QoS mechanisms for multimedia communications over TDMA/TDD WLANs

The design of high-performance wireless LAN technologies making use of TDMA/TDD MAC is a very active area of research and development. The control of the network resources of such networks is taken care by a central controller. The mobile terminals may place their resource requests by making use of a well-defined set of primitives. In turn, the central controller allocates the channel bandwidth among all the competing mobiles. In this work, we undertake the design and performance evaluation of a set of QoS-aware mechanisms built on top of the underlying signalling and bandwidth allocation mechanisms provided by most wireless LANs standards. On our design, we assess the amount of overhead introduced by the proposed mechanisms: an important feature when designing scalable mechanisms for wireless environments. Furthermore, we validate the effectiveness of our proposed schemes by quantitatively evaluating the video quality as perceived by the end user. Our results show that the proposed schemes are able to guarantee the QoS requirements of the various services: voice, video, best-effort, and background. 2006 Elsevier B.V. All rights reserved.