Abstract: A radio communications system (10) having a remote or mobile station (30) and at least two base stations (13, 14). ATM radio channels (31, 32) are provided between the remote station and base stations. The remote station (30) has a logic unit (520) for combining cell streams received from the first and second base stations during a handoff from the first base station to the second base station. A receiver in the remote station (30) is powered up during first time periods corresponding to physical layer synchronization cells arriving from one base station (13) and second time periods corresponding to ATM cells arriving from the other base station. When handoff conditions are met, the receiver is powered up for a third time period longer than the first and second time periods.

Abstract: A radio unit (12) for communication over a communication channel (300) having repeating frames. The radio unit has a memory (131) with a table (280) of time locations in a frame and indications of the availability of time locations for transmission. A time is selected from the table and a cell of data is transmitted on the channel at the selected time. If an acknowledgement to the cell is received at a receiver (102) the transmitter sends a series of further cells at corresponding times in later frames. Otherwise a different time is selected for a new access attempt. A sequence of ATM cells is prepared for transmission by forming data into cells each having synchronization information (230), a physical layer field (251), a sequence number (253) and an error check number (254). Error coding cells (245) are added, with error coding which is spread across the cells such that a lost cell is recoverable from adjacent cells.

Abstract: A wide bandwidth frequency discriminator circuit (200) employs a wide bandwidth limiting amplifier (202) to amplify the IF signal portion of a received RF signal. A frequency-to-voltage circuit 208 is provided having a bandwidth substantially greater than the bandwidth of the IF signal. This discriminator (200) operates to form a detection system capable of discriminating between desired and undesired components of the received RF signal even when said desired and undesired components are nearly identical in amplitude. This is due in part to the enhanced frequency response provided by the discriminator (200).

Abstract: A radio communications system (10) having a mobile station (30) and at least two base stations (13, 14). ATM radio channels (31, 32) are provided between the remote station and base stations. Each of the ATM channels supports communication though ATM cells over a common frequency band. At least one ATM node (21) is coupled to the base stations. A base station controller (11) is coupled to the ATM node. The base station controller has a combiner (303) for combining cell streams received from the first and second base stations and an ATM signalling circuit (330) for sending ATM commands to the ATM node for dividing cell streams at the ATM node to the first and second base stations. The remote station (30) has a logic unit (520) for combining cell streams received from the first and second base stations during a handoff from the first base station to the second base station.

Abstract: A target device (18) performs the steps of receiving a broadcast message via an out-of-band paging network (14) which message includes an identification of the sourcing device. The subscriber (18) automatically registers, responsive to the receipt of the broadcast message, with a local communication server (22) associated with an in-band communications network (12). The target subscriber (18) then uses the identification of the sourcing device (16) to respond to the communication from the sourcing device (16) to establish a communication path therewith through the local communication server (22). In a preferred embodiment, the target subscriber unit and method reside in an asynchronous transfer mode (ATM) network. In this manner, the present invention establishes a direct communication path between the local communications server (22) to which the target subscriber unit (18) is attached and the sourcing device (16) thereby minimizing network trafficking and inefficiency problems.

Abstract: A shared spectrum communications unit and system provides communications without interfering with incumbent point-to-point receivers. This system includes a transmitter (e.g., of a PCS device) and a geographical location device which is operatively associated with the transmitter. The geographical locating device determines the position of the transmitter, and provides position information to a frequency authorization device. Geographical information pertaining to the PCS device is compared with the locations of the incumbent point-to-point receivers, using a database of the frequency authorization device including the locations of the point-to-point receivers, and a frequency allocation/authorization is generated to the PCS device when the PCS device is located outside of a predetermined range associated with local point-to-point receivers. An authorized frequency is stored and employed by the frequency authorization device for control of the operating frequency of the PCS device.

