In this thesis we propose a multi-channel wireless network based on nodes that use multiple 802.11 radio interfaces. The proposed system is singular, as it does not require new hardware or a new MAC, but insteadleverages commodity 802.11-based products. With this system, we target scenarios where the nodes are stationary and where their location can often be controlled. We evaluate the performance in this setup using an ad-hoc network approach whereby nodes generate as well as forward data. We also present and appraise apurely-wireless multi-channel infrastructure, whichoperates like the WLAN infrastructure-based networks in existence today, but without any fixed-line support. In such an infrastructure nodes dedicated for routing purposesprovide wireless connectivity to users.We show that a multi-interface system provide significantly higher capacity in many scenarios. Our work puts forward various challenges, points to various anomalies in the operation of the 802.11 MAC protocol, and shows the need to tackle unfairness issues.Our experiments demonstrate that the mere use of more dual-interface nodes does not necessarilycreate higher capacity. We also show that traffic differentiation significantly increases aggregatethroughput in realistic scenarios. Finally, we provide an example of how simple channel-allocationalgorithms in controlled random topologies can allow us to take advantage of a multi-interface system.
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