Capacity of Social-Aware Wireless Networks with Directional Antennas

The widespread of smart phones has brought new social-aware features to wireless networks. Users prefer to forward traffic to their social contacts in social-aware networks, which is highly different from the traditional uniform traffic pattern. To this end, we analyze a social-aware wireless network, which is modeled by the social contacts between nodes, and explore its impact on network throughput capacity. We present that it can refine social contacts, thus improving the network capacity. Moreover, directional antennas are applied to further enhance the capacity performance, which can reduce the interference brought by other simultaneous communications. We derive the throughput capacity for social-aware networks with single-beam and multi-beam directional antenna, respectively. For single-beam directional antenna, we prove that when wireless networks are dominated by traffics of short-distance social contact, the throughput capacity can be promoted from order of Θ (1/θ²}n log\,n)^1/2) to Θ({1}/{θ² log\,n)^1/2). In addition, when the beamwidth θ is at order of Ω ({1}/{({log\,n)^1/2, the throughput capacity is a constant. Thus, the wireless network is scalable. For multi-beam antennas, we prove that when sidelobe gain G_s is at order of $o(G_m) , where G^m is main lobe gain, compared with the single-beam case, the network capacity can achieve the order of Θ (1/θ₂ log\,n)^1/2.