Quality of information maximization in two-hop wireless networks

An information collection problem in a wireless network with random events is considered. Wireless nodes report on each event using one of multiple reporting formats. Each format has a different quality and uses a different number of bits. Delivering all data in the highest quality format can overload system resources. The goal is to make intelligent format selection and routing decisions to maximize time-averaged information quality subject to network stability. Lyapunov optimization theory can be used to solve such a problem by repeatedly minimizing the linear terms of a quadratic drift-plus-penalty expression. To reduce delays, a novel extension of this technique that preserves the quadratic nature of the drift minimization while maintaining a separable decision structure is proposed. Also, paths are restricted to 1 or 2 hops to avoid high queuing delay. The resulting algorithm can push average information quality arbitrarily close to optimum, with a trade-off in average delay. The algorithm compares favorably to the basic drift-pluspenalty scheme in terms of backlog and delay.