Dynamic Packet Scheduler Optimization in Wireless Relay Networks

TL;DR

This paper develops an optimal dynamic packet scheduling policy for wireless relay networks, demonstrating that balancing queue lengths at each time slot is optimal under symmetrical conditions, with a practical low-overhead implementation.

Contribution

It proves the optimality of a queue balancing policy in WRNs with symmetrical connectivity and provides a low-overhead algorithm for its implementation.

Findings

Queue balancing policy is optimal in symmetrical WRNs.

The proposed algorithm is low-overhead and practical.

Optimal policy minimizes queue size cost functions.

Abstract

In this work, we investigate the optimal dynamic packet scheduling policy in a wireless relay network (WRN). We model this network by two sets of parallel queues, that represent the subscriber stations (SS) and the relay stations (RS), with random link connectivity. An optimal policy minimizes, in stochastic ordering sense, the process of cost function of the SS and RS queue sizes. We prove that, in a system with symmetrical connectivity and arrival distributions, a policy that tries to balance the lengths of all the system queues, at every time slot, is optimal. We use stochastic dominance and coupling arguments in our proof. We also provide a low-overhead algorithm for optimal policy implementation.