Idle-signal casting multiple access with collision detection (ICMA-CD) for land mobile radio

Abstract

A population of mobile terminals communicating with a central station over a packet-switched multiple-access radio channel is investigated. In land mobile radio communication, in which terminals cannot sense the carrier transmitted from other terminals (either because they are out-of-range or obstructed), a central controlled multiple access system in which a central station broadcasts idle/busy information of the access channel is used for multiplexing the packets from the terminals. Idle-signal casting multiple access (ICMA), which is a practical application of this central controlled system, has been used in the Nippon Telegraph and Telephone Public Corp. (NTT) mobile phone system for some years. ICMA-CD, which is an advanced ICMA scheme characterized by collision detection and evaluates its improved throughput, channel capacity and loss probability in a mobile radio fading environment with restrictions on retransmission, is proposed. It is clarified that ICMA-CD is suitable for the mobile multiple access scheme, especially in the case where packet detection delay and collision recovery time are short and offered traffic is heavy.