Integrated proximity warning system and end of train communication system

Claim 2

A proximity warning system (PWS) unit for providing a warning of trains traveling in a common radio frequency region, the proximity warning system unit cooperating with a locomotive cab unit (LCU) which communicates with an end of train (EOT) unit and comprising: location means for determining current location data; a PWS receiver for receiving location data from other trains; an EOT receiver for receiving data from the end of train unit; control means for monitoring said PWS receiver and said EOT receiver, said control means using said current location data and location data from other trains to calculate proximity to the other trains; display means controlled by the control means for displaying the calculated proximity to the other trains; and a transmitter controlled by said control means to transmit said current location data and identification data in a PWS message to other trains, said control means including carrier sense multiple access logic for permitting simultaneous reception from both said PWS receiver and said EOT receiver and for permitting transmission of the PWS message only when said PWS receiver and said EOT receiver are idle.

Claim 3

The proximity warning system unit recited in claim 1 wherein said location means comprises a global position system (GPS) receiver which provides current location data in latitude and longitude and speed and direction data of the locomotive, said PWS message further including the speed and direction data.

Claim 4

The proximity warning system unit recited in claim 1 wherein said location means comprises a track location system providing milepost data to said control means, further comprising speed and direction sensing means providing inputs to said control means, said control means computing a current location a function of said milepost data and speed, said PWS message further including speed and direction data.

Claim 5

The proximity warning system unit recited in claim 1 wherein said control means includes a PWS central processing unit (CPU), said LCU having a separate LCU CPU, the LCU CPU controlling communications with the EOT unit and communicating with the PWS CPU to suppress a PWS message transmission in the event of the reception of a EOT unit message.

Claim 6

The proximity warning system unit recited in claim 4 wherein the EOT unit is equipped with a receiver for two-way communication between the LCU and the EOT unit, said LCU CPU further acting to suppress a PWS message by the PWS CPU in the event of a transmission by the LCU to the EOT unit.

Claim 7

A proximity warning system (PWS) unit for providing a warning of trains traveling in a common radio frequency region, the proximity warning system unit cooperating with a locomotive cab unit (LCU) which communicates with an end of train (EOT) unit and comprising: location means for determining current location data; a PWS receiver for receiving location data from other trains; an EOT receiver for receiving data from the end of train unit; control means for monitoring said PWS receiver and said EOT receiver, said control means using said current location data and location data from other trains to calculate proximity to the other trains; display means controlled by the control means for displaying the calculated proximity to the other trains; a transmitter controlled by said control means to transmit said current location data and identification data in a PWS message to other trains, said control means including carrier sense multiple access logic to control transmission of the PWS message only when said PWS receiver and said EOT receiver are idle; and a second location means in the EOT unit, said EOT unit transmitting to the LCU a current location of an end of the train.

Claim 8

A proximity warning system (PWS) unit for providing a warning of trains traveling in a common radio frequency region, the proximity warning system unit cooperating with a locomotive cab unit (LCU) which communicates with an end of train (EOT) unit and comprising: location means for determining current location data; a PWS receiver for receiving location data from other trains; an EOT receiver for receiving data from the end of train unit; control means for monitoring said PWS receiver and said EOT receiver, said control means using said current location data and location data from other trains to calculate proximity to the other trains; display means controlled by the control means for displaying the calculated proximity to the other trains; a transmitter controlled by said control means to transmit said current location data and identification data in a PWS message to other trains, said control means including carrier sense multiple access logic to control transmission of the PWS message only when said PWS receiver and said EOT receiver are idle; and a second location means in the EOT unit, said EOT unit transmitting to the LCU a current location of an end of the train.

Claim 9

The proximity warning system unit recited in claim 6 wherein the PWS message includes an EOT identification (ID) and the EOT unit includes a receiver for responding to interrogations from other locomotive LCUs to transmit the current location of the end of the train.

