Interference resistant wireless sensor and control system

• US 20030224729A1
• Filed: 05/28/2002
• Published: 12/04/2003
• Est. Priority Date: 05/28/2002
• Status: Active Grant

• Current Assignee: Wireless Innovation Incorporated
• Original Assignee: Hitech Equipment Corporation
• Inventors: Arnold, Kenneth David
• Granted Patent: US 6,990,317 B2
• Time in Patent Office: Days
• US Class Current: 455/59
• CPC Class Codes: G08C 17/02 using a radio link
• CPC Class Codes: G08C 2201/63 Redundant transmissions
• CPC Class Codes: H04B 7/0837 using pre-detection combining H04B7/0868 takes precedence
• CPC Class Codes: H04B 7/12 Frequency diversity

Abstract

A wireless sensor and control system includes wireless RF transmitter units and one or more receivers that communicate using more than one narrowband radio channel to provide increased reliability in the presence of unintentional radio interference. The output of a sensor transducer or closure of a switch contact can trigger transmissions at two or more narrowband carrier frequencies that are subsequently decoded by the receiver(s). The remote sensor data can then be passed to another system for processing and/or utilized to control remote devices. In accordance with one practical embodiment, the remote sensor data indicates the ingress or egress of monitored product inventory.

Claims

1. A wireless data transmission method comprising:

transmitting a first data packet containing remote sensor data using a first carrier frequency; and

transmitting a second data packet containing remote sensor data using a second carrier frequency, wherein the content of said second data packet is identical to the content of said first data packet.

2. A method according to claim 1, wherein transmitting said first data packet and transmitting said second data packet are performed sequentially.

3. A method according to claim 1, wherein transmitting said first data packet and transmitting said second data packet are performed such that at least a portion of said first data packet and at least a portion of said second data packet are transmitted concurrently.

4. A method according to claim 3, wherein transmitting said first data packet and transmitting said second data packet are performed simultaneously.

5. A method according to claim 1, wherein said first carrier frequency is 315 MHz and said second carrier frequency is 433 MHz.

6. A method according to claim 1, further comprising:

retransmitting said first data packet using said first carrier frequency; and

retransmitting said second data packet using said second carrier frequency.

7. A method according to claim 6, wherein said step of retransmitting said first data packet is performed before said step of transmitting said second data packet.

8. A method according to claim 6, wherein retransmitting said first data packet and retransmitting said second data packet are performed simultaneously.

9. A method according to claim 1, further comprising:

detecting an event occurrence;

obtaining said remote sensor data in response to said event occurrence; and

inserting said remote sensor data into said first data packet.

10. A method according to claim 9, wherein said first data packet further comprises:

a unique transmitter unit identifier;

a current sequence number; and

historical remote sensor data obtained before obtaining said remote sensor data.

11. A method according to claim 10, wherein said historical remote sensor data represents remote sensor data corresponding to at least one previously detected event occurrence.

12. A wireless data transmission method comprising:

detecting an event occurrence;

obtaining remote sensor data in response to said event occurrence;

creating a data packet containing said remote sensor data; and

transmitting identical copies of said data packet using a plurality of different carrier frequencies.

13. A wireless data transmission method according to claim 12, wherein said transmitting step comprises:

transmitting a first identical copy of said data packet using a first carrier frequency of 315 MHz; and

transmitting a second identical copy of said data packet using a second carrier frequency of 433 MHz.

14. A wireless data transmission method according to claim 12, wherein said transmitting step transmits identical copies of said data packet using less than ten different carrier frequencies.

15. A wireless data transmitter unit comprising:

a controller configured to obtain remote sensor data generated in response to an event occurrence, and to create data packets containing said remote sensor data; and

a transmitter arrangement coupled to said controller and configured to transmit at least a first data packet containing said remote sensor data using a first carrier frequency, and a second data packet containing said remote sensor data using a second carrier frequency, wherein the content of said second data packet is identical to the content of said first data packet.

16. A wireless data transmitter unit according to claim 15, wherein said transmitter arrangement is configured to transmit said first data packet and said second data packet sequentially.

17. A wireless data transmitter unit according to claim 15, wherein said transmitter arrangement is configured to transmit said first data packet and said second data packet such that at least a portion of said first data packet and at least a portion of said second data packet are transmitted concurrently.

18. A wireless data transmitter unit according to claim 17, wherein said transmitter arrangement is configured to transmit said first data packet and said second data packet simultaneously.

19. A wireless data transmitter unit according to claim 15, wherein said transmitter arrangement comprises at least a first transmitter configured to transmit data packets at said first carrier frequency, and a second transmitter configured to transmit data packets at said second carrier frequency.

20. A wireless data transmitter unit according to claim 15, wherein said first carrier frequency is 315 MHz and said second carrier frequency is 433 MHz.

21. A wireless data transmitter unit according to claim 15, wherein said transmitter arrangement is further configured to retransmit said first data packet using said first carrier frequency, and to retransmit said second data packet using said second carrier frequency.

22. A wireless data transmitter unit according to claim 15, further comprising a number of sensors coupled to said controller and configured to detect said event occurrence.

23. A wireless data transmitter unit according to claim 22, wherein said number of sensors comprises a plurality of switches.

