Abstract: The addition and removal of a dither signal takes place by generation of a first signal (102) and a second signal (104) by a first signal source (151) and a second signal source (152). A dither generator (103) is provided that generates a dither signal (106) that is added to the first signal (102) and subtracted from the second signal (104). The first signal (102) with dither added, and the second signal (104) with dither subtracted enter respective Digital to Analog Converters (DACs) (109, 111) and are converted to analog signal equivalents. Finally, the respective analog signal equivalents are summed together to form a composite signal with the dither signal (106) substantially eliminated.

Abstract: In a communication system where frame boundaries for the discrete frames for different users may be offset relative to one another, assignment of a remote unit (125) to a particular frame offset occurs by a processor (321) determining a frame offset belonging to a group that is the least busy group of all possible groups. In addition, during handoff of the remote unit (125) from a serving base station (130) to a neighboring base station, the remote unit (125) is attempted to be kept within the same call group, however should the same call group of the neighboring base station be filled, the remote unit (125) is placed in a second call group that is one call group prior to the current call group.

Abstract: A method and system for facilitating a handoff of a remote mobile unit in a communication system 12 having a plurality of base stations (16 and 22), employs base stations (16 and 22) along a coverage area seam (10) that have a soft handoff subsystem (24) collocated with conventional base station circuitry (44) to facilitate soft handoff. The soft handoff subsystem (24) includes a transceiver (36) for generating and receiving a first group of dedicated soft handoff channels that are an orthogonally related subset of a separate second group of spread spectrum coded traffic channels wherein the soft handoff subsystem is under control of the source base station controller (14). The dedicated soft handoff channels are assigned to a specified source base station (16). Preferably the soft handoff subsystem (24) generates only the first group of dedicated soft handoff channels without pilot channels or synchronization channels.

Abstract: Data transmission within a broad-band communication system occurs as follows: During time periods where a remote unit (113) is not actively communicating to a base station (100) utilizing either a fundamental or a supplemental channel, the remote unit (113) is actively or periodically monitoring a forward control channel (IS-95A paging channel) for notification of any pending transmission by the base station (100). The base station (100) determines that a high data rate transmission to the remote unit (113) needs to take place and determines if supplemental channel circuitry (105) is available for utilization. Shortly prior to supplemental channel availability, the base station (100) notifies the remote unit (113) of a pending data transmission and assigns the remote unit (113) a fundamental channel to establish an appropriate transmit power level. Finally, data transmission to the remote unit (113) takes place utilizing the supplemental channel.

Abstract: Power control in a spread-spectrum communication system takes place by receiving a signal from a remote unit (713) at both a first (701) and a second (707) base station and combining the two received signals to form a single combined signal. The power of the remote unit (713) is adjusted based on the single combined signal.

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 processing system that is accessible via a number of speech transmission media. Access to the processing system may be made via a mobile radiotelephone, land line telephone, acoustic link or datalink. Access to programs, files and data is based upon the security of the communication media and authentication of the user.

Abstract: Signals comprising time of transmission indications relative to a common time base (302) are transmitted by at least two fixed transceivers (110-116). When the signals are received by a mobile unit (160), a time of reception indication relative to the common time base is calculated for each signal. Pseudo-ranges are calculated based on the time of transmission and time of reception indications, and a WLS solution location estimate is calculated based on the pseudo-ranges. Essentially the same procedure may be performed on signals transmitted by the mobile unit. Given the common time base between the fixed transceivers and the mobile unit, only two or more signals are required to determine the location estimate. Where GPS receivers are used to supply the common time base, location determinations can still be made when a GPS solution is unavailable.

Abstract: A method of stabilizing the action of a phased array antenna system in which the amplitudes and phases of signals applied to, or produced by, elements of the antenna are monitored, differences are detected and suitable weighting factors are determined and applied to remove the differences between the amplitudes and phases of the said signals.Transmitting and receiving antenna systems are described.

Abstract: A method and apparatus of improving user response time during cellular hand-offs and radio frequency changes in a Transmission Control Protocol/Internet Protocol (TCP/IP) mobile environment. In the mobile environment there is at least a mobile end station (20), a mobile data base station (22), a mobile data intermediate system (MDIS) (30) and a fixed end station (40). The MDIS (30) keeps track of the mobile end station (20) as it roams through the mobile environment. As a result, the MDIS (30) can distinguish between delays due to network congestion and delays due to cellular hand-offs. Further, the mobile data base station (22) informs the MDIS (30) of any changes in the radio frequency signal, thus allowing the MDIS (30) to also recognize delays due to changes in the radio frequency signal. With the knowledge of being able to identify the cause of the delays, the MDIS (30) is able to initiate or suppress a congestion control and recovery process.

