DocumentCode :
3123528
Title :
Joint Scheduling of Rate-guaranteed and Best-effort Services over a Wireless Channel
Author :
Zafer, Murtaza ; Modiano, Eytan
Author_Institution :
Laboratory for Information and Decision Systems, Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, USA. murtaza@mit.edu
fYear :
2005
fDate :
12-15 Dec. 2005
Firstpage :
6022
Lastpage :
6027
Abstract :
We address multi-user scheduling over the down-link channel in wireless data systems. Specifically, we consider a time-slotted system with a single transmitter serving multiple users. With fixed power transmission, the channel condition of a user determines the reliable rate of communication to that user in a particular time-slot. The user set consists of, (i) throughput guaranteed (QoS) users, and, (ii) best effort (BE) users. For such a system we obtain the optimal policy that serves the QoS users with minimum time-slot utilization, thereby, maximizing the remaining fraction of time-slots allocated to the BE users. We present a simple geometric visualization of the optimal policy. In the special scenario of symmetric Rayleigh fading, we obtain explicit formulas that relate the achievable throughput rate guarantee to the number of QoS users supportable and the fraction of time-slots allocated to the BE users. Finally, we compare the throughput results for the optimal policy with the random-scheduling policy and show that gains on the order of ln(N) can be achieved by exploiting multi-user diversity, where N is the number of QoS users.
Keywords :
Downlink; Multi-user diversity; Opportunistic scheduling; Quality of Service; Wireless fading channel; Base stations; Data systems; Delay; Downlink; Mobile handsets; Quality of service; Rayleigh channels; Space technology; Throughput; Time varying systems; Downlink; Multi-user diversity; Opportunistic scheduling; Quality of Service; Wireless fading channel;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Decision and Control, 2005 and 2005 European Control Conference. CDC-ECC '05. 44th IEEE Conference on
Print_ISBN :
0-7803-9567-0
Type :
conf
DOI :
10.1109/CDC.2005.1583125
Filename :
1583125
Link To Document :
بازگشت