Utility Maximization in Wireless Backhaul Networks with Service Guarantees

TL;DR

This paper addresses utility maximization in wireless backhaul networks by modeling them as trees, proposing novel scheduling algorithms, and developing scalable distributed solutions to meet SLAs involving delays and throughput.

Contribution

It introduces a new pinwheel scheduling algorithm and a distributed approach for utility maximization in wireless backhaul networks with tree topologies.

Findings

Simple round-robin schedules can be optimal in symmetric trees.

The new algorithm significantly expands schedulable sets in polynomial time.

The distributed method has linear complexity in tree depth.

Abstract

We consider the problem of maximizing utility in wireless backhaul networks, where utility is a function of satisfied service level agreements (SLAs), defined in terms of end-to-end packet delays and instantaneous throughput. We model backhaul networks as a tree topology and show that SLAs can be satisfied by constructing link schedules with bounded inter-scheduling times, an NP-complete problem known as pinwheel scheduling. For symmetric tree topologies, we show that simple round-robin schedules can be optimal under certain conditions. In the general case, we develop a mixed-integer program that optimizes over the set of admission decisions and pinwheel schedules. We develop a novel pinwheel scheduling algorithm, which significantly expands the set of schedules that can be found in polynomial time over the state of the art. Using conditions from this algorithm, we develop a scalable, distributed approach to solve the utility-maximization problem, with complexity that is linear in the depth of the tree.