Abstract: A frequency-locked loop (100) employs a controllable oscillator (102) for generating an output signal having a frequency, optional sampler (104), coupled to oscillator (102), for sampling the frequency of the output signal, a divider (106), coupled to optional sampling circuit (104), for dividing the output signal frequency to generate a prescaled signal and a microprocessor (108), coupled between the divider 106 and oscillator (102), for comparing the prescaled signal to a reference signal and generating a control signal for correcting frequency shifts based upon the comparison. The control signal generated by microprocessor (108) is non-continuous. During that time when microprocessor (108) generates no control signals, power is removed from various frequency-locked loop circuitry.

Abstract: An improved network interface architecture for a packet switch provides for the combination of both voice and data in a single switch using a common packet structure. It allows for the dynamic allocation of bandwidth based on system loading. This includes not only bandwidth within the voice or data areas of the frame, but also between the voice and data portions. The network interface (NI) provides a mechanism (the NI-Bus) of passing all packets through the Network Interface or allowing the packet devices to directly transfer packets between one another. The bandwidth allocation can easily be changed because the control and data memories are synchronized to one another. The network interface architecture, according to the invention, allows for the data packets and the control of bandwidth allocation to be controlled by a single switching device. It synchronizes the transfer of the data and the allocation of bus bandwidth.

Abstract: In a wireless TDMA network a control module (CM) sends a time stamp relative to the beginning of its frame in a synchronization packet allowing each of a plurality of user modules (UM) to maintain synchronization relative to the CM. The CM uses a plurality of directional antennas and transmits the synchronization packets over each antenna over a predetermined number of frames. The UMs use a receive time stamp to identify the beginning of a received synchronization packet. The difference between the time stamps combined with a delay constant is used by the UMs to adjust time synchronization to the CM frame.

Abstract: An improved network interface architecture for a packet switch provides for the combination of both voice and data in a single switch using a common packet structure. It allows for the dynamic allocation of bandwidth based on system loading. This includes not only bandwidth within the voice or data areas of the frame, but also between the voice and data portions. The network interface (NI) provides a method (the NI-Bus) or passing all packets through the Network Interface or allowing the packet devices to directly transfer packets between one another. The bandwidth allocation can easily be changed because the control and data memories are synchronized to one another. The network interface architecture, according to the invention, allows for the data packets and the control of bandwidth allocation to be controlled by a single switching device. It synchronizes the transfer of the data and the allocation of bus bandwidth.

Abstract: A common communication controller is linked to a plurality of peripheral devices by a network interface bus. Packets containing information is communicated between the controller and the peripherals over the bus which consists of a parallel packet bus and a plurality of control lines utilized to implement a communication protocol which increases the efficiencies of packet communications by the utilization of additional direct command lines between the communications controller and peripherals.

Abstract: A hierarchical addressing technique is employed in a packet communications system to enhance flexibility in storing and referencing packet information. This method permits packet message data and certain packet control data to be stored in memory locations without having to be duplicated at a different memory location prior to transmission of the packet. This method is preferably employed in a ring configuration in which a series of packets have addressing mechanisms which points sequentially to each other to form a ring of packets received or to be transmitted.

Abstract: An improved network interface architecture for a packet switch provides a mechanism for handling voice and data packets. Bandwidth allocation can be changed because control and data memories are synchronized to one another. A hierarchical addressing technique is employed to enhance flexibility in handling packet information. This method permits packet message data and certain packet control data to be stored in memory locations without having to be duplicated at a different memory location prior to transmission of the packet. In an exemplary wireless TDMA packet network a control module (CM) sends a time stamp relative to the beginning of its frame in a synchronization packet allowing each of a plurality of user modules (UM) to maintain synchronization relative to the CM. The CM uses a plurality of directional antennas and transmits the synchronization packets over each antenna over a predetermined number of frames.

