Fixed site monitor using a location-based communications network

• US 5,719,563 A
• Filed: 07/07/1995
• Issued: 02/17/1998
• Est. Priority Date: 07/07/1995
• Status: Expired due to Fees

• Current Assignee: TeleTrac Incorporated (Vontier Corp.)
• Original Assignee: TeleTrac Incorporated (Vontier Corp.)
• Inventors: Thompson, Darwin O. Jr.
• Primary Examiner(s): Hofsass, Jeffery
• Assistant Examiner(s): WONG, ALBERT KANG
• Application Number:
  US08/499,415
• Time in Patent Office: 956 Days
• Field of Search: 340/870.05, 340/825.08, 340/870.06, 340/870.02, 340/870.04, 340/870.07, 340/870.11, 340/870.13, 340/870.16, 235/383, 235/385, 364/464.04, 342/44, 455/67.1, 455/67.4
• US Class Current: 340/870.02
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

A method for monitoring and controlling remote site parameters by using a location-based communications network. The system uses monitoring and control devices that are located at remote locations and controlled and monitored either at a control center or at a workstation which can request data responses and send commands to the remote sites based on the response data received from the remote sites.

Claims

1. A method for monitoring a device located at a remote site, comprising the steps of:

(a) transmitting a polling message from a transmitting site to the subscriber unit in response to an access request message, the polling message comprising the identification number of the subscriber unit, data defining a unique time interval for transmission of a response message from the subscriber unit located at the remote site, and a data request which defines the requested data;

(b) transmitting a response message from the subscriber unit located at the remote site in response to the polling message during the time interval to a plurality of receiving sites, the response message comprising measurements made by the devices coupled to the subscriber unit located at the remote site, the receiving sites each receiving the response message at different times;

(c) determining the location of the subscriber unit from the time difference of arrival of the response message at the receiving sites; and

(d) analyzing the measurements made by the devices coupled to the subscriber unit at the remote site, the step of analyzing further comprising storing the measurements, comparing the stored measurements to previously known values for the measurements, using the location data and the stored measurements to automatically determine whether a measurement has changed at a remote site, and deciding whether to perform additional actions based on whether a measurement has changed and the amount of the change.

2. The method of claim 1, wherein the method further comprises the steps of generating an access request message at a workstation located remotely with respect to the subscriber unit, the access request message comprising an identification number unique to the subscriber unit, and using the identification number to generate the polling message.

3. The method of claim 1, wherein the method further comprises the steps of monitoring at least one measurement device at the remote site, and generating a mobile information service access request based on the device measuring a parameter which falls outside of pre-selected limits for that parameter.

4. The method of claim 1, wherein the method further comprises the steps of receiving the response message at a control center and generating a repair message to at least one mobile unit in response to the response message.

5. The method of claim 4, wherein the repair message is sent to the most desirable repair unit, the most desirable repair unit status determined by location, utilization status, availability, and capabilities of the repair units.

6. The method of claim 1, wherein the polling message is generated at a control center.

7. The method of claim 1, wherein the method further comprises the steps of transmitting an access request message from a subscriber unit located at a remote site to one or more receiving sites, the access request message comprising an identification number unique to the subscriber unit.

8. A method for controlling a device located at a remote site, comprising the steps of:

(a) generating a polling message, the polling message comprising the identification number of a subscriber unit located at the remote site, data defining a unique time interval for transmission of a response message from the subscriber unit, and a data request which tells the subscriber unit which data is to be sent in the response message;

(b) polling the subscriber unit at the remote site by transmitting the polling message;

(c) transmitting a response message from the subscriber unit in response to the polling message during the time interval to at least three receiving sites, the response message comprising measurements made by the devices at the remote site;

(d) locating the remote site from the time difference of arrival of the response message at three receiving sites;

(e) compiling the measurements made by the devices at the remote site, the step of compiling further comprising storing the measurements, comparing the stored measurements to previously known values for the measurements, using the location data and the stored measurements to automatically determine whether a measurement has changed at a remote site, and deciding whether to perform additional actions based on whether a measurement has changed and the amount of the change; and

(f) generating a command to be sent to the remote site to change at least one parameter at the remote site based on the measurements received from the remote site.

9. The method of claim 8, wherein the method further comprises the step of generating an access request message at a workstation located remotely with respect to the subscriber unit, the access request message comprising an identification number unique to the subscriber unit, and using the identification number to generate the polling message.

10. The method of claim 8, wherein the method further comprises the steps of monitoring at least one measurement device at the remote site, and generating a mobile information service access request based on the device measuring a parameter which falls outside of pre-selected limits for that parameter.

11. The method of claim 8, wherein the polling message is generated at a control center.

12. The method of claim 8, wherein the method further comprises the step of requesting access to a mobile information service at pre-defined intervals by transmitting an access request message from a subscriber unit at a remote site to at least one receiving site, the access request message comprising an identification number unique to the subscriber unit located at the remote site.

13. The method of claim 8, wherein the method further comprises the steps of generating a second response message after the command has been executed at the remote site to verify that the command has been executed.

14. The method of claim 8, wherein the subscriber unit is coupled to an interface which allows for the data that can be sent in the response message to be entered manually.