Abstract: A switch system (20) switches at least sixty-four asynchronous transfer mode (ATM) input data streams (22) into at least sixty-four ATM output data streams (24). The switch system (20) includes a backplane assembly (38) having integral data transmission lines, integral clock transmission lines, and discrete slots (36). A single stage space switch circuit card (26), a clock circuit card (28), and input circuit cards (30) are connected to separate slots (36) in the backplane assembly (38). The integral data transmission lines are coupled between the input circuit cards (30) and the switch circuit card (26) and the integral clock transmission lines are coupled between the clock circuit card (28) and the input circuit cards (30). Data path lengths for the integral data transmission lines differ in the backplane assembly (38), and clock path lengths for the clock transmission lines differ in the backplane assembly.

Abstract: A high speed packet switch (100) is provided which uses a fabric size of 128.times.128 and operates at a 2.5 Gbps rate. Parallel data transport techniques are used to obtain the 2.5 Gbps data rate while operating internal switches (160) at slower rates. The packet switch fabric is fabricated on a single ASIC using high speed CMOS.

Abstract: A packet data communication system (10) where multiple users (87) can access the same channel (22) to maximize an efficiency of the communication system (10). Each channel (22) is divided into time slots. Each time slot is allocated to a user based on the user's request (303) for time slots and the availability of time slots. If time slots are available, then the system (10) will inform the user (87) and allocate the time slot to the user (87, 305). If there are no available time slots, then the system (10) will inform the user (87) that no time slots are available and access to the system's channel is denied. The user (87) will continue to request access (303) to the system (10) as long as the user has data packets to send.

Abstract: A satellite-based cellular communication system (100) is used to provide emergency services to subscriber units located anywhere on the earth. The surface of the earth is divided into defined areas and emergency codes are assigned to each one of the defined areas. As subscriber units (150) move relative to the surface of the earth, the satellite-based cellular communication system (100) updates the emergency codes stored in the subscriber units (150) as required based on the subscriber unit's current location. The subscriber unit (150) uses the stored emergency codes to determine when a user is requesting emergency services and prioritizes the call accordingly.

Abstract: Originating and terminating units (32, 36) communicate through a network (22) containing satellites (46, 50, 52) and gateways (44, 48). The network (22) receives user-prioritized lists (62) of protocols from the respective units (32, 36). The network (22) compares the lists (62) to determine the highest-priority common protocol. If a common protocol exists, the network (22) establishes a link between the units (32, 36) utilizing the common protocol and excluding the gateways (44, 48). If a common protocol does not exist, the network (22) selects as originating and terminating protocols the highest-priority protocols in the respective lists (62). If the originating protocol consumes a greater number of resources, the network (22) establishes the link, translating between protocols in an originating gateway (44) and excluding a terminating gateway (48). Otherwise, the network (22) establishes the link, translating in the terminating gateway (48) and excluding the originating gateway (44).

Abstract: A system facilitates global cellular communication by utilizing a gateway satellite (1000) which communicates with low-earth orbiting satellites (10, 20) via signalling links (1001, 1002). Switching is performed in each of the satellites (10, 20) and switching interconnections as well as voice path communications are switched via the gateway satellite (1000). With switching performed in a gateway satellite (1000), the use of a ground-based gateway network (74) is minimized and, in some cases, eliminated.

Abstract: A method and apparatus for a communication system (100) to register groups of co-located users in a mobile vehicle (110) involves collecting (200) registration information for multiple users by a Vehicle Communications Control Unit (500) (VCCU) on board the mobile vehicle (110), creating (202) at least one group registration request message by the VCCU (500), and sending the at least one group registration request message to an Earth Terminal (102) (ET) of the communication system (100). After the communication system (100) registers each user whose registration information is contained within the at least one group registration request message, the ET (102) sends (312) at least one group registration response message to the VCCU (500), where the message includes information describing whether each registration attempt was successful. The VCCU (500) can then inform (210) each user as to the status of the registration attempt.

Abstract: Methods (100, 150, 200) and systems (10, 30, 41) are used to expedite access for a period of time for those subscriber units (30) which have previously executed the complete visited gateway access procedures. By checking certain information sent by a subscriber unit (30) upon initialization and determining whether the information falls within a predetermined period of time, the visited gateway (41) enables itself to receive calls directly from the subscriber unit (30) and informs the subscriber unit (30) that it (30) can send calls directly to the visited gateway (41). The subscriber unit (30) thereafter sends calls to the visited gateway (41) instead of to the home gateway (40) until it (30) is no longer allowed to do so.

