Improvement of the capacity of wireless networks by optimizing communication distance

As the number of nodes increases, the capacity of ad-hoc wireless networks is constrained by radio interference. Especially when a source node cannot directly communicate with its destination node, every packet has to travel through one or more intermediate nodes. The throughput decreases as the number of relayed hop count increases. To effectively use the limited radio resources, we propose a scheme that a node avoids radio interference among its adjacent nodes by appropriately controlling its transmission power. In this case, the network capacity is expected to quite improve when each node sets its communication distance to physical distance to the next intermediate node. However, this may be difficult to realize in practical environments. In this paper, we examine the optimal communication distance to maximize the network capacity when all nodes take the same communication distance. Results showed that the communication distance to maximize the network capacity depended on the node density. We further showed that the network capacity was independent of the node density. In addition, the proposed scheme could improve the network capacity up to 2.1 times higher than the traditional scheme.