Abstract: In a code division multiple access (CDMA) spread spectrum cellular communication system in which a mobile station user communicates with another system user via at least one base station, wherein each base station transmits a common pilot signal of a different PN offset with respect to other base stations in said system, a method for merging neighbor lists to account for false indications of signal strength due to topography. The merged list, included as part of the Neighbor List Update Message, is arrived at by first measuring pilot signal strengths and phase delays received by the mobile station and reporting this information to the mobile telephone switching office. At the mobile telephone switching office, pilots whose phase delay indicates a large round trip delay time are ignored in subsequent calculations. Then a neighbor list union is generated as the union of all predetermined neighbor lists corresponding to said received pilot signals.

Abstract: Method and apparatus to prevent system deadlock in a dispatch system by monitoring link activity. The dispatch system is comprised of a set of remote units which communicate with each other by broadcasting one at a time to the group. A remote unit communicates with the other remote units through at least one base station. A communications manager grants a remote unit exclusive system talker status upon request through the base station servicing the requesting remote unit. The base station monitors a series of data from the remote unit designated as the system talker to detect voice activity. The base station sends a surrogate request to the communications manager to relinquish the system talker privilege if the voice activity falls below a predetermined threshold.

Abstract: In a push-to-talk dispatch system, a method and apparatus for providing an accelerated response to a push-to-talk origination message. A first base station allocates a first set of equipment to support a push-to-talk connection. A first system controller allocates a second set of equipment to support the push-to-talk connection. Upon receipt of a push-to-talk origination message from a first remote unit, the first base station transmits an immediate response to the first remote unit, instructing it to communicate through the first set of equipment and the second set of allocated equipment.

Abstract: A system and method for determining a route of travel and associated mileage of a vehicle is disclosed. The system records a vehicle's identification number, location, and odometer mileage transmitted via satellite to a fixed station. The location data is provided to a processor which determines an estimated route of travel by said vehicle using a routing program. The estimated route is comprised of a plurality of position segments, each position segment having a corresponding mileage and average expected speed. The route of travel may be checked for accuracy by comparing the estimated route mileage to the odometer mileage. If a significant difference is found, a diagnostic procedure is performed which attempts to correct the mismatch by evaluating alternate routes of travel. If the alternative route mileage agrees with the actual odometer miles within a predetermined threshold, the new route and associated mileage is used as the "true" route taken by the vehicle.

Abstract: A method and apparatus to provide access to a dispatch system is disclosed. A communications manager (40) grants an exclusive system talker privilege to one remote unit (10) in the system at a time. After a remote unit (10) requests and is designated as the exclusive system talker, no other remote unit (20, 22) may transmit for a first pre-determined amount of time. After the first pre-determined time has elapsed, any other remote unit (20, 22) may request the exclusive system talker privilege and become the exclusive system talker. The exclusive system talker privilege is revoked by the communications manager (40) to any remote unit who retains the exclusive system talker privilege for more than a second pre-determined amount of time. The exclusive system talker privilege is also revoked upon the release of a push-to-talk button on a remote unit (10).

Abstract: A method and apparatus for controlling various functional elements in a digital telephone system using state determination from an echo canceller. An echo canceller is used to evaluate which one of five talk states two speakers are engaged in during a telephone conversation. This state determination information is used to control a tone detector function, a noise suppressor function, an adaptive equalizer function, a transmission mute function, and a vocoder encoder function within a vocoder. During the talk state where the far-end speaker is active and the near-end speaker is inactive, the echo canceller provides a signal which disables background noise estimates from being performed in the noise suppressor and the vocoder encoder. The same signal is used to disable the tone detector and to enable the transmission mute function during this talk state.

Abstract: A private communication network through which a plurality of member users communicate using the public switched telephone network (PSTN) is disclosed herein. Each member user utilizes either a modified land line telephone directly connected to PSTN, or uses a modified mobile telephone operatively coupled to the PSTN through a wireless communication system. The private communication network includes network call manager having a telephone network interface for establishing a telephone connection with each of a plurality of telephone lines of the PSTN. Each of the plurality of telephone lines is associated with one of the plurality of member users. The network call manager further includes a switch matrix, coupled to the telephone network interface, for providing an information signal received from an active member user over a selected telephone line to the remaining non-active member users.

Abstract: To reduce the power consumption of a remote unit in a dispatch system the remote unit enters a dormant state. A base station transmits a forward link broadcast signal and monitors a common access channel. A first remote unit continually receives and decodes the forward link broadcast signal and determines whether said forward link broadcast signal comprises active signals. If the remote unit determines that the forward link broadcast signal comprises no active signals for some a duration T.sub.1, the first remote unit enters a dormant mode. In the dormant mode the remote unit sporadically receives and decodes said forward link broadcast signal. If this remote unit or any other remote unit on the same net presses a push to talk button, it transmits a message on the common access channel. In response, every remote unit on the net which is in a dormant state exits the dormant state and continually monitors the forward link broadcast signal.

Abstract: In a dispatch system, power of the forward link broadcast channel transmitted from a base station is controlled such that the power level is the minimum necessary and such that transmission of the forward link broadcast channel is terminated if no remote unit is located within the coverage area of the base station. In addition to transmitting a forward link broadcast signal, the base station monitors an access channel. A first remote unit in the base station coverage area receives and decodes the forward link broadcast signal. The first remote unit determines a signal quality of said forward link broadcast signal. If the signal quality is unacceptable, the remote unit transmits a power request access message. The base station responds to the request by increasing the transmission power of forward link broadcast channel. If no requests are received at the base station, the forward link broadcast channel is slowly decreased to a minimum.

Abstract: Synchronization and bit count integrity of a synchronous data stream is preserved end to end even as it is transmitted via a medium which does not preserve the synchronous nature of the synchronous data stream. A terminal equipment unit produces a constant rate bit stream which is provided to a communications unit. The communications unit produces first, second, and third data frames comprising, respectively, first, second, and third set of bits from the constant rate bit stream and first, second, and third length fields. The first, second, and third data frames are transmitted to a base unit which places the first set of bits from the first frame into a queue. A set of fill bits equal to the maximum number of bits contained in any frame is then placed into the queue. The base unit then determines the number of bits in the second set of bits of the third data frame, based on the first length field value and the third length field value.

Abstract: A system for monitoring and adjustment of control unit parameter settings of vehicle electronic control units. The monitoring system may be implemented in a vehicle in which are incorporated one or more electronic control units for regulating one more operational parameters of the vehicle in accordance with corresponding control unit parameter settings. In an exemplary implementation the vehicle is equipped with a mobile communications terminal (MCT), which receives from a base station a list of operational parameters to be monitored. Each of the electronic control units, as well as a memory unit, are connected to an internal data link of the vehicle. When a parameter value within the memory unit corresponding to a given control unit is changed, a message is provided to the base station specifying the value currently registered by the control unit. The currently registered value is then compared to an expected parameter value, and an error message is generated if disagreement exists therebetween.