Optimal Rate Sampling in 802.11 systems
2014 (English)In: Proceedings - IEEE INFOCOM, 2014, 2760-2767 p.Conference paper (Refereed)
Rate Adaptation (RA) is a fundamental mechanism in 802.11 systems. It allows transmitters to adapt the coding and modulation scheme as well as the MIMO transmission mode to the radio channel conditions, and in turn, to learn and track the (mode, rate) pair providing the highest throughput. So far, the design of RA mechanisms has been mainly driven by heuristics. In contrast, in this paper, we rigorously formulate such design as an online stochastic optimisation problem. We solve this problem and present ORS (Optimal Rate Sampling), a family of (mode, rate) pair adaptation algorithms that provably learn as fast as it is possible the best pair for transmission. We study the performance of ORS algorithms in stationary radio environments where the successful packet transmission probabilities at the various (mode, rate) pairs do not vary over time, and in non-stationary environments where these probabilities evolve. We show that under ORS algorithms, the throughput loss due to the need to explore sub-optimal (mode, rate) pairs does not depend on the number of available pairs. This is a crucial advantage as evolving 802.11 standards offer an increasingly large number of (mode, rate) pairs. We illustrate the efficiency of ORS algorithms (compared to the state-of-the-art algorithms) using simulations and traces extracted from 802.11 test-beds.
Place, publisher, year, edition, pages
2014. 2760-2767 p.
Algorithms, Fading channels, MIMO systems, Stochastic systems, Adaptation algorithms, Fundamental mechanisms, MIMO transmission, Modulation schemes, Non-stationary environment, Packet transmissions, State-of-the-art algorithms, Stochastic optimisation, Optimization
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-168364DOI: 10.1109/INFOCOM.2014.6848225ISI: 000361544200308ScopusID: 2-s2.0-84904438136ISBN: 9781479933600OAI: oai:DiVA.org:kth-168364DiVA: diva2:816109
33rd IEEE Conference on Computer Communications, IEEE INFOCOM 2014; Toronto, ON; Canada; 27 April 2014 through 2 May 2014
QC 201506022015-06-022015-06-022015-10-29Bibliographically approved