Gain analysis of cooperative broadcast in two-dimensional wireless networks

Energy accumulation is an approach to reducing the power consumption of broadcast. In conventional approaches, a node can decode the message if the received power from a single transmission is above a threshold. In contrast, in the cooperative approach based on energy accumulation, a node can decode the message if the sum of the received powers from any set of transmissions exceeds the threshold. An important question is how much energy can be saved in broadcast if energy accumulation is employed. Since employing energy accumulation adds extra design complexities, answering this question can help in deciding whether or not it should be implemented. Previously, it was shown that this saving is limited in linear wireless networks, irrespective of the network size, and the location of the nodes in the network. In this work, however, we show that this saving can increase with the network size in two-dimensional networks. Also, despite the fact that both problems of cooperative and non-cooperative broadcast with minimum energy are NP-hard, we establish a bound on the maximum saving that can be obtained.