Throughput-Delay Scaling for Two Mobile Overlaid Networks

In this paper, we study the throughput and delay scaling laws of two coexisting mobile networks. By considering that both the primary and secondary networks are mobile and move according to random walk model, we propose a multi-hop transmission scheme. Based on the assumption that the secondary node can help to relay the primary packet, we show that the secondary network can achieve the same throughput and delay scaling laws as in stand-alone network D_s(m)=Θ(mλ_s(m)). Furthermore, for primary network, it is shown that the throughput-delay tradeoff scaling law is given by D_p(n)=Θ(√(n log n λ_p(n))), when the primary node is chosen as relay node. If the relay node is a secondary node, the scaling law is D_p(n)=Θ(√(n^β log n λ_p(n))), where β>;1. The novelties of this paper lie in: i) Detailed study of the delay scaling law of the secondary network in the complex scenario where both the primary and secondary networks are mobile; ii) The impact of buffer delay on the primary and secondary networks due to the presence of preservation region. We explicitly analyze the buffer delay and obtain an expression as D^II(S_R)(m)=Θ(1/√(n^β-1 a_s(m))).