A near-optimum MAC protocol based on the distributed queueing random access protocol (DQRAP) for a CDMA mobile communication system

• Published in: IEEE journal on selected areas in communications Vol. 18; no. 9; pp. 1701 - 1718
• Main Authors: Alonso, L., Agusti, R., Sallent, O.
• Format: Journal Article Publication
• Language: English
• Published: New York IEEE 01.09.2000; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Access control; Access protocols; Code division multiple access; Communication system control; Delay; Delays; Enginyeria de la telecomunicació; Land mobile radio; Media Access Protocol; Mobile communication; Multiaccess communication; Preserves; Protocol; Queueing theory; Queues; Radio receivers; Random access; Road accidents; Robustness; Studies; Switches; Telecommunication; Telecommunication traffic; Telecomunicació; Traffic engineering; Traffic flow; Àrees temàtiques de la UPC
• ISSN: 0733-8716; 1558-0008
• DOI: 10.1109/49.872957

This paper presents and analyzes a new near-optimum medium access control (MAC) protocol. The proposed access scheme is suitable for a CDMA mobile communication environment, and keeps under control and upper bounded the number of simultaneous transmissions. It has a delay performance approaching that of an ideal optimum M/M/K system, where K is the number of spreading codes being used (maximum number of simultaneous transmissions). The protocol is a free random access protocol when the traffic load is light, and switches smoothly and automatically to a reservation protocol when traffic load becomes heavier. It is based on distributed queues and a collision resolution algorithm. Moreover, a physical receiver structure is proposed and analyzed in order to preserve the robustness of the protocol in a wireless link. The results obtained show that the protocol outperforms other well known medium access protocols in terms of stability and delay, even when taking into account the loss caused by channel propagation conditions.