Synchronization of a Plurality of Devices in a Wireless Sensor Arrangement

• US 20100265937A1
• Filed: 06/29/2010
• Published: 10/21/2010
• Est. Priority Date: 02/27/2006
• Status: Active Grant

• Current Assignee: Cool River Systems, LLC
• Original Assignee: Frederick E. Frantz
• Inventors: Frantz, Frederick E.
• Granted Patent: US 8,085,623 B2
• Time in Patent Office: Days
• US Class Current: 370/350
• CPC Class Codes: H04W 56/0085 detecting a given structure in the signal
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

Two or more wirelessly networked devices for control or data acquisition functions for real-time application are provided with a error corrected synchronization and data collection process. A single start device transmits a start message, followed by each stop device acknowledging that start message. If one or more stop devices fails to acknowledge the initial start message, one or more start messages are transmitted including an elapsed time since the initial start message. Each stop device receives the initial start message and any subsequent start messages, using the elapsed time in the start message to synchronize a local timer. Upon stop event detection, each stop device records its local timer value and subsequently transmits that value to a collection device or console.

Claims

1. A computer readable storage memory device comprising:

a computer readable storage memory device suitable for encoding of computer executable programs, the computer readable storage memory device being selected from a group consisting of a computer hard drive, a floppy disk, a compact disk, a digital versatile disk, a circuit-based memory device, and a memory module; and

one or more computer executable programs encoded by the computer readable storage memory device configured to cause a processor to;

by a start device in an area of a multi-contestant competitive swimming event;

establish a single authoritative start time upon activation by a starting official, run a cycle timer beginning at the single authoritative start time, and

attempt to synchronize and resynchronize a plurality of stop devices by wirelessly broadcasting within an area of a swimming pool a plurality of start messages;

by a plurality of stop devices within the area of the competitive swimming event, each of the contestants being assigned to a swim lane wherein two or more stop devices are assigned to each swim lane, each stop device being operated by a stop official;

synchronize or resynchronize a local stop timer to the single authoritative start time from at least one of the start messages; and

wirelessly transmit a stop message responsive to activation of a stop trigger by a stop official subsequent to the initialization, each stop message having a stop time parameter equal to a current value of a local stop timer upon stop trigger operation; and

by a control device within the area of the competitive swimming event, responsive to receiving the stop messages, produce a recording of one or more stop time parameters;

wherein all of the recorded stop time parameters are synchronized or resynchronized to the single authoritative start time.

2. The computer readable storage memory device as set forth in claim 1 wherein the computer executable program is further configured to:

by a control device, broadcast a missed-acknowledgment message upon failure to receive an acknowledgment from all of the stop devices within a maximum delay from receiving the start message; and

by the start device responsive to a missed-acknowledgment message, broadcast an updated start message containing a current value of the cycle timer.

3. The computer readable storage memory device as set forth in claim 2 wherein the program resynchronizes by broadcasting by the start device an updated start message containing an elapsed time value since the single authoritative start time a periodic basis.

4. The computer readable storage memory device as set forth in claim 2 wherein the program resynchronizes by broadcasting by the start device an updated start message containing an elapsed time value since the single authoritative start time on a randomly-timed basis.

5. The computer readable storage memory device as set forth in claim 1 wherein the program further compensates for a message transmission delay.