Voice over WLAN (VoWLAN) - A wireless voice alternative?

Voice over WLAN (VoWLAN) is a natural evolution of VoIP. It is also a potential supplement or a potential competitor to 3G mobile systems. This article presents an overview of WLAN technologies and the issues that are relevant for voice communication over WLAN. The basic IEEE 802.11 mechanisms, and new security and QoS mechanisms recently being standardised by IEEE are described. Handover issues are addressed. A review of available papers on real-time communication over WLAN highlights the challenges to VoWLAN. There is also a short discussion on 3G-VoWLAN interworking. Finally user equipment aspects and the market potentials are discussed. Introduction Wireless Local Area Networks (WLANs) have become very popular in recent years. The most popular technology is based on IEEE Standard 802.11 [1]. 802.11-based WLANs are often considered as wireless extension to Ethernet standardised in IEEE Standard 802.3 [2]. WLAN is both used as an alternative and a complement to wired LAN. With the increasing popularity of IP technology, real-time applications such as interactive two-way voice and multimedia over IP have become popular. A natural evolution of voice over IP is voice over WLAN (VoWLAN). Like VoIP the growth of the VoWLAN market has been slower than analysts predicted a 1-2 years ago. Still it is predicted that the market will take off soon. The main hurdles to VoWLAN seems to be,

[1]  William A. Arbaugh,et al.  An empirical analysis of the IEEE 802.11 MAC layer handoff process , 2003, CCRV.

[2]  Adam Wolisz,et al.  Voice transmission in an IEEE 802.11 WLAN based access network , 2001, WOWMOM '01.

[3]  Sachin Garg,et al.  Can I add a VoIP call? , 2003, IEEE International Conference on Communications, 2003. ICC '03..

[4]  Ramón Agüero,et al.  Behavior of UDP-based applications over IEEE 802.11 wireless networks , 2001, 12th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications. PIMRC 2001. Proceedings (Cat. No.01TH8598).

[5]  Danilo Bruschi,et al.  Voice over IPsec: analysis and solutions , 2002, 18th Annual Computer Security Applications Conference, 2002. Proceedings..

[6]  David R. Bull,et al.  An evaluation of the performance of IEEE 802.11a and 802.11g wireless local area networks in a corporate office environment , 2003, IEEE International Conference on Communications, 2003. ICC '03..

[7]  Pierre R. Chevillat,et al.  The role of radio LANs in the wireless evolution , 2002, The 13th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications.

[8]  MishraArunesh,et al.  An empirical analysis of the IEEE 802.11 MAC layer handoff process , 2003 .

[9]  Etsi Secretariat,et al.  Digital cellular telecommunications system (Phase 2+); Enhanced Full Rate (EFR) speech transcoding , 1998 .

[10]  Rastin Pries,et al.  Performance Comparison of Handover Mechanisms in Wireless LAN Networks , 2004 .

[12]  A. Girotra,et al.  Performance Analysis of the IEEE 802 . 11 Distributed Coordination Function , 2005 .

[13]  Prathima Agrawal,et al.  Voice performance in WLAN networks - an experimental study , 2003, GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489).

[14]  Marceau Coupechoux,et al.  Voice over IEEE 802.11b Capacity , 2004 .