Abstract: Systems and methods are described for efficiently transmitting packetized data from a sender to a receiver over a communications link. A compression context is established between the sender and the receiver based upon commonalities in each of the data packets prior to transmitting the data over the communications link. The data is compressed according to the compression context to thereby create compressed data packets, and the compressed data packets are transmitted to the receiver across the communications link. By establishing compression contexts prior to transmission, the need for in-band signaling is reduced or eliminated.

Abstract: A user equipment (UE) device and associated operating techniques can be utilized to manage the queuing of network service requests in a distributed manner throughout a data communication system. The request queuing methodology leverages request queues maintained at UE devices within the system. An embodiment of a UE device that supports such request queuing includes a processor and a request queue coupled to the processor. The request queue is configured to queue one or more requests for network resources as instructed by the processor, resulting in one or more held requests. The UE device also includes a receiver element coupled to the processor. The receiver element is configured to receive a notification from the network communication component, where, in response to receiving the notification, the processor prepares the one or more held requests for transmission to the network communication component at different times.

Abstract: Systems and methods are described for efficiently transmitting packetized data from a sender to a receiver over a communications link. A compression context is established between the sender and the receiver based upon commonalities in each of the data packets prior to transmitting the data over the communications link. The data is compressed according to the compression context to thereby create compressed data packets, and the compressed data packets are transmitted to the receiver across the communications link. By establishing compression contexts prior to transmission, the need for in-band signaling is reduced or eliminated.

Abstract: A method for masking a location (142) of a mobile subscriber in a cellular communications network is disclosed. The subscriber location (142) is masked by dividing a territory of cellular coverage into a grid (100) of cells (102-118) and dislocating the actual location (142) to a center of a cell (124) or to a point within a circle (140).

Abstract: A group radio communication system (20) includes a group controller (24) which communicates through a satellite-based packet switched data communication network (22) to converters (28). The converters (28) are located within radio coverage areas (36) of various radio sub-networks (26). Each radio sub-network (26) includes a base station (32), controller (30) and any number of subscriber radios. The controllers (30) manage point-to-multipoint communications between subscriber radios (34) within their radio sub-networks (26), and the group controller (24) manages point-to-multipoint communications between radio sub-networks (26). The converters (28) translate between protocols (38, 38′) established for communications within specific radio sub-networks (26) and a protocol (56) established for communication over the packet switched data communication network (22). The group controller (24) duplicates and distributes packets (118) originating in one radio sub-network (26) to other radio sub-networks (26).

Abstract: A point-to-multipoint (PTM) communication system (20) includes a cellular radio infrastructure (22) having base stations (32) implemented in satellites (34) placed in low earth orbits (38). PTM subscriber radios (24) share common cellular radio infrastructure (22) multipoint channels (52) to engage in a common PTM communication session while the cellular radio infrastructure (22) also conveys point-to-point communications. A group control computer (28) constructs a channel list (126) which is downloaded to PTM subscriber radios (24). The channel list (126) identifies multipoint channels (52) and indicates when and where the channels (52) are active. Without emitting transmissions to the cellular radio infrastructure (22), PTM subscriber radios (24) autonomously switch to new multipoint channels (52) in response to their current time and location and the channel list (126).

Abstract: An interworking unit (14) for providing an interface between a digital communication network (12) and a public switched telephone network (PSTN) (16) includes a de-vocoder (30), a protocol termination unit (32), and a signal combiner (34) for processing signals being transferred from the digital network (12) to the PSTN (16). A digital communication signal received by the interworking unit (14) from the digital network (12) is processed by both the de-vocoder (30) and the protocol termination unit (32). The outputs of the de-vocoder (30) and the protocol termination unit (32) are then combined into a uniquely formatted signal that is then delivered into the PSTN (12). Similar functionality is also provided for processing signals in the reverse direction. The interworking unit 14 is capable of processing signals traversing the interface between the networks (12, 16) without a priori knowledge of the signal type being processed.

Abstract: A communication system (10) includes a group call controller (GCC) (26) for use in establishing, maintaining, and controlling the provision of group call services within the communication system (10). To initiate a group call session for a particular subscriber group, a group call request is delivered to the GCC (26) that identifies the desired group. Upon receipt of the request, the GCC (26) coordinates the delivery of group call notification to the members of the identified group to notify the members of the initiation of the group call session and to identify to the members a physical communication channel (36) to be used by each member to participate in the group call. Upon receipt of the notification, the group members each tune to a corresponding physical communication channel (36) and are immediately made part of the group call. The group members are not required to make any transmissions on the physical channel (36) to participate in the group call.

Abstract: A method for masking a location (142) of a mobile subscriber in a cellular communications network is disclosed. The subscriber location (142) is masked by dividing a territory of cellular coverage into a grid (100) of cells (102-118) and dislocating the actual location (142) to a center of a cell (124) or to a point within a circle (140).

Abstract: A point-to-multipoint (PTM) radio communication system (20`) includes a cellular radio infrastructure (22) having base stations (32) implemented in satellites (34) placed in low earth orbits (38). PTM subscriber radios (24) share common cellular radio infrastructure (22) multipoint channels (52) to engage in a common PTM communication session while the cellular radio infrastructure (22) also conveys point-to-point communications. The shared multipoint channels (52) are operated in according with different protocols to deliver system information to PTM subscriber radios (24), to provide access to PTM subscriber radios (24), to provide synchronization, to originate a PTM monolog and to be one of many targets of a PTM monolog.

