Abstract: A system (20) transmits a digital data stream (22) using a lossy compression service (24) having a communication path (28) through which compressed signals propagate. The system includes a data conditioner (36) configured to condition the received digital data stream (22) to produce data subsets (66). A frame generator (36) expands each of the data subsets (66) to generate distinct signal sets (68). The distinct signal sets (68) are expressed in a data size greater than the data subsets (66) to compensate for lossy compression cause by the lossy compression service (24). A transmitter is in communication with the frame generator (36) and transmits digitized ones of the distinct signal sets (68) in frames of a digital bit stream (126) over the communication path (28).

Abstract: Apparatus and a method are described for providing a security token. The security token may be used for numerous applications, but is particularly useful in conjunction with radiotelephone devices having secure functions. In accordance with the invention the user must insert a PIN and utter sounds. The radiotelephone device will activate the secure functions only if the PIN is correct and the sounds uttered are authenticated against voice feature vectors stores it the token.

Abstract: Apparatus and a method are described for providing for multiple secure functions in a host or wireless radiotelephone. Access to the functionality of the radiotelephone is provided by means of a smart card or security token features contained therein. The determination of the secure function which is accessed is determined by encrypted credential information carried in the smart card. The smart card may be used for numerous applications, but is particularly useful in conjunction with radiotelephone devices having a plurality of secure communication levels. The radiotelephone device will activate the secure levels based on the security level algorithm carried in the smart card.

Abstract: A secure communications system (501) including a local digital terminal (510) coupled to an interworking function (538). The interworking function (538) couples the digital radio network (121) to a PSTN (542, 546, 548) and a remote analog communication terminal (552). The system (501) includes a novel method of establishing an end-to-end communication channel between local digital (510) and remote analog (552) terminals wherein the local digital terminal establishes (510) a direct digital channel (121) between itself (510) and the interworking function (538) and transmits a message describing its signaling capabilities to the interworking function (538). The interworking function (538) then trains its modem with the modem of the remote analog terminal (552) such that signaling capabilities of the local digital terminal (510) and the remote analog terminal (552) are not violated.