Kiddie from University of Birmingham
  3. SWANS++ - Extensions to the Scalable Wireless Ad-hoc Network Simulator, developed by David Choffnes from Northwestern University. It currently includes a mobility model for wireless vehicular ad-hoc network (VANET) simulations, a number of routing protocols, and a visualization tool. Source Forge SWANS++ project.


Gabi Kliot