Ad hoc networking with rate-limited infrastructure: Generalized capacity scaling

Capacity scaling of a large hybrid network with unit node density, consisting of wireless ad hoc nodes, base stations (BSs) equipped with multiple antennas, and one remote central processor (RCP), is analyzed when wired backhaul links between the BSs and the RCP are rate-limited. We first derive the minimum backhaul link rate required to achieve the same capacity scaling law as in the infinite-capacity backhaul link case. Assuming an arbitrary rate scaling of each backhaul link, a generalized achievable throughput scaling law is then analyzed in the network based on using one of pure multihop, hierarchical cooperation, and two infrastructure-supported routing protocols, and moreover, information-theoretic operating regimes are identified. In addition, to verify the order optimality of our achievability result, a generalized cut-set upper bound under the network model is derived by cutting not only the wireless connections but also the wired connections.