| 摘要 |
A TETRA gateway apparatus 1 can send and receive call traffic and SDS messages via radio signals with the fixed radio infrastructure 4 on the one hand, and can send and receive call traffic and SDS messages via radio signals with one or more direct mode operating terminals 2 and 3, etc., on the other hand. The gateway apparatus 1 is also configured to be operable such that when it provides a gateway function to direct mode operating terminals, such as a TETRA terminal 2, it can also allow a user 9 of the gateway apparatus 1 to participate in a call or SDS session that is proceeding via the gateway apparatus 1. A TETRA direct mode repeater apparatus can be similarly configured. |
