[ns] calculating bandwith occupation

[Bilel Romdhani]

hi,
to calculate the bandwith ocupation on the channel, i extended the
mac-802.11.cc but when i try to calculate the occupation for txSate (when i
declare type = Packet_type(p) to know the type of my packet) i have
segmentation fault.

PS : the same function used on rxState there is no pb.

Plz if u have an idea or solution let me know sooooooon
thanks