An adaptive access control scheme for a reservation TDMA/adaptive modulation system

In realizing multimedia communication systems in land mobile communications, high‐frequency efficiency must be achieved, while satisfying various requirements for transmission quality depending on the media. In the proposed system, voice and the data of long message size are transmitted by the reservation TDMA (time division multiple access) system, and data of shorter message size are transmitted by the slotted ALOHA system, using slots which are not used for voice or long data. In order to ensure a larger number of idle slots for short data transmission, the voice activation technique and adaptive modulation are utilized in voice transmission. This paper considers the reservation TDMA/adaptive modulation system, and the transmission of voice/data integrated traffic at high speed and high efficiency through the common radio channel. An adaptive access control system is proposed in which the threshold for separating long and short data is automatically controlled according to traffic variation. It is verified by a simulation that the proposed system is effective in integrating data with high efficiency and in reducing delay in data transmission, while maintaining the voice transmission capacity. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 85(11): 77–86, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.1140