Abstract: A system for encrypting and verifying a data packet includes an encryptor (20), a decryptor (30), an error detector (40), and switch (65). A data packet with embedded error detection codes is encrypted by the encryptor (20), decrypted by the decryptor (30), and then the error detector (40) examines the embedded error detection codes to determine if the data packet has had errors introduced during the encryption/decryption process. When errors are detected, the switch (65) is opened to keep erroneous data from being transmitted.

Abstract: A method and apparatus for providing location-based intercept in a system includes an intercept monitoring unit (210) for dynamically modifying an intercept target list (245) in a communications switch (240). The intercept monitoring unit (210) determines, as a function of user location, whether the user's call should be intercepted. If so, either an updated entry is made to the intercept target list (245), or an entire updated copy of the intercept target list (237) is downloaded to the communications switch (240).

Abstract: A method for providing location based intercept in a satellite communications system (10) includes the steps of determining a location area of a party (220), determining whether the location area is one to be monitored (240), and conditionally routing the call to an intercept gateway (250). An intercept gateway (32) is a gateway that intercepts all or part of the calls received, and can also function as a home gateway (30) or a visiting gateway (40).

Abstract: A system and method provides signaling privacy for communications between nodes of a communications network (30). Multiple logical links exist between distinct network nodes (38-40, 42, 50-53) of the communication network (30). Signaling privacy is achieved by a subscriber unit (80) providing encryption/decryption of signaling data messages at the messaging level. The subscriber unit (80) employs a signaling encryptor/decryptor (86) along the signaling path, which enables the signaling data messages to be separately encrypted from data on the traffic channel. The encrypted signaling data can then be sent along a different logical link from the traffic, while maintaining cipher key synchronization between the signaling encryptor/decryptor (86) and a network encryptor/decryptor (78) at a remote end of the logical link which transports the encrypted signaling data.

Abstract: A group radio system (10) uses a group radio controller (230) to connect and manage remote units (20-100) through a wireline switched telephony network. The group radio controller receives voice or data from any of the remote units and repeats this to the others who are connected to the group channel. The group radio controller also assigns remote units in communication with the group channel via satellites (300,400) and other remote units also in communication with the group channel via a terrestrial cellular host network (90) to be anchor radios. The use of anchor radios for these types of users significantly lowers the cost to the group for this type of global radio service.

Abstract: In a global satellite communication system (10) that provides antenna beams that move with respect to Earth's surface, gateways (22) send ring alerts directed to subscriber units (26) based on a list of antenna beams. The list of antenna beams is determined by a dot product between a subscriber unit's basis vector and antenna beam vectors. Ring alerts are transmitted in antenna beams when the dot product exceeds a predetermined threshold. Subscriber units listen for ring alerts in the same antenna beams of the list by calculating the list the same way the gateway calculates the list.

Abstract: A method for assigning a system location to an ISU (32) residing in a wireless communication system coverage area (20) that has a plurality of billing territories (40). Base points (42) are defined to be proximate the billing territories (40) such that each of the base points (42) provides a system location for a corresponding billing territory (40). Each of the billing territories (40) has a plurality of reference points (44) distributed therein in accordance with a geographic independent algorithm such that each of the reference points (44) is described by an offset from the corresponding base point (42) of the corresponding billing territory (40). By obtaining an actual location (54) of the ISU (32) and identifying one of the reference points (44) closest to the actual location (54), the ISU (32) is assigned the system location of the identified reference point (44). In a preferred embodiment, the method and apparatus of the present invention are used in a mobile satellite system (19).

Abstract: In satellite based communication systems (30), real time monitoring of communication links (23-25) and the subsequent adaptations to overcome problems with certain links (23,25) provides the communication system (30) with the ability to adapt to changing conditions. A satellite-based communication system (30) can be adapted to provide an improved method for establishing communication links (23,25) between ground stations (14) and space-based satellite switches (11). Common earth-based termination nodes are replaced by intelligent switches (14). Alternate links are established using links (20,21) between intelligent space-based switches (11), links (24) between intelligent earth-based switches (14), and links (23,25) between intelligent space-based switches (11) and intelligent earth-based switches (14). The controller (54) in the intelligent earth-based switch (14) allows the system to automatically adapt to failure, overload, and other conditions.

Abstract: A radio telecommunication network (10) includes satellites (12) which project cells (30) on the surface of the earth. Mobile units (16) are alerted to incoming calls when they receive ring signals. Ring signal coverage parameter values are selected in response to differentiating data (46) which cause different ring signals to be activated for mobile units (16) which appear to be proximately located. An illumination area ring signal coverage parameter may have a value selected in response to differentiating data (46) so that larger illumination areas are used for higher speed mobile units (16"). A transmission power ring signal coverage parameter may have a value selected in response to differentiating data (46) so that higher power ring signals are used in specific situations identified by the differentiating data (46).

Abstract: An interworking unit (14) for providing an interface between a digital communication network (12) and a public switched telephone network (PSTN) (16) includes a de-vocoder (30), a protocol termination unit (32), and a signal combiner (34) for processing signals being transferred from the digital network (12) to the PSTN (16). A digital communication signal received by the interworking unit (14) from the digital network (12) is processed by both the de-vocoder (30) and the protocol termination unit (32). The outputs of the de-vocoder (30) and the protocol termination unit (32) are then combined into a uniquely formatted signal that is then delivered into the PSTN (12). Similar functionality is also provided for processing signals in the reverse direction. The interworking unit 14 is capable of processing signals traversing the interface between the networks (12, 16) without a priori knowledge of the signal type being processed.