Motorola Corporation

Other

Paul M Bocci

Robert W Furtaw

Bradley Michael Hiben

Richard A Comroe

Arun Sobti

James A McDonald

Alan L Wilson

Carl M Pietrzak, Jr

Stephen H Sanders, Iii

Gary W Grube

Terence Edward Sumner

Eric F Ziolko

John M Gilbert

Walter F Anderson

Kevin M Cutts

Keith I Mulford

Richard H Noens

John E Buchalo

Lawrence E Feldman

Scott J Propp

James G Edkins

Robert W House

Larry E Feldman

James R Wojnarowski

A method and apparatus for calculating the travel time of a vehicle as it transits through multiple locations. The method and apparatus includes a device for detecting a radio signal from a vehicle, attaching information to the radio signal, and transmitting a message packet with the signal and attached information to a central server. The central server stores the message packet. The central server compares the information in the message packet against other stored message packets received from multiple locations. When matching information is found, an algorithm is run to compute a vehicle travel time between two locations.

Method and apparatus for vehicle traffic time calculation

A dispatch controller (103) located logically external to an existing telephone network (101) is coupled to the existing telephone network. When an originating communication device (e.g., 111) desires to initiate a dispatch call, the originating device transmits a call request to the existing telephone network, wherein the call request includes an identification (ID) of the originating device and a target address associated with the dispatch controller. The existing telephone network provides the call request to the dispatch controller. Upon receiving the call request, the dispatch controller retrieves dispatch-related information from a database (105) coupled to the dispatch controller based on the originating device's ID. Based on the retrieved dispatch-related information, the dispatch controller identifies a group of target communication devices (e.g., 107-110) for the dispatch call. The dispatch controller then generates and sends control signals to the originating device and the group of target devices via the existing telephone network to establish and manage the dispatch call.

Method and apparatus for providing dispatch service to an existing

Group communications between subscribers (20, 22) affiliated with a terrestrial communication system (12, 14) and subscribers (46, 48) affiliated with a satellite communication system (10) is begun when a subscriber has initiated a group communication request. The request is provided, via a controller (i.e., a terrestrial system controller or satellite system controller depending on which communication system the requesting subscriber is affiliated with), to a systems interface (36). Upon receiving the request, the systems interface determines whether subscribers that are identified to participate in the group communication are located in the terrestrial system and/or the satellite system. If the group of subscribers have members in both communication systems, the systems interface establishes satellite communication links for each subscriber affiliated with the satellite communication system and establishes a terrestrial communication link for subscribers affiliated with a terrestrial communication system. Once the communication links are established, the systems interface arbitrates transmissions of the group of subscribers. The arbitration of transmissions insures that each subscriber in the group of subscribers receives the transmission.

Method and apparatus for establishing group communications between

Apparatus for providing dispatch service to an existing telephone network

Signal sources provide frames (302-303) to a comparator (206). For each frame, codeword error statuses for each of the codewords and a frame error status (313-314) are determined. Codeword error statuses are provided for priority sets of codewords (306, 308) and are not provided for non-priority sets of codewords (311, 312). The codeword error statuses for members of the priority set of codewords for each frame are compared, wherein the members have substantially identical codeword identifications. Selected priority codewords are produced by selecting members of the priority sets having favorable codeword statuses. Furthermore, the frame error statuses for each frame are also compared. Selected non-priority codewords are produced by selecting the non-priority set of codewords corresponding to a favorable frame error status. The selected priority codewords and the selected non-priority codewords are then provided as the favorable signal representation (304). Alternatively, only frame error statuses may be provided.

Method for providing a favorable signal representation

In a digital communication system (100), a second message (309) may be substituted for a first message (301) by detecting a suitable transition point and beginning transmission of the second message at this transition point. In a frame-synchronous digital communication system, this transition point is a frame boundary within the first message.

