Multicast Capacity of Wireless Ad Hoc Networks with Infrastructure Support

In this paper, we study the multicast capacity of wireless ad hoc networks with infrastructure support. The network under study is termed as hybrid wireless network, where L-Maximum-Hop resource allocation strategy is adopted. There are n uniformly deployed normal wireless nodes and m regularly placed base stations dividing the network region into m cells. We show that the maximum capacity O(n(1/2)/k(1/2)(log n)W-1/2(1)) + O(mW(2)) is achieved when the hop number L = Theta (n(1/4)/(k(1/4) (log n)(3/4))), with the number of destinations k = O(a(2)/r(2)), where a is the side length of network region and r is transmission range of wireless terminals. This result provides a meaningful guide for the design of hybrid wireless networks. Moreover, we demonstrate that it is more efficient to adopt Infrastructure Mode than Ad Hoc Mode when k = Omega(a(2)/r(2)), because infrastructure nodes can cover the whole cell and broadcast to nodes more efficiently. In this case, maximum capacity is O (W-1) + O (mW(2)), when L = Theta(1). Furthermore, we reveal that the per-node capacity does not vanish to zero only if the number of base stations m = Omega(n).