Abstract: Remote units (113) that require locating are managed by a queue controller (180) such that the number and location of remote units (113) that are transmitting at increased power at any given time is limited. In particular, a queue controller (180) places identification information for remote units (113) requiring location onto queues (203) associated with base stations supplying reference pilots to the remote units (113). Additionally, identification (ID) information for the remote units (113) requiring location is placed onto queues (203) associated with base stations neighboring the base stations supplying the reference pilot to the remote units (113). The queues (203) operate on a first-in-first-out (FIFO) basis, that output remote unit ID at periodic intervals. Once all queues (203) have been emptied of the ID of a particular remote unit (113), location takes place for that remote unit (113).

Abstract: The location of a remote unit (113) within a wireless communication system (100) is determined by all base stations (101) within the wireless communication system (100) initiating a first page (wide-area location page) that is broadcast to the remote unit (113) over a paging channel. The serving and neighbor base stations are determined from the remote unit's (113) response to the wide-area location page, and those base stations are instructed to tune receiving elements to obtain data that will be transmitted by the remote unit (113) during location. A second message (Location Page Message) is then broadcast to the remote unit (113) via the serving base station (101). The Location Page Message instructs the remote unit (113) to periodically transmit a known Remote Unit Location Message (RULM) with increasing power levels for a predetermined number of times so that the remote unit's (113) location can be achieved.

Abstract: A radio communication system (100) employs a method and apparatus for providing packet data communications to a communication unit (e.g., 120). The communication system includes a system controller (102), a packet data router (101), and multiple base sites (103-109). Each base site serves a respective service coverage area (133-139) and the service coverage areas a grouped into multiple location areas (150-151). The packet data router receives a data packet intended for the communication unit and processes a transport protocol layer of the packet. The packet data router then determines whether the communication unit is presently involved in a packet data communication session based at least on information contained in the transport protocol layer of the packet.

Abstract: A method and apparatus for fraud detection is provided in which a remote unit within a communication system (100) transmits a Digital Supervisory Audio Tone (DSAT) at a transmission rate with a known maximum phase shift over time. When a fraudulent remote unit hijacks a traffic channel within the communication system (100), fraud detection is accomplished by calculating a maximum permitted (DSAT) phase shift (630) and determining if the reacquired DSAT has a phase shift greater than a permitted DSAT phase shift (635). When a reacquired remote unit's DSAT phase shift is greater than a permitted DSAT phase shift, appropriate fraud control methods are performed (640).

Abstract: A communication device (107) employs a method for determining signal quality of a communication channel (117) in a communication system (100). Upon receipt of a radio signal, a communication device (107), such as a portable radio, determines the signal quality of at least two portions (121, 124) of the communication channel (117) over which the radio signal was transmitted. The communication device (107) then determines which of the determined signal qualities is lowest and selects the lowest determined signal quality as the signal quality of the communication channel (117). The communication device (107) can then use the selected channel quality in the handoff decision-making process.

Abstract: A subscriber's signal (117) is removed from a composite signal (120) received in a serving base station (100), where the subscriber (113) is not in communication with the serving base station (100). The subscriber's signal (117) is removed from the composite signal (120) by receiving information regarding potential interferers in communication with the non-serving base stations (150). Next, a most reliable signal is determined from the potential interferers in communication with non-serving base stations (150-155). The most reliable signal is then removed from the composite signal (120).

Abstract: A feed forward amplifier (200) comprises a main signal path (201), an error signal path (203), and a third signal path (205). In the preferred embodiment of the present invention, the third signal path (205) comprises a gain and phase adjuster (245), delay circuitry (249), summing circuitry (251), and an error cancellation detector (255). The third signal path (205) is designed to match passive components in a component section (207) of the main signal path (201) to the error signal path (203). Gain and phase adjustments are made by the gain and phase adjuster (235) to minimize the RSSI of the error components within the input signal (253).

Abstract: During a wireless communication of data in which modems (21, 24) are in use, a method of handing off the communication link (32) is described. The communication link (32) is handed off from a source base site (22) to a target base site (23). An interworking function (33) is then transfered from a source interworking unit (25) to a target interworking unit (26) by transfering protocol status (42) such as transmission control protocol. A cut over (34) from the source modem (21) to a target modem (24) is conducted once the interworking function (33) is transfered.

Abstract: In a receiver (10) of a code division multiple access system, a method of processing a received signal including reading a first and second data item from a first memory (50), at least one of the first and second data items associated with Walsh data; performing a first arithmetic operation on the first and second data items to produce a first result; performing a second arithmetic operation on the first and second data items to produce a second result; and storing the first and second result into a second memory (52) while reading a third and fourth data item from the first memory (50).

Abstract: Providing communications service to a coverage hole (22) in a DS-CDMA cellular communication system (50) involves an OMC (52) determining the transmitters (134-144) in adjacent cells (122-132) to the coverage hole (22). The OMC (52) places each of the transmitters (134-144) in the adjacent cells (122-132) in a power on demand mode (92). The OMC (52) then selects at least one, but less than all of the transmitters (134-144) to increase power to a pilot channel. The selected transmitter(s) is chosen base on one or more of the following factors, the transmitter's level of unused power, the interference level at the transmitter and the position of the transmitter.