ISSN : 1796-2021
Volume : 1    Issue : 2    Date : May 2006

Routing in Multi-Channel Wireless Ad-hoc Networks: OSPF-MCDS-MC
Unghee Lee, Scott F. Midkiff and Tao Lin
Page(s): 57-68
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The availability of low-cost network interface cards (NICs) has made the IEEE 802.11 medium
access control (MAC) protocol the de facto MAC standard for wireless mobile ad-hoc networks.
Although the IEEE 802.11 MAC protocol is designed to have stations share a single channel in a
network, many of the IEEE 802.11 physical (PHY) layer standards define multiple channels and
allow the simultaneous, non-interfering use of some of these channels. Therefore, simultaneous
communications can occur through different channels, offering the opportunity to increase effective
network capacity. We present an innovative routing protocol that utilizes multiple channels to
improve performance in a mobile ad hoc network. The key feature of the protocol is that nodes can
effectively use multiple channels for simultaneous useful transmissions, thus improving network
capacity. The proposed scheme requires minor changes to existing proactive or table-driven routing
protocols and no modifications to current the IEEE 802.11 MAC protocol. To mitigate the overhead of
periodic updates in proactive routing protocols, the proposed scheme divides the network layer into
control and data planes. To demonstrate the multi-channel routing scheme, we extend the
OSPFMCDS routing protocol to a multi-channel version, OSPFMCDS- MC or, more simply, OMM.
Simulation and experimental results indicate OMM successfully exploits multiple channels to
increase network capacity. The protocol allows the network goodput to increase in proportion to the
number of available channels, even as the number of nodes and network load increase, in both
single-hop and multiple-hop networks. We also present a prototype implementation for
experimental validation of the proposed multi-channel routing protocol scheme. The
implementation includes the multi-channel routing protocol and a virtual interface module, which
acts as a buffer for outgoing packets and performs channel-related functions, such as channel
selection and switching, while ensuring portability.

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