Impact of Heterogeneity and Secrecy on the Capacity of Wireless Sensor Networks.

This paper investigates the achievable secrecy throughput of an inhomogeneous wireless sensor network. We consider the impact of topology heterogeneity and the secrecy constraint on the throughput. For the topology heterogeneity, by virtue of percolation theory, a set of connected highways and information pipelines is established; while for the secrecy constraint, the concept of secrecy zone is adopted to ensure secrecy transmission. The secrecy zone means there is no eavesdropper around the legitimate node. The results demonstrate that, if the eavesdropper's intensity is λ(e)= o((log n)(-(3δ-4)/(δ-2))), a per-node secrecy rate of Ω [formula: see text] can be achieved on the highways, where δ is the exponent of heterogeneity, n and n(v) represent the number of nodes and clusters in the network, respectively. It is also shown that, with the density of the eavesdropper λ(e) = o((log(n Φ ̲ ))(-2)), the per-node secrecy rate of Ω (√(Φ ̲ /n)) can be obtained in the information pipelines, where Φ ̲ denotes the minimum node density in the network.