Abstract: A method and apparatus for handing off communications between a primary satellite system (500) and an alternate satellite system (550) determines (602) when a hand-off condition for the primary satellite system (500) exists. An alternate satellite (552) is determined (604, 904) which has a coverage area (554) which is positioned such that the alternate satellite (552) can provide an alternate communication link (556). A hand-off between the primary satellite system (500) and the alternate satellite system (550) is then performed (606). When the hand-off condition is alleviated (610), a hand-off back to the primary satellite system (550) is performed and normal operations are resumed (600).

Abstract: A digital cellular telecommunication network (30) uses transcoders (50) which vocode voice using a maximal lossy compression algorithm which conserves spectrum usage. A call path for an intercepted call is looped from an outer space satellite (32) network into an intercepting terrestrial gateway (34). Compressed call data for each of two half-calls in this call path bypass normal transcoders (50) through the use of rate adapters (80) which translate between data communication protocols that operate at different data rates without voice coding and decoding. After rate adaptation, the compressed call data are combined in a conference bridge (90), and routed to a monitoring center (60). A subscriber unit (36), a second device (48), and the monitoring center (60) all receive call data which has experienced only one compression/decompression cycle.

Abstract: A method (100) and system (10) are used to expedite access for a period of time for those subscriber units (30) which have previously executed the complete home gateway access procedures. By checking certain information sent by a subscriber unit (30) upon initialization and determining whether the information falls within a predetermined period of time, a home gateway (40) directly notifies a visited gateway (41) to handle the call setup and bypasses the need to reexecute the full access procedures at the home gateway (40).

Abstract: Methods (100) assign a subscriber unit (30) to be served by a gateway (40) based on such factors as the location of the subscriber unit (30), whether the call is to be intercepted and whether the serving gateway (40) is capable of servicing the connection request. The method (100) does not drop a call because the visited gateway initially assigned by the home gateway (40) is unable to service the connection request; but instead routes the call around disabled or congested gateways to an alternate visited gateway that is capable of servicing the connection request.

Abstract: A digital telecommunication network (10) provides an audio processor (56) for each call in each external node (14). The audio processor (56) includes a vocoder and additional functions. At a source external node (14), the audio processor (56) detects DTMF events and encodes the events in a call-related signalling packet (26) which conveys a history of all DTMF activity at the source node over the past several seconds. In addition, the source node detects silence and configures a call-related signalling packet (26) to instruct a destination node (14) how to synthesize comfort noise. Speech is encoded as vocoded voice packets rather than call-related signalling packets. At a destination external node, the node's audio processor (56) distinguishes call-related signalling from vocoded voice. The audio processor (56) synthesizes voice, comfort noise, DTMF signals, and other signals in response to the call-related signalling packets and vocoded voice packets.

Abstract: A subscriber unit (26) contains location data that expires after predetermined time periods that are based on the subscriber's mobility. When the location data has not expired, the subscriber unit requests access (108) to a satellite communication system (10) by providing location data within an access request message. The communication system performs a quick check (214) to validate the location data. Accordingly, time-consuming geo-location procedures are avoided when a call is initiated or being received. When the location data has expired, the subscriber unit requests access (110) without providing location data within the access request message. The communication system performs a complete geolocation procedure (210) to determine valid location data for the subscriber unit. The location data is sent (211) to the subscriber unit and time stamped (113).

Abstract: A digital cellular telecommunication network (30) uses transcoders (50) which vocode voice using a maximal lossy compression algorithm which conserves spectrum usage. A call path for an intercepted call is looped from an outer space satellite (32) network into a terrestrial gateway (34). Compressed call data for each of two half-calls in this call path are duplicated at any of the network nodes and inserted into the opposing half-call. In addition, the compressed call data are decompressed in a gateway transcoder (50), combined in a conference bridge (90), and routed to a monitoring center (60). A subscriber unit (36), a second device (48), and the monitoring center (60) all receive call data which has experienced only one compression/decompression cycle.

Abstract: In a communication system (10) which includes a communication unit (56) (CU), a Mobile-Switch Interface (50) (MSI), and a Mobile services Switching Center (40) (MSC), a method for location registration and call continuation involves the MSI (50) determining (174) whether the CU (56) intends to utilize a system service after the CU (56) completes a location updating process without releasing a channel between the CU (56) and the MSC (40). When the CU (56) does intend to utilize the system service directly after the location updating process, the MSI (50) allows the CU (56) to utilize the system service regardless of whether the MSC (40) indicated that the CU (56) cannot utilize the system service without first releasing the channel.