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: 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 used by a communication system (100) to register communication system users which use service provider equipment. Multiple-user and special purpose single-user communication units (110) are provided and/or operated by service providers. MCUs (110) can be located on mobile vehicles or in fixed locations. The system along with MCUs (110) collect registration information and usage information for individual users (440) and individual MCUs (110). Service providers receive billing information concerning the usage of their MCUs (110) by communication system users. After communication system (100) registers each user whose registration information is contained within the at least one combined request message, communication system (100) provides communication services to each user and billing information services to the service provider for the communications service and the service provider furnishing the communications equipment.

Abstract: A communication system including a constellation of satellites and a multi-channel unit having a plurality of co-located transceivers operative for exchanging communication information with users, and for monitoring a plurality of spot beams transmitted from one or more of the satellites for ring alert data contained within broadcast channels, and for monitoring and prioritizing the strongest of "n" broadcast channels for ring alerts based upon signal strength, upon a continuous sampling of ring alert channels contained within one or more broadcast channels, upon broadcast signal strength in relation to idle transceiver availability and the communication system geometries, and upon the monitoring of broadcast channels contained within candidate handoff lists contained within one or more of the traffic channels of in-use transceivers, for the purpose of increasing the probability of receiving a ring alert.

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: 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 multiple subscriber unit (MSU) (600) is co-located with a mobile vehicle (110) and is coupled to multiple communication units (620) which can be used by MSU users to establish communication links between the MSU users and other terminals. The MSU (600) and a method for operating the MSU perform selective registration (200-210, 300-322) for the MSU users. In order to reduce unnecessary registration traffic, only after the MSU determines (202, 303) that a particular MSU user desires to receive incoming calls will the MSU register (208, 320) the particular MSU user with a communication system. If an MSU user does not desire to receive incoming calls, the MSU will not register (204, 304) the MSU user with the communication system.

Abstract: A plurality of subscriber units (16) operate in a communication system (10) having dynamic nodes such as satellites (12). A communication management center (14) controls interface parameters and protocol employed by subscriber units (16). A system and method is employed to dynamically alter interface protocol used by subscriber units (16). Communication management center (14) calculates a balance between a first portion of subscriber units (16) assigned to perform attach-detach registration and a second portion of subscriber units (16) assigned to abstain from performing attach-detach registration when associating and disassociation from communication system (10). As available communication bandwidth varies according to present of future communication patterns, subscriber units (16) may be dynamically reassigned perform or abstain from performing attach-detach registration.

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.