| 摘要 |
<p>A half-duplex communication system is embodied in a push-to-talk cellular system such as a GPRS system. The system includes two or more terminals (1 A, 1 B, 1 C) one or more of which can operate in a hands-free mode. When in hands-free mode, a terminal (1 A) is offered the right-to-speak by a controller (11 A, 13 A, 15 A, 17 A) within the system without the need for a talk request from a user. This allows a hands-free user to participate safely in a communications session.</p> |
