Local versus global power adaptive broadcasting in ad hoc networks

Abstract — In many ad hoc deployments, making broad-casting, a critical function component, power efficient is extremely important. Current power-adaptive approaches proposed for broadcasting, can be grouped into a) central-ized or omniscient schemes, and b) decentralized or local-ized schemes. The latter assume only local neighborhood information. Due to the absence of global information, lo-calized algorithms may not produce optimal or near-optimal solutions. On the other hand, global knowledge is not typi-cally available to nodes and may be extremely expensive to disseminate. In this paper, we examine the importance of the lack of global information on the performance of local-ized approaches. Towards this, we perform extensive sim-ulations and compare the performance of localized power adaptive broadcasting with the performance of the well-known Broadcast Incremental Power or BIP, an omniscient algorithm. We analyze the behaviors of the two protocols and identify the reasons for the differences in behavior. We observe that while global state does provide better perfor-mance in terms of energy efficiency, the localized scheme outperforms the global scheme in terms of the latency in-curred in the broadcast. Based on the observed behavioral traits of the two protocols, we suggest changes by which the energy consumption with the localized scheme is reduced by as much as 20%, while incurring almost no penalty in terms of latency. I