| 摘要 |
In a secure trunking communication system, limited secure service is provided during periods of limited service or failsoft operations using the following method. When the limited service or failsoft condition is detected, a limited secure service message or a failsoft service message, respectively, is transmitted to those system components utilizing encryption keys, including console interface units (CIU) (106-107) and communication units (111-113). Upon reception of the limited secure service message, the communication units load at least one limited service key. Simultaneously, the console interface units also load the at least one limited service key. Upon reception of the failsoft service message, the console interface units load at least one failsoft key. Simultaneously, the communication units also load the at least one failsoft key. The communication units and the CIUs use the limited service keys or the failsoft keys until normal operation is restored. |
