A Survey of Probabilistic Broadcast Schemes in Mobile Ad Hoc Networks

Probabilistic Broadcast Schemes

This algorithm proposed a novel density depends on a flooding scheme that a source sends a packet to all nodes in MANETs; it mainly based on the area density(dense, low), if the average of neighbors for the node x is larger than the threshold as a standard value, x takes “β type” and gets a high probability that rebroadcast without delay; if the average of neighbors for x is smaller than the threshold, x takes “α type” and gets a small probability that waits a time duration before rebroadcast; this approach interested in broadcast with less routing overhead and collision but the bandwidth may be lost if the intensity is limited in two levels (dense, low).

This approach proposed new route discovery algorithm named Efficient and Dynamic Probabilistic Broadcasting (EDPB) concerns to solve the Broadcast Storm problem AODV, it is implementing simulation on Global Mobile Simulator GPS; this algorithm depends on the knowledge and probabilistic that dynamically adjusted based on both local neighbors and changing the neighbors of node; initially the node x is hearing a message then getting number of neighbors (n) for x to compare with average node (n bar) typically in general network, the result either it implies the probability is higher (n < n bar) in low density or it implies the probability is lower (n > n bar) in high density; it supports main performance evaluation metrics such as reducing end-to-end delay, but it can't cover type of zones such as the density of medium zone Reference.

This algorithm depends on getting the information that is collecting by broadcasting “Hello” packet every second for only one hop to calculate the number of the nodes N in the networks, and the minimum average (avg min) of neighbors and also maximum average of neighbors (avg max); then it compares N with avg min, if (N < avg min) this implies N in low sparse region and the probability is higher if (avgmax ≤n<avg) this implies N in medium sparse ; if (avg≤n<avgmax) this implies medium density; if (n≥avgmax) this implies N in high density. This algorithm decreased of a huge amount of flooding packets and delay of RREQ packets, so it consequently keeps the time and cost, however can't support all Routing protocol and HELLO packets do not provide accurate information about the number of neighbors can pray to my god to marry, maybe happen impossible.