| One feature that distinguishes the ad hoc wireless network from traditional wired networks and PCS (personal communication network) is that all hosts in an ad hoc wireless network are allowed to move freely without the need for static access points. This distinct feature, however, presents a great challenge to the design of the routing scheme and the support of multimedia services, since the link quality and the network topology may be fast changing as hosts roam around.; In this dissertation, we investigate the behaviors of existing routing algorithms. None of them satisfies the stringent requirements of ad hoc wireless networks. These requirements include: high accuracy, low overhead, scalability in a large network, the possibility of providing QoS routing, etc. Therefore, we propose a new routing approach for ad hoc wireless network: Global State Routing (GSR). Similar to link state routing, GSR maintains a global view of network topology. But unlike link state routing, GSR uses the fisheye technique to keep the control message small, thus reducing the consumption of bandwidth by control overhead. As a result, GSR can be scaled for use in networks with large populations. GSR can also be extended with QoS parameters to perform QoS routing for multimedia applications.; In order to validate the results in our investigation, all schemes are simulated and/or implemented in our testbed at UCLA. The implementation of our testbed also involves the creation of several new features in the operating system to provides QoS support in wireless networks, and the creation of new applications which fully utilize this QoS information. With the integration of these features across various layers, we can realize a truly mobile, multimedia, multihop wireless network. |
