Infrastructure support increases the capacity of ad hoc wireless networks

In ad hoc wireless networks, one of the hottest research directions has been to increase the throughput capacity scaling with respect to the number of nodes n. Gupta and Kumar (2000) introduced a fixed random network model and showed that the throughput per source-destination pair is Theta(1/root nlogn) when the network is coordinated by a centralized entity. Grossglauser and Tse (2001) introduced a mobile random network model and showed that a source-destination pair acquires a constant throughput of Theta(1) assuming that delays incurred by mobile nodes with low mobility are tolerable. In this paper, we consider the capacity of ad hoc wireless networks with infrastructure support. Although Grossglauser-Tse mobile network model enables Theta(1) per-node throughput scaling, the mobility assumption may be too unrealistic to be accepted in some practical situations. One of the key observations we acquired is that the infrastructure support plays the same role played by the mobility in the Grossglauser-Tse model. We show that nodes can utilize the randomly located infrastructure support instead of mobility when nodes are nearly static. In this case, we show that the per-node throughput of Theta(1) is still achievable when the number of access points grows linearly with respect to the number of nodes. Furthermore., we show that there is additional per-node throughput improvement of Theta(1) when nodes are mobile.