Proximity monitoring communication system

• US 20030063003A1
• Filed: 09/28/2001
• Published: 04/03/2003
• Est. Priority Date: 09/28/2001
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Alberth, William P. Jr., Bero, Robert J.
• Granted Patent: US 6,563,427 B2
• Time in Patent Office: Days
• US Class Current: 340/573.1
• CPC Class Codes: G08B 21/0225 Monitoring making use of different thresholds, e.g. for different alarm levels
• CPC Class Codes: G08B 21/0227 System arrangements with a plurality of child units
• CPC Class Codes: G08B 21/023 Power management, e.g. system sleep and wake up provisions
• CPC Class Codes: G08B 21/0247 System arrangements wherein the alarm criteria uses signal strength

Abstract

A method of personal location monitoring in a wireless communication system operating on a local area network. The method includes initializing a master communication device and a slave monitor device on the local area network. A next step transmitting a signal on the local area network by the slave monitor device. A next step includes the communication device receiving the signal on the local area network and measuring the signal strength which is compared to a threshold. A next step includes triggering an alarm in the communication device when the signal strength falls below the threshold, indicating that the monitor device is straying from the proximity of the local area network.

Claims

1. A method of proximity monitoring in a wireless communication system operable on a local area network, the method comprising the steps of:

providing at least one communication device as a master unit in the local area network and at least one monitor device as a slave unit in the local area network;

initializing the at least one communication device and the at least one monitor device in the local area network;

transmitting a signal on the local area network by the at least one monitor device;

receiving the signal on the local area network by the at least one communication device; and

triggering an alarm in the at least one communication device when the signal is no longer received, indicating that the at least one wireless monitor device is straying from the proximity of the local area network.

2. The method of claim 1, wherein the receiving step includes measuring the signal strength by the at least one communication device, and further comprising a step of comparing the signal strength to a threshold, and wherein the triggering step includes triggering an alarm when the signal strength falls below the threshold.

3. The method of claim 1, wherein the initializing step includes the at least one communication device reading a unique identifier for each monitor device.

4. The method of claim 1, wherein in the providing step the at least one wireless monitor device includes a power control, and wherein the triggering step includes triggering the alarm when the power control is defeated.

5. The method of claim 4, further comprising the steps of:

suspending monitoring of the slave unit by the master unit;

saving programming of the master and slave unit;

instructing the slave unit to alarm only if its power is interrupted;

releasing the suspend function;

attempting recovery and re-initialization of all previously slaved units by the master unit; and

informing a user of the master unit whether the attempting step is successful.

6. The method of claim 2, wherein the transmitting step includes the at least one communication device transmitting a second signal on the local area network, the receiving step includes the at least one wireless monitor device measuring a strength of the received second signal, and the triggering step includes triggering an alert on the at least one wireless monitor device when the received second signal strength is less than a second threshold.

7. The method of claim 6, wherein the triggering step includes the threshold being less than the second threshold such that the triggering of the alert occurs before the triggering of the alarm.

8. The method of claim 6, further comprising the step of slaving each of the at least one wireless monitor devices to the at least one wireless communication device with the strongest received second signal from the receiving step.

9. The method of claim 1, wherein the providing step includes first and second wireless communication devices being operable on a wide area network, each communication device supporting separate local area networks, respectively, and further comprising the steps of:

communicating between the first and second wireless communication device on the wide area network for transferring the at least one monitor device therebetween, transferring the at least one monitor device from control of the first communication device to the second communication device, and allowing for a time-out period for the at least one monitor device to transfer to the local area network, and wherein the triggering step includes triggering the alarm if the time-out period expires before the transferring step is complete.

10. The method of claim 1, wherein the providing step includes first and second wireless communication devices being operable on a wide area network, each communication device supporting separate local area networks, respectively, wherein after the comparing step further comprising the steps of:

if the signal strength from the slave unit to the master unit is no longer detected,

querying the other communication devices on the wide are network to determine if any of these communication devices can detect the particular slave unit in question on their associated local area network;

waiting a timeout period for all such other communication device to respond affirmatively; and

transferring master authority over the slave unit to any responding other communication device that responds affirmatively during the waiting step.

11. A method of proximity monitoring in a wireless communication system operable on a local area network, the method comprising the steps of:

providing at least one communication device as a master unit in the local area network and at least one monitor device as a slave unit in the local area network, each of the at least one communication devices having an alarm and each of the at least one monitor devices having a unique identifier, an alert and a power control;

initializing the at least one communication device and the at least one monitor device in the local area network;

transmitting a signal on the local area network by the at least one monitor device;

receiving the signal on the local area network and measuring the signal strength by the at least one communication device;

comparing the signal strength to a threshold; and

triggering an alarm in the at least one communication device when the signal strength falls below the threshold, indicating that the at least one wireless monitor device is straying from the proximity of the local area network or the power control has been defeated.

12. A proximity monitoring communication system for a wireless local area network, the system comprising:

at least one wireless monitor device operable as a slave unit in the local area network, the at least one wireless monitor device including a unique identifier for each monitor device, the at least one wireless monitor device transmits a signal on the local area network; and

at least one wireless communication device operable as a master unit of the local area network, the at least one wireless communication device operable to detect the received signal from the at least one wireless monitor device, wherein loss of detection of the received signal triggers an alarm on the at least one wireless communication device, indicating that the at least one wireless monitor device is straying from the proximity of the local area network.

13. The system of claim 12 wherein the at least one wireless communication device is operable to measure a strength of the received signal from the at least one wireless monitor device, wherein a received signal strength of less than a threshold triggers the alarm.

14. The system of claim 12, wherein the at least one wireless monitor device includes a power control, wherein if the power control is defeated while the at least one monitor device is in communication with the local area network, the alarm will be triggered in the at least one wireless communication device.

15. The system of claim 14, wherein the master unit can suspend monitoring of the slave unit, wherein the master unit saves programming of the master and slave unit and instructs the slave unit to alarm only if its power is interrupted, and wherein the master unit releases the suspend function by attempting to recover and re-initialize all previously slaved units and informing a user of the master unit whether the attempt at recovery and re-initialization is successful.

16. The system of claim 13, wherein the at least one wireless communication device transmits a second signal on the local area network, the at least one wireless monitor device being operable to measure a strength of the received second signal from the at least one wireless communication device, wherein a received second signal strength of less than a second threshold triggers an alert on the at least one wireless monitor device.

17. The system of claim 16, wherein the threshold is less than the second threshold such that the alert occurs before the alarm.

18. The system of claim 16, wherein each of the at least one wireless monitor devices will slave to the at least one wireless communication device with the strongest received second signal.

19. The system of claim 12, wherein there are first and second wireless communication devices being operable on a wide area network, each communication device supporting separate local area networks, respectively, and wherein the first communication device communicates to the second communication device on the wide area network that the at least one monitor device will be transferred from the local area network of the first communication device to the local area network of the second communication device, and wherein the first communication device provides a timeout period for the at least one monitor device to transfer to the local area network of the second communication device before the alarm is triggered.

20. The system of claim 12, wherein there are first and second wireless communication devices being operable on a wide area network and having associated local area networks, and wherein if the signal from the slave unit to the first (master) communication device is no longer detected, the first communication device queries the second communication device on the wide are network to determine if the second communication device can detect the particular slave unit in question on its associated local area network, wherein the first communication device waits a timeout period for the second communication device to respond affirmatively and transfers master authority over the slave unit to the second communication device upon such affirmation.