The Research On Broadcasting Algorithms Of Ad Hoc Network

With the rapid development of wireless network technology,wireless network has become an indispensable part of people's daily life.Ad-hoc network has become the focus of research in recent years because of self-organization,without fixed infrastructure and all the nodes setting networking spontaneously.Broadcasting is a very important manner of wireless ad-hoc network.Broadcasting is not only the basis of path found in ad-hoc network,but also can be used to send special message to the entire network such as the failure of one of the routing.So broadcasting algorithm has been praised by the majority of scholar's attention.The simplest way of broadcasting algorithm is flooding.But the traditional flooding methods can produce a large number of redundant forwarding so that it could take additional conflict even network congestion.This kind of situation is called the broadcast storm.For solving the broadcast storm problem,this paper proposes location based space-covered broadcasting algorithm and two hop neighbors table based broadcasting algorithm in Ad Hoc network.Aim at the lower successfully rate,higher redundant forwarding nodes and transmission delay by broadcasting storm,this paper proposes location based space-covered broadcasting algorithm in ad-hoc network firstly.The algorithm selects next jump forwarding nodes,optimizes the spatial distribution of the forwarding nodes.reduces redundant forwarding node number according to node location of the ideal disk cover model.The algorithm do not generate additional bandwidth and storage overhead because of without information of neighbor nodes.This paper simulates for Location Based Space-Covered Broadcasting Algorithm in different node numbers and different transmission radius.Simulation experiment results shows that the two broadcasting algorithms in this paper can reduce the number of forwarding nodes and the times of forwarding,reduces the transmission delay with high successfully sending rate.Aim at the problem which some broadcasting algorithm need GPS to locate for nodes in ad-hoc network.this paper proposes two hop neighbors table based broadcasting algorithm in Ad Hoc network.The algorithm gets the local topology information by sending hello packets each node and creats two neighbor tables.then chooses the next-hop forwarding nodes according to the selection rules.The allocated nodes sends the broadcasting packets to accomplish the broadcasting.The selection rules of forwarding nodes is the key to the algorithm,it introduces the concept in-degree and out-degree of node and uses them to allocate next hop nodes so that make sure the forwarding nodes which is chose could cover two hop nodes completely.So the algorithm is not only could restrain redundant forwarding effectively.but also could guarantee the complete coverage of network.This paper simulates for 2-hop Neighbors Table Based Broadcasting Algorithm in different node numbers,different transmission radius and different movement speed of nodes respectively.Simulation experiment results shows that the two broadcasting algorithms in this paper can reduce the number of forwarding nodes,the times of forwarding and reduce the transmission delay with high successfully sending rate.