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

The availability of low-cost network interface cards (NICs) has made the IEEE 802.11 medium access con- trol (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 simultane- ous, non-interfering use of some of these channels. There- fore, simultaneous communications can occur through dif- ferent channels, offering the opportunity to increase effec- tive network capacity. We present an innovative routing protocol that utilizes multiple channels to improve perform- ance 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 net- work capacity. The proposed scheme requires minor changes to existing proactive or table-driven routing proto- cols 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 OSPF- MCDS routing protocol to a multi-channel version, OSPF- MCDS-MC or, more simply, OMM. Simulation and experi- mental results indicate OMM successfully exploits multiple channels to increase network capacity. The protocol allows the network goodput to increase in proportion to the num- ber 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 rout- ing protocol scheme. The implementation includes the multi-channel routing protocol and a virtual interface mod-