Abstract: A point to multipoint channel extension protocol and system are disclosed. More particularly, the system includes an extension protocol for extending a point to point radio link between a primary station and a secondary station to a point to multipoint radio link in which the primary station broadcasts to the secondary stations. This is done by first informing the handset to which a point to point radio link has been set up that an extension is to be done so that the handset can switch off its transmitter, and then transmitting extension messages to all handsets. Furthermore, a transfer and skipping protocols are proposed with a reliable connection establishment by using a double checking protocol for seizing a pair of free channels.

Abstract: A free channel double checking protocol and system are disclosed. More particularly, the system includes at least one primary radio station and a plurality of secondary radio stations, in which a secondary radio station is matched to a primary radio station and a wireless communication is established via a full duplex communication link. The primary and the secondary stations establish the communication link using a free channel double checking protocol. The free channel doubles checking protocol checks whether a free channel exists between stations. After setting up the communication link, a calling station may confirm to a called station that a reliable communication link has been established.