METHOD TO DETERMINE TG ENCRYPTION KEY IN VLR WHEN HLR IS NOT AVAILABLE
Original Publication Date: 1997-Sep-01
Included in the Prior Art Database: 2002-May-30
The system is a secure multikey 2-way radio trunked OminiLink system. An OminiLink system consists of many zones and each zone has a Zone Controller (ZC). A talkgroup (TG) is assigned to a zone which is then called its controlling zone (CZ). The CZ has the HLR for the TG which contains the encryption key number for the console to use with that secure TG. Other zones that are involved with the call are called participating zones (PZ). The key number information at a PZ is stored in a VLR.