Paper Info
Title
Feedback-Based Control for Providing Real-Time Services With the 802.11e MAC
Abstract
The 802.11e working group has recently proposed the hybrid coordination function (HCF) to provide service differentiation for supporting real-time transmissions over 802.11 WLANs. The HCF is made of a contention-based channel access, known as enhanced distributed coordination access, and of a HCF controlled channel access (HCCA), which requires a Hybrid Coordinator for bandwidth allocation to nodes hosting applications with QoS requirements. The 802.11e proposal includes a simple scheduler providing a Constant Bit Rate service, which is not well suited for bursty media flows. This paper proposes two feedback-based bandwidth allocation algorithms to be used within the HCCA, which have been referred to as feedback based dynamic scheduler (FBDS) and proportional-integral (PI)-FBDS. These algorithms have been designed with the objective of providing services with bounded delays. Given that the 802.11e standard allows queue lengths to be fed back, a control theoretic approach has been employed to design the FBDS, which exploits a simple proportional controller, and the PI-FBDS, which implements a proportional-integral controller. Proposed algorithms can be easily implemented since their computational complexities scale linearly with the number of traffic streams. Moreover, a call admission control scheme has been proposed as an extension of the one described in the 802.11e draft. Performance of the proposed algorithms have been theoretically analyzed and computer simulations, using the ns-2 simulator, have been carried out to compare their behaviors in realistic scenarios where video, voice, and FTP flows, coexist at various network loads. Simulation results have shown that, unlike the simple scheduler of the 802.11e draft, both FBDS and PI-FBDS are able to provide services with real-time constraints. However, while the FBDS admits a smaller quota of traffic streams than the simple scheduler, PI-FBDS allows the same quota of traffic that would be admitted using the simpl- - e scheduler, but still providing delay bound guarantees
Year
DOI
Venue
2007
10.1109/TNET.2007.892881
Networking, IEEE/ACM Transactions
Keywords
Field
DocType
PI control,access protocols,bandwidth allocation,computational complexity,delays,feedback,quality of service,telecommunication congestion control,telecommunication traffic,wireless LAN,802.11 WLAN,802.11e MAC,HCF controlled channel access,QoS requirements,bounded delays,bursty media flows,call admission control scheme,computational complexity,constant bit rate service,contention-based channel access,enhanced distributed coordination access,feedback based dynamic scheduler,feedback-based bandwidth allocation algorithm,feedback-based control,hybrid coordination function,ns-2 simulator,proportional-integral controller,proportional-integral-FBDS,real-time services,traffic streams,QoS,Real-time applications,wireless networks
Wireless network,Control theory,IEEE 802.11e-2005,Bandwidth allocation,Call Admission Control,Computer science,Computer network,Quality of service,Communication channel,Constant bitrate,Distributed computing
Journal
Volume
Issue
ISSN
15
2
1063-6692
Citations 
PageRank 
References 
64
3.43
19
Authors
4
Name
Order
Citations
PageRank
G. Boggia122317.74
Pietro Camarda282251.74
Luigi Alfredo Grieco31852104.72
Saverio Mascolo41468108.28