vdesmond / arq-protocols

Implementation of Automatic Repeat reQuest (ARQ) protocols in python

arq-protocols (and other stuff)

This repository contains implementation of 3 protocols:

• Stop and Wait ARQ
• Go Back N ARQ
• Selective Repeat ARQ

And also some bonus stuff including:

• CSMA/CA Simulation

How to run

1. Clone this repository
2. (optional) Create a virtual environment before running.
   1. Install some additional python packages: pip install coloredlogs verboselogs
   2. If you want to use the logging module only, you can modify the code under # Configure Logging for every file.
3. Run sender and receiver in seperate tabs/windows.
4. The command line arguments are as follows:
   
   
   1. Stop and Wait ARQ
      Sender: python sw_sender.py <PORT> <LOSS_PROB> <ACK_TIMEOUT> <MESSAGE>
      Receiver: python sw_receiver.py <PORT> <LOSS_PROB>
      
      
   2. Go Back N ARQ
      Sender: python gbn_sender.py <PORT> <SEQ_NO_BIT_WIDTH> <LOSS_PROB> <ACK_TIMEOUT> <MESSAGE>
      Receiver: python gbn_receiver.py <PORT> <SEQ_NO_BIT_WIDTH> <LOSS_PROB>
      
      
   3. Selective Repeat ARQ
      Sender: python sr_sender.py <PORT> <SEQ_NO_BIT_WIDTH> <LOSS_PROB> <ACK_TIMEOUT> <MESSAGE>
      Receiver: python sr_receiver.py <PORT> <SEQ_NO_BIT_WIDTH> <LOSS_PROB>
      
      
   4. CSMA/CA Simulation
      CSMA/CA has been implemented on top of Stop and Wait ARQ
      Sender station: python sender_station.py <PORT> <LOSS_PROB> <ACK_TIMEOUT> <CHANNEL_BUSY_PROB> <IFS> <MAX_K> <MESSAGE>
      Base Station: python base_station.py <PORT> <LOSS_PROB>
      

Additional Notes

• Make sure PORT and SEQ_NO_BIT_WIDTH is same for both sender and receiver
• ACK_TIMEOUT is in milliseconds.
• The window length for Go Back N and Selective Repeat ARQ is calculated as (2 ** SEQ_NO_BIT_WIDTH) - 1 and 2 ** (SEQ_NO_BIT_WIDTH - 1) respectively
• For CSMA/CA, IFS is in milliseconds.

Additional Notes (Ubuntu)

• Added single script to run all files. Use ./arq.sh -h for help.
• If you use zsh, change -- bash to -- zsh in lines 71, 74, 77. If you use any other terminal, make appropriate changes

Examples

Stop and Wait ARQ

Go Back N ARQ

Selective Repeat ARQ

CSMA/CA Simulation

UEC1604 - Communication Networks, SSN College of Engineering