METHOD TO DETERMINE TG AND ENCRYPTION KEY FOR USE IN A SUBSCRIBER TO LAND INTERCONNECT CALL
Original Publication Date: 1996-May-01
Included in the Prior Art Database: 2002-Apr-12
The system is a Project 25 conventional land mobile radio system using conventional talk groups (TG). Subscriber to Land Interconnect calls are ini- tiated by the subscriber and are routed through a digital interface unit (DIU) and a mobile radio tele- phone interface (MRTI). Security is provided by the DIU. The interconnect call starts with the subscriber sending an interconnect access message. The DIU/MRTI will respond to this with a dial tone. Then the subscriber sends dialing digits and the DIU/MRTI responds with a ring tone and the phone call is connected with voice communications to follow.