On the Optimization and Stability of Sectorized Wireless Networks

TL;DR

This paper investigates the capacity and stability of sectorized wireless mesh networks, proposing optimization algorithms for node sectorization that significantly enhance network flow and adaptability under dynamic traffic conditions.

Contribution

It introduces a novel capacity characterization, an efficient distributed optimization algorithm with approximation guarantees, and explores dynamic sectorization strategies for improved network performance.

Findings

Sectorization increases network capacity and flow extension ratio.

The proposed algorithms achieve near-optimal sectorization with a 2/3 approximation ratio.

Dynamic sectorization strategies improve stability and capacity under unknown traffic loads.

Abstract

Future wireless networks need to support the increasing demands for high data rates and improved coverage. One promising solution is sectorization, where an infrastructure node is equipped with multiple sectors employing directional communication. Although the concept of sectorization is not new, it is critical to fully understand the potential of sectorized networks, such as the rate gain achieved when multiple sectors can be simultaneously activated. In this paper, we focus on sectorized wireless networks, where sectorized infrastructure nodes with beam-steering capabilities form a multi-hop mesh network. We present a sectorized node model and characterize the capacity region of these sectorized networks. We define the flow extension ratio and the corresponding sectorization gain, which quantitatively measure the performance gain introduced by node sectorization as a function of the network flow. Our objective is to find the sectorization of each node that achieves the maximum flow extension ratio, and thus the sectorization gain. Towards this goal, we formulate the corresponding optimization problem and develop an efficient distributed algorithm that obtains the node sectorization under a given network flow with an approximation ratio of 2/3. Additionally, we emphasize the class of Even Homogeneous Sectorizations, which simultaneously enhances the efficiency of dynamic routing schemes with unknown arrival rates and increases network capacity. We further propose that if sectorization can be adapted dynamically over time, either a backpressure-driven or maximum weighted b-matching-based routing approach can be employed, thereby expanding the achievable capacity region while preserving stability under unknown traffic conditions. Through extensive simulations, we evaluate the sectorization gain and the performance of the proposed algorithms in various network scenarios.