Abstract: Application service is provided for a subscriber unit (SU), employing a first protocol, in a communication network employing a second protocol. The method includes receiving a CAI OTAR message from the SU. The CAI OTAR message includes at least a key management message (KMM) and a CAI header of the SU. The method then includes determining that the first protocol employed by the SU is different from the second protocol associated with the communication network based on the received CAI OTAR message. The method further includes creating a key management message (KMM) preamble, associated with the second protocol, based on at least one of the CAI header and configuration information of the SU, and creating a data link independent (DLI) OTAR message associated with the second protocol. The DLI OTAR message includes the received KMM.

Abstract: The application discloses a method and apparatus for providing interoperability for a mobile subscriber unit (MSU), employing a first protocol e.g., SCEP, with a packet-data subsystem operating at a second protocol e.g., SNDCP. The method includes determining that the first protocol employed by the MSU is different from the second protocol operated by the packet data subsystem. The method then includes creating a context information for the MSU when the determined first protocol is different from the second protocol. Further, the method includes determining a header associated with the second protocol based on the created context information and then receiving at least one data packet associated with the first protocol from the MSU. The method then encapsulates the at least one data packet with the determined header associated with the second protocol. The method then transmits the at least one encapsulated data packet to the communication network through a context manager.

Abstract: Application service is provided for a subscriber unit (SU), employing a first protocol, in a communication network employing a second protocol. The method includes receiving a CAI OTAR message from the SU. The CAI OTAR message includes at least a key management message (KMM) and a CAI header of the SU. The method then includes determining that the first protocol employed by the SU is different from the second protocol associated with the communication network based on the received CAI OTAR message. The method further includes creating a key management message (KMM) preamble, associated with the second protocol, based on at least one of the CAI header and configuration information of the SU, and creating a data link independent (DLI) OTAR message associated with the second protocol. The DLI OTAR message includes the received KMM.

Abstract: The application discloses a method and apparatus for providing interoperability for a mobile subscriber unit (MSU), employing a first protocol e.g., SCEP, with a packet-data subsystem operating at a second protocol e.g., SNDCP. The method includes determining that the first protocol employed by the MSU is different from the second protocol operated by the packet data subsystem. The method then includes creating a context information for the MSU when the determined first protocol is different from the second protocol. Further, the method includes determining a header associated with the second protocol based on the created context information and then receiving at least one data packet associated with the first protocol from the MSU. The method then encapsulates the at least one data packet with the determined header associated with the second protocol. The method then transmits the at least one encapsulated data packet to the communication network through a context manager.

Abstract: When a roaming communication unit (15) requires an updated encryption key to ensure continued secure communications with other communication units of its home system, it transmits a rekey request to a base site (16) for the system (14) in which it has a presence. The latter provides the rekey request to a key management facility (17) for that system. This key management facility, in turn, provides the rekey request to the key management facility (13) for the roaming communication unit's home system (10). The latter then forwards a rekeying message that includes a rekeying encryption key to the roaming communication unit (15) with the second system's key management facility (17) acting as an intermediary. In a preferred embodiment, the rekey message is encrypted using an encryption key that is presently available to the roaming communication unit but not to the second system's key management facility.