Performance analysis of a multiple access protocol for voice and data support in multiuser broadband wireless LANs

Wireless Local Area Networks (WLANs) is one of the most promising access technologies for the upcoming fourth-generation wireless communication systems. In the last few years, several research efforts have been devoted to investigate possible multiple access schemes capable of supporting real-time traffic as well as best-effort data transmissions. In particular, the use of suitable transmission schemes allows not only to achieve higher data-rates, but also to perform resource allocation in order to guarantee specific service requirements. In this paper we propose a medium access control (MAC) scheme for a WLAN supporting real-time (voice) and best-effort (data) services, based on Orthogonal Frequency Division Multiplexing (OFDM) technique. A suitable analytical approach is proposed in order to derive the performance of the proposed MAC scheme. In particular, it is shown in the paper that a high overall network capacity in terms of simultaneously active users is achieved by effectively exploiting the multiuser capabilities offered by OFDM, together with a proper service differentiation. Work partially supported by MIUR within the WOMEN project. Romano Fantacci, (M’87,SM’91, F’05) born in Pistoia, Italy, graduated from the Engineering School of the Universit di Firenze, Florence, Italy, with a degree in electronics in 1982. He received his Ph.D. degree in telecommunications in 1987. After joining the Dipartimento di Elettronica e Telecomunicazioni as an assistant professor, he was appointed associate professor in 1991 and full professor in 1999. His current research interests are digital communications, computer communications, queuing theory, satellite communication systems, wireless broadband communication networks, ad-hoc and sensor networks. He has been involved in several European Space Agency (ESA) and INTELSAT advanced research projects. He is the author of numerous articles published in prestigious communication science journals. He guest edited special issues in IEEE Journals and magazines and served as symposium chair of several IEEE conferences, including VTC, ICC and Globecom. Professor Fantacci received the IEE IERE Benefactor premium in 1990 and IEEE COMSOC Award Distinguished Contributions to Satellite Communications in 2002. He is currently serving as Editor for Telecommunication Systems, IEEE Trans. Commun. and IEEE Transactions on Wireless Communications. Gianluca Vannuccini born in Florence, Italy, graduated in Electronics Engineering in 1999. He received his Ph.D. degree in Telematics and Information Society in 2003 from the Electronics and Telecommunications Department of the University of Florence. During 2002 he was for six months in IBM Zurich Research Laboratory, Zurich, Switzerland, working in a research project on IEEE 802.11e performance evaluation. During the Ph.D. course, he has published on several IEEE conferences and served as reviewer for several journals on the telecommunications and telematics research area. He has been IEEE student member since 1999 and IEEE member since 2004. He is now with the IT department of the Florence local government organization, where he works as a program manager on data quality and integration and e-government IT projects. Gabriele Vestri was born in Florence (Italy) in November 1976. He received his degree in telecommunications from the Universit di Firenze, Florence, Italy, in March 2002. He has been research scientist for CSO Ophthalmic (Florence) since September 2002. His current research interests include ophthalmic instruments, contact lens design, image processing, the effects of optical aberrations and of retinal architecture of the eye on visual performance.