wang laye schrieb: > Hi, > I am simulating a QoS Routing Protocol,in this protocol,the > available bandwidth of node is caculate according: > Available Bandwidth=Total Bandwidth - Reseved Bandwidth - Bandwith In Use > My question is:In C++, to a mobile node,How can i measure (or > caculate) the bandwidth in use? > Any suggestion is appreciated! > You should explain your network a little more, are you suing APs or an ad hoc network?
Determining the available bandwidth in a wireless network is quite complicated because it depends on the behavior of the nodes around you (even if they are out of communication range). I used the following approach: instead of bandwidth I used "air time" (to account for different transmission speeds), that is the time a node utilizes the wireless channel in its region for a transmission. To reserve air time I used a beacon-based multi-hop reservation protocol. Additionally, to measure "lost" air time, that is air time than cannot be used because of interference from nodes out of communication range (or e.g. a microwave oven) I measured the time a packet to be transmitted spends in the output buffer of the transmitter. Changes in this time indicate a change in the available air time. You see, the task you are going to solve cannot simply be accomplished by calculating a value out of available variables. If you have more questions, don't hesitate to ask me. Daniel.
