The Circuit Reservation Multiple Access (CRMA) protocol is a new protocol for wireless indoor communications. It integrates voice and data traffic on a Time Division Duplexed channel. As with Mthe well known Packet Reservation Multiple Access (PRMA) protocol, CRMA is a hybrid TDMA/Slotted ALOHA protocol. Speech packets follow a TDMA scheme and data packets are transmitted with Slotted ALOHA. For speech traffic, speech activity detection is used to enhance the system performances. To avoid collisions between speech and data packets, the stations transmitting data sense the channel before a transmission. The protocol is designed to guarantee high quality speech transmission: the voice traffic does not suffer any delay and has a higher priority than data traffic. Nevertheless, data traffic has relatively high throughputs and low packet delays. An analytical model of the protocol is presented. The system performances are analysed and the results are compared with those of a PRMA system.