[ns] HOW TO CHECK CONGESTION LEVEL in WIRELESS NETWORK?HELP

[antonis antoniou]

I want to use 802.11 to create a wireless network.
In each node i want to check congestion level(queue or channel sampling)and 
according to these values react by rerouting the traffic....

Can any one help????I will really appreciate your answer on:
1. how to check queues or channel sampling
2. reroute the traffic

: i am  new on ns2