Overview
Introduction
Even a casual observer of the current trend in computing devices today sees an increasing tendency towards more mobile and compact computing devices, even in not so obvious places such as the family car. The starting premise of this proposal is that future wireless communication environments will be characterized by deeply networked physical spaces. The assumption is that users want access anywhere, anytime from anything that communicates.
The objective of this project was to develop a new media access protocol that can sustain the future communication needs in multihop multimedia wireless networks. The novelties of the project are: (i) a graceful rate adjustment algorithm that achieves fair channel access and a low collision rate, (ii) control theoretical analysis of the algorithm’s parameters setting, and (iii) provision of QoS support to diverse multimedia traffic. In addition, the proposed protocol adheres to the IEEE 802.11 CSMC/CA standard [1]. The adherence to open standards broadens the scope of usage of our algorithm, making it interoperable with other third party network interface cards that adhere to these open standards. The adoption of such a technique provides significant power savings, high channel efficiency, as well as quality of service support. None of the earlier solutions provide such characteristics.
The following challenges were dealt with in the project:
1. Multimedia traffic: With the introduction of the next generation wireless 4G systems, multimedia applications that include data, video and voice, will be the dominant applications. The delivery of multimedia information significantly increases the amount of traffic transmitted over the wireless channels as well as introduces the need to provide quality of service (QoS) support to the diverse media streams.
2. Quality of Service: each traffic class requires different quality of service support in terms of bandwidth and delay. The MAC protocol needs to differentiate between the different traffic streams and provide each one with the required QoS.
3. Limited available power: mobility which is the main advantage of using wireless communication imposes limitations on the amount of available battery power. This limitation imposes restrictions in the design of MAC protocols, i.e., we need to minimize the amount of processing and communication at each node.
5. Multihop topology: The multihop structure of the high speed wireless networks is necessary due to the larger geographical span of such networks and the lack of wired infrastructure connections at all times, i.e., the lack of the ability to reach the wired infrastructure within one hop. The fact that we have a multihop wireless environment [2] with no central coordinator, suggests that we have to use random access based MAC protocols.
6. Adherence to legacy standards: Innovative mechanisms for delivery must not make fundamental differences to already existent infrastructure for delivery. An incremental approach would be more practical and easily accepted.
This research work is supported by grants from:
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| National Science Foundation | Army Research Office | Microsoft Corporation |