Study of Power Consumption in a Cooperative Wireless Network

A cooperative wireless network is defined to be a network where nodes cooperate in routing and/or improving thequality of transmission of each other’s packets [1]-[5]. Thecooperation is especially useful when the channel between a pair of nodes (source and destination) is in a deep shadow-fading state. In this situation increasing the power level may either not resolve the problem or be too power consuming, while generating interference for other receivers on the same channel. A cooperating node, which has good propagation channels to both the source and the destination, may be used to relay the packets between them. This paper presents the comparison of theaverage amounts of power consumed by nodes in a standard wireless network that uses single-hop transmission and a cooperative wireless network that uses two-hop transmission. It is shown that under certain conditions the ratio of the average power consumptions in the two networks, when N cooperating nodes on average are available for each node, can be approximated by k ln N + q. The constants k and q are related to the propagation channel. For a Nakagami fading channel with parameter m, k =1/ lnm and q=1, while for a shadowing channel with standard deviation σdB, k =σdB/ √ π and q = 0.23σdBdB.