Claim 12

A proximity warning system (PWS) for warning trains traveling in a common radio frequency region of the proximity of other trains, said PWS comprising a PWS unit mounted on each of cooperating locomotives in the common radio frequency region, the PWS unit having an integrated function with a locomotive cab unit (LCU) which communicates with an end of train (EOT) unit and comprising: location means for determining current location data; a PWS receiver for receiving PWS messages from other trains, a PWS message including locomotive identification (ID), location data, direction data, speed data, and railroad ID; an EOT receiver for receiving data from the end of train unit; control means for monitoring said PWS receiver and said EOT receiver, said control means using said current location data and location data from other trains to calculate proximity to the other trains; display means controlled by the control means for displaying the calculated proximity to the other trains, locomotive ID, direction data, speed data, and railroad ID for each of said other trains; and a transmitter controlled by said control means for transmitting said current location data, direction data, speed data, and identification data in a PWS message to other trains, said control means including carrier sense multiple access logic for permitting simultaneous reception from both said PWS receiver and said EOT receiver and for permitting the transmission of said PWS message only when said PWS receiver and said EOT receiver are idle.

Claim 13

A proximity warning system (PWS) for warning trains traveling in a common radio frequency region of the proximity of other trains, said PWS comprising a PWS unit mounted on each of cooperating locomotives in the common radio frequency region, the PWS unit having an integrated function with a locomotive cab unit (LCU) which communicates with an end of train (EOT) unit and comprising: location means for determining current location data; a PWS receiver for receiving PWS messages from other trains, a PWS message including locomotive identification (ID), location data, direction data, speed data, and railroad ID; an EOT receiver for receiving data from the end of train unit; control means for monitoring said PWS receiver and said EOT receiver, said control means using said current location data and location data from other trains to calculate proximity to the other trains; display means controlled by the control means for displaying the calculated proximity to the other trains, locomotive ID, direction data, speed data, and railroad ID for each of said other trains; and a transmitter controlled by said control means for transmitting said current location data, direction data, speed data, and identification data in a PWS message to other trains, said control means including carrier sense multiple access logic for permitting simultaneous reception from both said PWS receiver and said EOT receiver and for permitting the transmission of said PWS message only when said PWS receiver and said EOT receiver are idle.

Claim 14

The proximity warning system recited in claim 9 further comprising a repeater PWS unit mounted at a fixed location within the common radio frequency region to improve or extend a direct locomotive to locomotive communications coverage, said repeater PWS unit comprising: a second PWS receiver for receiving PWS messages; a second transmitter for transmitting PWS messages; and a second control means connected to said second PWS receiver and second transmitter for decoding received PWS messages, delaying the decoded PWS messages, and then retransmitting the PWS messages on said second transmitter, said second control means including carrier sense multiple access logic to retransmit the PWS messages only when the second PWS receiver is idle.

Claim 15

The proximity warning system unit recited in claim 6 wherein said location means comprises a global position system (GPS) receiver which provides current location data in latitude and longitude and speed and direction data of the locomotive, said PWS message further including the speed and direction data.

Claim 16

The proximity warning system unit recited in claim 6 wherein said location means comprises a track location system providing milepost data to said control means, further comprising speed and direction sensing means providing inputs to said control means, said control means computing a current location a function of said milepost data and speed, said PWS message further including speed and direction data.

Claim 17

The proximity warning system unit recited in claim 6 wherein said control means includes a PWS central processing unit (CPU), said LCU having a separate LCU CPU, the LCU CPU controlling communications with the EOT unit and communicating with the PWS CPU to suppress a PWS message transmission in the event of the reception of a EOT unit message.

Claim 18

The proximity warning system unit recited in claim 13 wherein the EOT unit is equipped with a receiver for two-way communication between the LCU and the EOT unit, said LCU CPU further acting to suppress a PWS message by the PWS CPU in the event of a transmission by the LCU to the EOT unit.