[ns] how to get used-bandwidth of a wireless node in ns

[uglystone]

Hi everyone,

I am trying to add admission control mechanism in dsr ,so I need to know
a node's bandwidth which has occupied at any moment. here ,there is a
method. in dsr, enable every flow to carry occupied bandwidth by itself.
we can compute a node's bandwidth which has occupied through integrating
all flows' occupied bandwidth which pass through the node. 
But,I don't know any better one,so I would like to get some advice.
thanks!

     zhaojunmin