Separation of Routing and Scheduling in Backpressure-Based Wireless Networks

TL;DR

This paper introduces Diff-Max, a novel approach that separates routing and scheduling in backpressure-based wireless networks, enhancing throughput, practicality, and modularity, supported by simulations.

Contribution

It presents a new framework that decouples routing and scheduling in backpressure networks, simplifying implementation and improving performance.

Findings

Significant throughput improvement with Diff-Max

Easier practical implementation due to layer separation

Modular design allowing independent operation of routing and scheduling

Abstract

Backpressure routing and scheduling, with its throughput-optimal operation guarantee, is a promising technique to improve throughput in wireless multi-hop networks. Although backpressure is conceptually viewed as layered, the decisions of routing and scheduling are made jointly, which imposes several challenges in practice. In this work, we present Diff-Max, an approach that separates routing and scheduling and has three strengths: (i) Diff-Max improves throughput significantly, (ii) the separation of routing and scheduling makes practical implementation easier by minimizing cross-layer operations; i.e., routing is implemented in the network layer and scheduling is implemented in the link layer, and (iii) the separation of routing and scheduling leads to modularity; i.e., routing and scheduling are independent modules in Diff-Max, and one can continue to operate even if the other does not. Our approach is grounded in a network utility maximization (NUM) formulation and its solution. Based on the structure of Diff-Max, we propose two practical schemes: Diff-subMax and wDiff-subMax. We demonstrate the benefits of our schemes through simulation in ns-2.