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 multiple-user subscriber unit (MCU) (110) is used by subscribers (240) in a group of subscribers to obtain communications services from the communication system. MCU (110) is co-located with a mobile vehicle and a group of subscribers. The MCU (110) and procedure (300) enable the MCU to reduce impulsive loading of the communication system caused by simultaneously requests for service. MCU (110) determines a set of tasks which includes a number of call-processing tasks, a number of hand-off tasks, and a number of re-registration tasks. Priorities are established for the tasks which must be performed. A schedule is established based on the priorities and the amount of time required to perform the tasks and the total amount of time available to perform the tasks. Tasks are performed according to the schedule and this reduces impulsive loading of the communication system (100).

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 communication system (100) includes satellites (102,104) and a mobile exchange unit (MXU) (120) for exchanging communication information with users. A satellite (102) generates synchronous timing frames requiring users operating through an MXU (120) to anticipate timing and frequency requirements to participate in communications. An MXU (120) must advance transmissions to a satellite (102) to insure transmissions arrive at satellite (102) within the proper synchronous receive window. Such advanced transmissions by MXU (120) interfere with reception of a ring alert/page transmission (130) which contains the location of broadcast channels (86) designating an incoming call or page data transmissions. The MXU (120) alternatively extracts a broadcast channel location from a candidate hand-off list being transmitted by a satellite (102) to in-use transceivers (310). The MXU 120 then distributes the location of the broadcast channel to those transceivers (310) presently not in-use.

Abstract: A communication system includes base communication units (105, 155) facilitating a communication link with portable communication units (110) in motion relative to base communication units. The relative motion between base communication units (105, 155) and portable communication units (110) introduces Doppler frequencies into communication links (115, 165). When portable communication units (110) travel in a predictable direction (119), frequency offsets for Doppler compensation are generally predictable. However, when portable communication units (110) move erratically in relationship to a base communication unit (105, 155), frequency offsets for Doppler compensation are not easily calculated. Incorporation of velocity vector data into the frequency offset calculation for Doppler compensation provides reliable tracking and Doppler frequency compensation for erratic motion of portable communication units (110).