Message substitution in a digital communication system

A method of allowing use of small, low-power communication systems (20) within the coverage area (11) of larger trunked communication systems. A low-power communication system re-uses the same communication resources used by the larger trunked system whenever sufficient distance exists between large system communication units and the low power system so as to avoid interference. Large system communication units may also be constructed to operate in a dual mode format so as to transmit and receive in a low power mode and on re-used resources, whenever near a low power system or to transmit and receive in a high power mode whenever else necessary.

On-site system frequency sharing with trunking system

A data communication protocol permits efficient and cost-effective transmission of control and ancillary messages among the components of a communication system infrastructure (200). Messages are organized into Infrastructure Control Words (300) with accompanying Format Identifiers (304), and interleaved with voice and data segments (707) to form message streams (700) that are transmitted from one infrastructure component, such as a base station (201), to another infrastructure component, such as a Digital Interface Unit (202).

Data communication protocol

Shown, herein, is a method of allowing use of small, low-power communication systems within the service coverage area of larger trunked systems. The small, low-power systems are constructed to reuse at least some of the communication resources, also used by the larger system. The large system measures signal strength values of large cell communication units and transfers such values to the small systems. A small system compares the transferred values with a threshold and when the threshold is exceeded, reuses the communication resources under a TDM format within the small system.

On-site/trunking system frequency sharing

Shown, herein, is a method of allowing use of small, low-power communication systems within the service coverage area of larger trunked systems. The small, low-power systems are constructed to reuse at least some of the inbound frequencies of communication resources, also used by the larger system. The large system measures signal strength values of large cell communication units and transfers such values to the small systems. A small system also measures the signal strength and compares the measured and transferred values with thresholds and when the thresholds are exceeded, reuses the communication resources under a TDM format within the small system.

Near-field on-site/trunking system frequency sharing

A way of allowing small, low-power communication units to reuse trunked system communication resources within the service coverage area of the larger trunked system without experiencing significant interference from the trunked system. The low power units (requestors and targets) avoid interference through spread spectrum transmissions.

On-site system frequency sharing with trunking systems using spread

A layered session data unit frame (300) is provided wherein a first frame (200), designated a session data unit('SDU'), containing user information (209), a link control field (205) and an encryption field (207), is divided into a plurality of smaller frames (321, 323), each having an information field and designated a link data unit('LDU'). According to the invention, the SDU user information (209) is allocated into the information fields (211, 213) of the plurality of LDU's. The SDU link control field (205) is divided into a plurality of sub-fields and imbedded into the information fields of a first group of LDU's. The SDU encryption field (207) is divided into a plurality of sub-fields and imbedded into the information fields of a second group of LDU's. The sub-fields may be distributed throughout the LDU's in a generally uniform fashion. For instance, where the user information comprises coded voice words, the sub-fields may be separated by 30 msec words such that voice may be produced during the transmission of the field without any audio delay.

Layered session data unit frame

In an RF communication system, a method for developing and communicating usage context information. When an inbound communication (110) is received from a communication unit (107), a repeater (101) at a base site (100) retransmits the received communication as an outbound signal (114), including usage context information interleaved with the information signal. Communication units are informed of communications of interest occurring over other communication resources without the need for sequential monitoring.

Method for developing and transmitting usage context information in an

In a mobile communications system, a plurality of base stations may receive the same signal, whereby the 'best' reception may be determined. The plurality of received digital signals are combined to form a majority signal. Each of the received digital signals is compared to the majority signal to estimate the bit-error-rate (BER) of each received signal. If the difference between the highest and lowest BER is less than a predetermined threshold, the majority signal is selected for reception. Conversely, if the BER difference is greater than the predetermined threshold, the received digital signal with the lowest BER is selected for reception. Thus, the signal with the lowest BER is selected to provide the best possible communications.

Method and apparatus for selecting a digital signal from a plurality of

A data detector is disclosed wherein a received signal is analyzed to determine its statistical characteristics. These characteristics are compared to a predetermined statistical distribution. If the signal is statistically close to the statistical characteristics of a known signal a detect signal is generated and the received signal is passed for further processing and reception.

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Roselle, IL, United States of America

Paul M Bocci