A new queueing model for QoS analysis of IEEE 802.11 DCF with finite buffer and load

Ren Ping Liu, Gordon J. Sutton, Iain B. Collings

Research output: Contribution to journalArticlepeer-review

87 Citations (Scopus)


Quality of Service (QoS) and queue management are important issues for IEEE 802.11 systems. However, existing 2-dimensional (2-D) Markov chain models of 802.11 systems are unable to capture the complete QoS performance and queueing behavior due to the lack of an adequate finite buffer model. We present a 3-dimensional (3-D) Markov chain that integrates the 802.11 system contention resolution and queueing processes into one model. The 3rd dimension, that models the queue length, allows us to accurately capture important QoS measures, delay and loss, plus throughput and queue length, for realistic 802.11 systems with finite buffer under finite load. We derive an efficient method for solving the steady state probabilities of the Markov chain. Our 3-D Markov chain is the first finite buffer model defined and solved for 802.11 systems. The solutions, validated by extensive simulations, capture the system dynamics over a wide range of traffic load, buffer capacity, and network size. Our 3-D model points to the existence of an effective maximum throughput and shows its relationship with buffer capacity. We demonstrate that our 3-D model can also be used in resource allocation to determine adequate buffer sizes under a particular QoS constraint.

Original languageEnglish
Article number5487530
Pages (from-to)2664-2675
Number of pages12
JournalIEEE Transactions on Wireless Communications
Issue number8
Publication statusPublished - Aug 2010
Externally publishedYes

Bibliographical note

An erratum for this article exists in IEEE Transactions on Wireless Communications, vol. 12, issue 10, p. 5374. DOI: 10.1109/TWC.2013.093013.131378


  • IEEE 802.11
  • multi-dimensional Markov chain
  • QoS
  • queueing analysis


Dive into the research topics of 'A new queueing model for QoS analysis of IEEE 802.11 DCF with finite buffer and load'. Together they form a unique fingerprint.

Cite this