Abstract: An apparatus and method of effecting hand-off of a mobile station in a first wireless communication system, which has a first mobile switching node operable with a first base station and a second mobile switching node operable with a second base station, and a second wireless communication system, is claimed. A handoff required message is received at the first mobile switching node, and sent to a second mobile switching node. A message from the second mobile switching node is sent to request allocation for a handoff. In an embodiment, this message is sent to the VLR of the second wireless communication system. In response, a handoff request acknowledge message is received by the second mobile switching node and sent to the first mobile switching node. An initial address message is sent to initiate a circuit connection between the first mobile switching node and the second mobile switching node. Then, the call is received from the first mobile switching node.

Abstract: A method for dialing a telephone number indirectly, including obtaining an alphanumeric identifier that is assigned to a telephone subscriber and associating the identifier with a destination telephone number of the telephone subscriber to form a mapping therebetween. The method further includes storing the mapping in a lookup table, dialing the identifier using an originating telephone, using the identifier as a pointer to the lookup table so as to recover the destination telephone number from the stored mapping, and establishing a connection between the originating telephone and a destination telephone via the destination telephone number.

Abstract: A CDMA mobile station (MS) can be engaged with a GSM subscriber identity module (SIM) to authenticate the MS with a GSM core infrastructure using a CDMA radio access network (RAN) through a hybrid CDMA/GSM message switching center (MSC), such that use of the CDMA RAN with the existing GSM core advantageously is facilitated.

Abstract: A method of effecting handoff of a mobile station from a first base station in a first cellular communications system controlled by a first mobile switching control station to a second base station in a second, different cellular system controlled by a second mobile switching control station is described. The method comprises measuring at the mobile station a parameter of a signal transmitted by said first base station and a parameter of a signal transmitted by said second base station. When the parameters reach a predetermined condition, a signal quality message is communicated from the mobile station via the first base station to said first mobile switching control station, which responds by generating information for a channel request message for the second mobile switching control station and transmitting the same to the mobile station.

Abstract: A method of effecting handoff of a mobile station from a first base station in a first cellular communications system controlled by a first mobile switching control station to a second base station in a second, different cellular system controlled by a second mobile switching control station is described. The method comprises generating at the second cellular communication system an authentication code as the result of applying an algorithm to a private key assigned to the mobile station for the second cellular communications system and a random number generated by the second cellular communications system. An authentication code is also generated at the first cellular communication system as the result of applying an algorithm to the private key and the random number. The authentication code generated at the first cellular communication system is then transmitted to a mobile station in a data packet, and, from there, the authentication code is transmitted to the second cellular communication system.

Abstract: A method for enabling a mobile telephone to operate in a communications network, including: generating a random authentication number and an expected response to the random authentication number, and transmitting a forward short message service (SMS) message incorporating the random authentication number to the mobile telephone. The method further includes generating at the mobile telephone, responsive to the random authentication number, an authentication response, and receiving from the mobile telephone a return SMS message incorporating the authentication response. The method also includes performing a comparison between the authentication response in the return SMS message and the expected response, and authenticating the mobile telephone to operate in the communications network responsive to the comparison.

Abstract: A method for simulating a communication system, including displaying a graphic representation of a state chart including a plurality of states and corresponding to a procedure followed by the communication system. The method also includes generating executable computer code responsive to the state chart, which code, when run by a simulator, causes the simulator to simulate the procedure. The method further includes incorporating into the computer code one or more pointers so as to generate, while the simulator is simulating the procedure, an indication in the graphic representation of the state in which the simulator is running.

Abstract: Apparatus for testing one or more mobiles, each mobile being adapted to transmit and receive respective signals compatible with a cellular communications network. The apparatus includes station simulation circuitry which is adapted to simulate a plurality of base station controllers (BSCs) operative simultaneously in the cellular communications network. The apparatus also includes mobile interface circuitry which is coupled to transfer the respective signals between the station simulation circuitry and the one or more mobiles.

Abstract: Testing apparatus, including a base station transceiver (BTS) simulator, which is adapted to simulate signals transmitted by a BTS and to process signals that are ordinarily received by the BTS. The apparatus also includes a channel simulation unit, which is adapted to provide a communication channel for the simulated signals and to communicate with a mobile cellular telephone, and a coupling connecting the BTS simulator and the channel simulation unit, enabling the BTS simulator and channel simulation unit to communicate digitally.

Abstract: A look-up table for use in a bridge employing negative filtering for interconnecting first and second networks in a data communications system. Associated with each data transmission is a source and destination address each having a total of (m+n) binary data bits, the bridge passing the data transmission from one network to the other unless the destination address is found in the look-up table and corresponds to the sending network. The look-up table comprises an encoding means responsive to an (m+n) bit address for producing first and second codes having respectively m and n bits of data which together allow the (m+n) bit address to be decoded unambiguously, a random access memory (RAM) coupled to the encoding means and having m addressable locations each for storing at least n bits of data, and a contents addressable memory (CAM) coupled to the encoding means and having a plurality of addressable locations each for storing at least (m+n) bits of data.