Title :
A reservation random-access protocol for voice/data integrated spread-spectrum multiple-access systems
Author :
Tan, Lijun ; Zhang, Qi Tu
Author_Institution :
Dept. of Electr. Eng., Ryerson Polytech. Inst., Toronto, Ont., Canada
fDate :
12/1/1996 12:00:00 AM
Abstract :
Most code-division multiple-access (CDMA) systems described in the literature provide only one single service (voice or data) and employ the strategy of “one-code-for-one-terminal” for code-assignment. This assignment, though simple, fails to efficiently exploit the limited code resource encountered in practical situations. We present a new protocol called reservation-code multiple-access (RCMA), which allows all terminals to share a group of spreading codes on a contention basis and facilitates introducing voice/data integrated services into spread-spectrum systems. The RCMA protocol can be applied to short-range radio networks, and microcell mobile communications, and can be easily extended to wide area networks if the code-reuse technique is employed. In RCMA, a voice terminal can reserve a spreading code to transmit a multipacket talkspurt while a data terminal has to contend for a code for each packet transmission. The voice terminal will drop a long delayed packet while the data terminal just keeps it in the buffer. Therefore, two performance measures used to assess the proposed protocol are the voice packet dropping probability and the data packet average delay. Theoretical performance is derived by means of equilibrium point analysis (EPA) and is examined by extensive computer simulation
Keywords :
access protocols; cellular radio; data communication; delays; land mobile radio; multi-access systems; packet radio networks; probability; spread spectrum communication; voice communication; CDMA; RCMA protocol; code assignment; code division multiple access; code reuse technique; computer simulation; data packet average delay; data terminal; equilibrium point analysis; microcell mobile communications; multipacket talkspurt transmission; packet transmission; performance measures; reservation code multiple access; reservation random-access protocol; short-range radio networks; spread-spectrum multiple-access systems; spreading codes; system performance; voice packet dropping probability; voice terminal; voice/data integrated services; voice/data integrated systems; wide area networks; Delay; Intserv networks; Microcell networks; Mobile communication; Multiaccess communication; Performance analysis; Protocols; Radio network; Spread spectrum communication; Wide area networks;
Journal_Title :
Selected Areas in Communications, IEEE Journal on