Ad hoc Networks
What is an Ad hoc Network? An Ad hoc Network is a wireless infrastructureless network in which nodes communicate with one another without any central control. In contrast to WiFi network, an infrastructure based network, nodes in an Ad hoc Network may deliver packets delivery packets independently or according to an algorithm that maximizes an objective function. The objective function could be probability of successful transmission or a soft queueing delay bound. In contrast to wired network, ad hoc network transmits packet by wireless broadcast. The contentious nature of such wireless transmissions coupled with numerous issues related to mobile nodes make packet delivery challenging.
In a wireless contention channel, a packet is successfully transmitted iff it is the only transmission. Failure can be due to more than one simultaneous transmissions within its normal effective range or due to the hidden terminal problem. If transmission spans more than one hop, the problem of packet failure will be compounded due to possible contention failure at any hop along the selected path. Therefore, there are two problems to be solved. The first is to ensure that there is only one packet transmission within the effective range of the first receiver and the second, to repeat this requirement at every receiver along the selected multihop path. The problem is highly complex and possibly intractable unless a distributed scheduling algorithm becomes available. A comprehensive solution to this problem will allow an implementation of an efficient wireless adhoc network.