A MULTI-SLOT ACCESS PROTOCOL FOR TDMA-TDD PACKET RADIO CHANNEL - APPLICATION TO PHS PACKET DATA SYSTEM

This paper proposes a new MAC protocol and physical channel control sc hemes for TDMA-TDD multi-slot packet channel. The goal of this study i s to support both circuit-switched and packet-switched communications on the same resources and to enable highspeed packet transmission usin g a multi-slot packet channel. In the proposed channel central schemes , three points are taken into account; 1) effective sharing of time sl ots and frequencies with minimum impact on circuit communications, 2) compatibility with the existing access protocol and equipment, and 3) dynamic allocation of uplink and downlink slots. As for the MAC protoc ol, we adopt BRS (Block Reservation Scheme) and adaptive access contro l scheme to the proposed MAC protocol. In addition, to overcome the in herent disadvantage of TDD channels, packet scheduling and access rand omizing control are newly proposed in this paper. The results of throu ghput and delay evaluations confirm that downlink capacity can be dras tically enhanced by the dynamic allocation of uplink and downlink slot s while corruption under heavy traffic loads is prevented by applying the adaptive traffic load control scheme.