A neighbor knowledge and velocity-based broadcast scheme for wireless ad hoc networks

A neighbor knowledge-based broadcast scheme is proposed to reduce the latency for wireless ad hoc networks, yet keeping the overhead at a reasonably low level and fulfilling the reliability. In the scheme, few Hello messages are interchanged to collect one-hop neighbor information. The collected information is used to calculate the neighbor density, the ratio, and the number of one-hop uncovered neighbors, upon which the rebroadcast probability and delay are adjusted adaptively. The way that the rebroadcast probability and delay are defined in neighbor knowledge-based broadcast scheme reduces the transmission overhead and restrains the traffic aggregation effectively. Next, a velocity-based data distribution mechanism is proposed and extended to neighbor knowledge-based broadcast scheme to further reduce the latency, forming neighbor knowledge and velocity-based broadcast scheme. It is stipulated that few higher-velocity nodes are employed with bigger probability to rebroadcast the incoming message. The performance of the schemes is evaluated by the simulation under diverse network configurations. The results show that they outperform the existing broadcast schemes in overhead and especially in average end-to-end delay. Compared with flooding, they reduce the overhead by 88.4% and the average end-to-end delay by 88.9% at most.