Title of article :
Dynamic adaptation policies to improve quality of service of real-time multimedia applications in IEEE 802.11e WLAN Networks
Author/Authors :
Ramos، Naomi نويسنده , , Panigrahi، Debashis نويسنده , , Dey، Sujit نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2007
Pages :
-510
From page :
511
To page :
0
Abstract :
With the increased popularity of wireless broadband networks and the growing demand for multimedia applications, such as streaming video and teleconferencing, there is a need to support diverse multimedia services over the wireless medium. In order to efficiently address these diverse needs, efforts have been pursued to provide Quality of Service (QoS) mechanisms for medium access, resulting in a standard called IEEE 802.11e. One of the enhancements proposed in IEEE 802.11e is a polling-based access mechanism, which is targeted for real-time multimedia flows. In this polling-based scheme, scheduling and time allocation are based on flow reservations. Hence, the effectiveness of the mechanism is heavily dependent on the accuracy of the flow requirements in the reservation. Flow requirements, however, can vary over time and an allocation based on fixed reservations cannot address this variability. This limitation, which is present in the reference scheduler of IEEE 802.11e, leads to degraded multimedia quality for flows with variable requirements, even when channel resources are available. In order to address the above limitation, we present an adaptation framework that dynamically adjusts the polling-based access mechanism and associates flows to different modes of access (polling-based/contention-based), according to the current needs of the application, as opposed to solely relying on the reservation parameters. We demonstrate that with our adaptation, the achieved QoS for real-time multimedia streams, in terms of delay and throughput metrics, can be significantly improved compared to other known mechanisms. Additionally, we show the benefits of our adaptation framework on overall multimedia quality and system capacity.
Keywords :
Quality of service , IEEE 802.11e , Service level agreements , Wireless LAN , Video streaming
Journal title :
Wireless Networks
Serial Year :
2007
Journal title :
Wireless Networks
Record number :
20638
Link To Document :
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