24. A wireless data transmitter unit according to claim 15, further comprising an antenna structure coupled to said transmitter arrangement.

25. A wireless data transmitter unit according to claim 15, fuither comprising an integral power supply that provides operating power to at least said controller and said transmitter arrangement.

26. A wireless data transmitter unit according to claim 15, wherein said controller is configured to create data packets containing at least said remote sensor data, a unique transmitter unit identifier, a current sequence number, and historical remote sensor data obtained before obtaining said remote sensor data.

27. A wireless data transmitter unit according to claim 26, wherein said historical remote sensor data represents remote sensor data corresponding to at least one previously detected event occurrence.

28. A wireless data reception method comprising:

receiving, on a first carrier frequency, a first data packet containing remote sensor data; and

receiving, on a second carrier frequency, a second data packet containing remote sensor data, wherein the content of said second data packet is identical to the content of said first data packet.

29. A method according to claim 28, wherein receiving said first data packet and receiving said second data packet are performed sequentially.

30. A method according to claim 28, wherein receiving said first data packet and receiving said second data packet are performed such that at least a portion of said first data packet and at least a portion of said second data packet are received concurrently.

31. A method according to claim 30, wherein receiving said first data packet and receiving said second data packet are performed simultaneously.

32. A method according to claim 28, wherein said first carrier frequency is 315 MHz and said second carrier frequency is 433 MHz.

33. A method according to claim 28, wherein said first data packet contains at least said remote sensor data, a unique transmitter unit identifier, a current sequence number, and historical remote sensor data.

34. A method according to claim 33, further comprising processing said current sequence number to determine whether a previously transmitted data packet was received.

35. A method according to claim 34, further comprising processing said historical remote sensor data to recover remote sensor data corresponding to a previously transmitted data packet.

36. A method according to claim 28, further comprising discarding said first data packet or said second data packet.

37. A wireless data receiving arrangement comprising:

a first receiver element configured to receive, on a first carrier frequency, a first data packet containing remote sensor data; and

a second receiver element configured to receive, on a second carrier frequency, a second data packet containing remote sensor data, wherein the content of said second data packet is identical to the content of said first data packet.

38. A wireless data receiving arrangement according to claim 37, wherein said first receiver element and said second receiver element are configured to respectively receive said first data packet and said second data packet sequentially.

39. A wireless data receiving arrangement according to claim 38, wherein said first receiver element and said second receiver element are configured to respectively receive at least a portion of said first data packet and at least a portion of said second data packet concurrently.

40. A wireless data receiving arrangement according to claim 39, wherein said first receiver element and said second receiver element are configured to receive said first data packet and said second data packet simultaneously.

41. A wireless data receiving arrangement according to claim 37, wherein said first data packet and said second data packet each contains at least said remote sensor data, a unique transmitter unit identifier, a current sequence number, and historical remote sensor data.

42. A wireless data receiving arrangement according to claim 37, further comprising a controller configured to process said current sequence number to determine whether a previously transmitted data packet was received.

43. A wireless data receiving arrangement according to claim 42, wherein said controller is further configured to process said historical remote sensor data to recover remote sensor data corresponding to a previously transmitted data packet.

44. A wireless data receiving arrangement according to claim 37, wherein said first receiver element and said second receiver element are co-located.

45. A wireless data receiving arrangement according to claim 37, wherein said first receiver element and said second receiver element are physically separated.

46. A wireless sensor data communication system comprising:

a plurality of wireless data transmitter units, each comprising;

a controller configured to obtain remote sensor data generated in response to an event occurrence, and to create data packets containing said remote sensor data; and

a transmitter arrangement coupled to said controller and configured to transmit at least a first data packet containing said remote sensor data using a first carrier frequency, and a second data packet containing said remote sensor data using a second carrier frequency, wherein the content of said second data packet is identical to the content of said first data packet; and

a wireless data receiving arrangement comprising a first receiver element configured to receive said first data packet on said first carrier frequency, and a second receiver element configured to receive said second data packet on said second carrier frequency.

47. A system according to claim 46, further comprising a data processing unit coupled to said wireless data receiving arrangement, said data processing unit being configured to receive data indicative of said remote sensor data from said wireless data receiving arrangement.

48. A system according to claim 46, wherein said data processing unit is configured to receive at least one of said first data packet and said second data packet from said wireless data receiving arrangement.

49. A wireless sensor data communication method comprising:

detecting a plurality of event occurrences;

for each of said event occurrences;

obtaining remote sensor data;

creating a data packet containing said remote sensor data;

transmitting, from a first component, identical copies of said data packet using a plurality of different carrier frequencies;

receiving, at a second component, said identical copies of said data packet on said plurality of different carrier frequencies; and

processing said remote sensor data from at least one of said identical copies of said data packet.

50. A wireless sensor data communication method according to claim 49, wherein each of said event occurrences represents an inventory change for a monitored item.

51. A wireless sensor data communication method according to claim 50, wherein said remote sensor data comprises data representing an addition of inventory and data representing a removal of inventory.

52. A wireless sensor data communication method according to claim 49, wherein said processing step is performed by an inventory control application.