Abstract: A communications system having a plurality of different radio-types (528, 530 and 532) when integrated into a single node or control module (500) provides communications with a plurality of different end users (502, 506 and 508) having different transmission protocols. The steps involved comprise coupling the plurality of communication devices (528, 530 and 532) together via a bus (526) and coupling at least one processing unit (517) to the bus (526). Signals received by RF devices (528, 530 and 532) are communicated onto the bus (526) and processed by the processing unit (517) into processed signals. Processed signals comprise data and control information which are stored in memory (522). Thereafter, the processed signals stored in memory (522) are returned back onto the bus (526) for use by at least one of the plurality of communication devices (528, 530 and 532).

Abstract: There is provided a mechanism for networking satellite and terrestrial networks. It comprises: maintaining subscriber-received power levels of terrestrial network transmissions about one order of magnitude above co-channel satellite transmissions to overcome interference and maintaining subscriber transmissions to terrestrial networks at power levels about one order of magnitude of the below co-channel transmissions to satellite networks to avoid causing interference at the satellite. Such power level maintenance is provided by the network in communication with such subscriber. Moreover, a non-orbiting ("grounded") satellite cooperates as a switching node of both the satellite network and a terrestrial network to relay information between a terrestrial subscriber and the satellite radiotelephone network over a terrestrial network. The terrestrial network and the satellite network may communicate via either the inter-satellite spectrum or the terrestrial-to-satellite spectrum.

Abstract: A wireless infrared (IR) communications system (100) for communicating packetized information (302) between a control module (12) and a plurality of UMs (14) via infrared transceivers (300/320) is described as having a selectable communications path. In this system at least the user module (14) has a plurality of IR device arrays (A1-A6) for receiving IR signals (312/312') in relatively narrow IR field of view sectors, and selection circuit (20), coupled to said plurality of IR device arrays (A1-A6), for selecting a communication path between the control module (12) and one of said plurality of IR device arrays (A1-A6), based at least partly on received signal (302') qualtity, so as to overcome reception errors caused by multipath interference.

Abstract: A wireless in-building RF communications system operates within a building in a microwave frequency range which is also utilized by a point-to-point microwave communication system such that frequency reuse is provided. Central modules and user modules each consist of RF transceivers and antenna systems. The wireless communication system includes a mechanism for limiting magnitude of RF signals transmitted by it from exceeding a predetermined level sufficiently small to prevent interference with the point-to-point communications system.

Abstract: There is provided a mechanism for networking satellite and terrestrial networks. It comprises: maintaining subscriber-received power levels of terrestrial network transmissions about one order of magnitude above co-channel satellite transmissions to overcome interference and maintaining subscriber transmissions to terrestrial networks at power levels about one order of magnitude of the below co-channel transmissions to satellite networks to avoid causing interference at the satellite. Such power level maintenance is provided by the network in communication with such subscriber. Moreover, a non-orbiting ("grounded") satellite cooperates as a switching node of both the satellite network and a terrestrial network to relay information between a terrestrial subscriber and the satellite radiotelephone network over a terrestrial network. The terrestrial network and the satellite network may communicate via either the inter-satellite spectrum or the terrestrial-to-satellite spectrum.

Abstract: An apparatus scales binary samples representing a predetermined waveform (109) to achieve every possible transition in a multi-level transmission system. The predetermined waveform (109) is partitioned into M symbol intervals, each symbol interval having a corresponding waveform represented by a series of binary samples V stored in M separate ROM devices (311-316). Depending on the required amplitude and polarity of the transition, logic blocks (351-356) control scaling multipliers (321-326) and polarity multipliers (331-336) to perform the required scaling and inverting of the binary samples retrieved from ROM (311-316). The scaled and inverted samples are added together by an adder (345) and sent to a D/A converter (350) where the desired scaled and inverted waveform is converted/generated from the scaled and inverted binary samples.

Abstract: A wireless RF communication system that shares frequency assignment with existing RF systems scans a set of possible operating frequencies for signals transmitted by the other systems. This data is sent to a frequency management center where a safe operating frequency is assigned. The new RF system periodically scans the set of frequencies and will automatically inhibit transmissions if a signal from another system is detected which exceeds a threshold, thereby indicating that a possibility exists for interference.