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Routing in Multi-Channel Wireless Ad-hoc Networks: OSPF-MCDS-MC

Unghee Lee1, Scott F. Midkiff1, and Tao Lin2
1. Bradley Department of Electrical and Computer Engineering Virginia Polytechnic Institute and State University Blacksburg, Virginia 24061 USA
2. PacketHop Networks Redwood, California 94065 USA

Abstract – The availability of low-cost network interfacecards (NICs) has made the IEEE 802.11 medium access control(MAC) protocol the de facto MAC standard for wirelessmobile ad-hoc networks. Although the IEEE 802.11 MACprotocol is designed to have stations share a single channelin a network, many of the IEEE 802.11 physical (PHY) layerstandards define multiple channels and allow the simultaneous,non-interfering use of some of these channels. Therefore,simultaneous communications can occur through differentchannels, offering the opportunity to increase effectivenetwork capacity. We present an innovative routingprotocol that utilizes multiple channels to improve performancein a mobile ad hoc network. The key feature of theprotocol is that nodes can effectively use multiple channelsfor simultaneous useful transmissions, thus improving networkcapacity. The proposed scheme requires minorchanges to existing proactive or table-driven routing protocolsand no modifications to current the IEEE 802.11 MACprotocol. To mitigate the overhead of periodic updates inproactive routing protocols, the proposed scheme divides thenetwork layer into control and data planes. To demonstratethe multi-channel routing scheme, we extend the OSPFMCDSrouting protocol to a multi-channel version, OSPFMCDS-MC or, more simply, OMM. Simulation and experimentalresults indicate OMM successfully exploits multiplechannels to increase network capacity. The protocol allowsthe network goodput to increase in proportion to the numberof available channels, even as the number of nodes andnetwork load increase, in both single-hop and multiple-hopnetworks. We also present a prototype implementation forexperimental validation of the proposed multi-channel routingprotocol scheme. The implementation includes themulti-channel routing protocol and a virtual interface module,which acts as a buffer for outgoing packets and performschannel-related functions, such as channel selectionand switching, while ensuring portability.

Index Terms - wireless ad hoc networks, mobile ad hoc networks,multi-channel routing, ad hoc routing protocols

Cite: Unghee Lee, Scott F. Midkiff, and Tao Lin, "Routing in Multi-Channel Wireless Ad-hoc Networks: OSPF-MCDS-MC," Journal of Communications, vol. 1, no. 2, pp. 57-68, 2006.