The Simulation And Research About Topology Control Algorithms In Wireless Ad Hoc Networks

Wireless Ad Hoc networks are self-organized without any immobile basic communication facilities, whose characteristics are wirelessness, multi-hop and mobility. They are useful for some places where communication networks are to be built temporarily, which is taking on a wide foreground. The battery power is limited in Ad Hoc networks, so it's important to save power using. It is the main topic for the researches about topology control to find good algorithms to reduce the consumption of the node's transmitting power, so as to save energy, prolong the networks'lifetime and optimize the performance of the networks.This paper has done researches on two topology control algorithms mainly. One is based on cluster, CLTC, in intracluster the cluster head carries out an algorithm which is to make the cluster strong connected and in interclusters the transmitting power of those border nodes between different clusters is controlled by the cluster head, and this step is to make the interclusters strong connected. The other is based on a cone degree, CBTC; it increases the transmitting power continuously until there is at least one neighbor in anyα-cone around each node. As for CLTC, this paper takes the three-dimension terrain into consideration and the algorithm is written in C language. Then the network is two-connected. For convenient observation, a program is written to display the topology's changing status under VC IDE. As for CBTC, this paper considers that the nodes'limited energy will be consumed when the power is increasing. Then the research about the relationship between the lifetime and the power increasing steps, the packet length and the packets'transmitting speed is done. From the research's result, it can be concluded that, CBTC algorithm can save the energy consumption for dense topology, while for the sparse topology it can't reduce the energy consumption. In the end, this paper simulates the topology control's efficiency in real networks through OPNET environment. From the result, it can be concluded that, CBTC algorithm improves the networks'throughput and reduces the frames'media access delay in MAC layer.