Skip to the main content

Original scientific paper

https://doi.org/10.24138/jcomss.v2i4.277

VoIP Call Admission Control in WLANs in Presence of Elastic Traffic

Boris Bellalta ; Departament de Tecnologia, Universitat Pompeu Fabra, Barcelona, Spain
Michela Meo ; Dipartimento di Elettronica, Politecnico di Torino, Italy
Miquel Oliver ; Departament de Tecnologia, Universitat Pompeu Fabra, Barcelona, Spain


Full text: english pdf 1.527 Kb

page 322-330

downloads: 373

cite


Abstract

VoIP service over WLAN networks is a promising alternative to provide mobile voice communications. However, several performance problems appear due to i) heavy protocol overheads, ii) unfairness and asymmetry between the uplink and downlink flows, and iii) the coexistence with other traffic flows. This paper addresses the performance of VoIP communications with simultaneous presence of bidirectional TCP traffic, and shows how the presence of elastic flows drastically reduces the capacity of the system. To solve this limitation a simple solution is proposed using an adaptive Admission and Rate Control algorithm which tunes the BEB (Binary Exponential Backoff) parameters. Analytical results are obtained by using an IEEE 802.11e user centric queuing model based on a bulk service M=G[1;B]=1=K queue, which is able to capture the main dynamics of the EDCA-based traffic differentiation parameters (AIFS, BEB and TXOP). The results show that the improvement achieved by our scheme on the overall VoIP performance is significant.

Keywords

Hrčak ID:

180871

URI

https://hrcak.srce.hr/180871

Publication date:

22.12.2006.

Visits: 756 *