Transmission Capacities for Overlaid Wireless Ad Hoc Networks with Outage Constraints

TL;DR

This paper analyzes how two coexisting wireless networks can optimize their transmission capacities under outage constraints, revealing that slight increases in outage probability can significantly boost overall spectrum efficiency.

Contribution

It provides a quantitative analysis of transmission capacities for primary and secondary networks sharing spectrum, introducing a tradeoff framework based on outage constraints and Poisson node distributions.

Findings

Allowing small outage increases boosts total capacity.

Secondary network controls interference to primary.

Asymptotic analysis reveals capacity tradeoffs.

Abstract

We study the transmission capacities of two coexisting wireless networks (a primary network vs. a secondary network) that operate in the same geographic region and share the same spectrum. We define transmission capacity as the product among the density of transmissions, the transmission rate, and the successful transmission probability (1 minus the outage probability). The primary (PR) network has a higher priority to access the spectrum without particular considerations for the secondary (SR) network, where the SR network limits its interference to the PR network by carefully controlling the density of its transmitters. Assuming that the nodes are distributed according to Poisson point processes and the two networks use different transmission ranges, we quantify the transmission capacities for both of these two networks and discuss their tradeoff based on asymptotic analyses. Our results show that if the PR network permits a small increase of its outage probability, the sum transmission capacity of the two networks (i.e., the overall spectrum efficiency per unit area) will be boosted significantly over that of a single network.