Trimble Navigation Limited

Kevin Marvin

John R Coffee

David A Dye

Robert W Lewis

Richard W Rudow

Robert F Allen

Robert D Sleeper

Mark L Kirchner

William A Tekniepe

Mark Billings

Terry Gin

David Anderson

A method and system for efficient extended data communications using a GPRS (General Packet Radio Service) carrier network. In a communications system having a server and client device coupled by a GPRS network, a communication session is initiated by the client. A combination of data packet transmission frequency adjustment and the transmission of 'keep alive' packets are used to prevent carrier network time-out of the communication session. In multiple server environments such as those using load sharing, a queuing mechanism is provided for outbound messages to client devices.

Method and system for efficient extended data communications using GPRS

A vehicle fleet management information system identifies location and direction of movement of each vehicle in a fleet in real-time, and automatically reports such information, as well as status of predetermined events in which the vehicle is engaged, directly to the fleet manager. One aspect relates to automated reporting of status of a ready mix slurry material truck having a mixer drum. A sensor detects the begin pour event by detecting the mixer drum being run in a discharge direction.

Vehicle tracking, communication and fleet management system

A vehicle fleet management information system for identification of location and direction of movement of each vehicle in the fleet in real-time and automatic communication directly with management offices to report its location and heading, and status of predetermined events in which the vehicle may be engaged. One example is a cement delivery truck which monitors location, speed and status information such as start pour, pouring, end pour, wash and leave job, and automatically transmits this information with a management office without requiring affirmative action by the vehicle operator.

A vehicle fleet management information system identifies location and direction of movement of each vehicle in a fleet in real-time, and automatically reports such information, as well as status of predetermined events in which the vehicle is engaged, directly to the fleet manager. Each fleet vehicle has an assigned time slot to transmit its reporting information over a communications network without interfering with transmissions from other vehicles in their own respective time slots. A timing control phase lock loop (PLL) provides precise time synchronization for timing corrections from a global positioning system (GPS) based time reference. A dual band full-duplex interface of the network has TDMA on one-half and broadcast on the other half. Microprocessor time processing units in components of the network perform precise clock synchronization. Space diversity performed on received vehicle transmitted messages avoids data corruption. Different vehicles have different periodic transmission intervals, by dynamically allocating the slots for various update rates. Auxiliary reporting slots enable prompt reporting of important data by the respective vehicle transmitters independent of the slower periodic transmission intervals.

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Gilbert, AZ, United States of America

Kevin Marvin