Implementation of Distributed Time Exchange Based Cooperative Forwarding

TL;DR

This paper presents a distributed implementation of time exchange-based cooperative forwarding in wireless networks, significantly improving network goodput through a novel algorithm tested on USRP hardware.

Contribution

It introduces a polynomial time distributed solution for joint time slot exchange and relay selection, optimizing network goodput in a practical testbed.

Findings

TE significantly increases network goodput

Distributed algorithm achieves near-optimal performance

Proportional fair goodput optimization demonstrated

Abstract

In this paper, we design and implement time exchange (TE) based cooperative forwarding where nodes use transmission time slots as incentives for relaying. We focus on distributed joint time slot exchange and relay selection in the sum goodput maximization of the overall network. We formulate the design objective as a mixed integer nonlinear programming (MINLP) problem and provide a polynomial time distributed solution of the MINLP. We implement the designed algorithm in the software defined radio enabled USRP nodes of the ORBIT indoor wireless testbed. The ORBIT grid is used as a global control plane for exchange of control information between the USRP nodes. Experimental results suggest that TE can significantly increase the sum goodput of the network. We also demonstrate the performance of a goodput optimization algorithm that is proportionally fair.