Performance Evaluation of Cooperative Forwarding Schemes in Wireless Networks with General Topology and Multiple Traffic Flows: an Optimization Approach

Antonio Capone(caponeelet.polimi.it)
Stefano Gualandi(gualandielet.polimi.it)
Di Yuan(diyuaitn.liu.se)

Abstract: Cooperation schemes are the key elements of infrastructure-less wireless networks that allow nodes that cannot directly communicate to exchange information through the help of intermediate nodes that relay their messages towards destination. The most widely adopted approach is based on hop-by-hop forwarding at network layer along a path to destination. Cooperative relaying brings cooperation al physical layer in order to fully exploit wireless resources. The concept exploits channel diversity by using multiple radio units to transmit the same message. The underlying fundamentals of cooperative relaying have been quite well-studied from a transmission efficiency point of view, in particular with a single source and destination. Results of its performance gain in a multi-hop networking context with multiple sources and destinations are, however, less available. In this paper, we provide an optimization approach to assess the performance gain of cooperative relaying vis-a-vis conventional multi-hop forwarding for joint packet routing and transmission scheduling under general network topology. The approach extends and generalizes classical optimization schemes for non-cooperative networks. We provide numerical results demonstrating that the gain of cooperative relaying decreases when network connectivity and the number of traffic flows increase due to the effect of interference and resource reuse limitation. In addition to quantifying the performance gain, our approach leads to a new framework for optimizing routing and scheduling in cooperative networks.

Keywords: cooperative relaying, ad hoc networks, multi-hop forwarding, routing, scheduling, column generation

Category 1: Applications -- OR and Management Sciences (Telecommunications )

Category 2: Combinatorial Optimization

Category 3: Network Optimization

Citation: Politecnico di Milano, Dipartimento di Elettronica e Informazione, June 2009.

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Entry Submitted: 09/06/2009
Entry Accepted: 09/06/2009
Entry Last Modified: 09/06/2009

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