RF channel linking method and system

• US 7,248,836 B2
• Filed: 09/30/2002
• Issued: 07/24/2007
• Est. Priority Date: 09/30/2001
• Status: Active Grant

• Current Assignee: Ingersoll-Rand Nexia Intelligence, LLC (Trane Technologies plc)
• Original Assignee: Schlage Lock Company (Allegion PLC)
• Inventors: Taylor, Ronald
• Primary Examiner(s): Cumming; William D.
• Application Number:
  US10/261,933
• Publication Number:
  US 20030143956A1
• Time in Patent Office: 1,758 Days
• Field of Search: 455/67.1, 455/522
• US Class Current: 455/67.11
• CPC Class Codes: G07C 2009/00793 by Hertzian waves
• CPC Class Codes: G07C 9/27 with central registration
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment

Abstract

In an RF access control system, a method for establishing a reliable RF signal link between points of the RF access control system. A first RF signal from a first point of the system is transmitted to a second point of the system at a first RF power level that is below a second RF power level used during normal operation of the RF access control system. Once the second point acknowledges the RF signal from the first point, then a pre-determined number of RF packets are transmitted and received back and forth between the first point and the second point at the first RF power level. An RF packet error count is generated in response to the transmitting and receiving of the pre-determined number of RF packets. If this error count is below a certain threshold value, then an indication is provided to an installer of the RF access control system of an RF channel number to be used by the RF access control system during normal operation.

Claims

1. In an RF access control system, a method for establishing a communication link on an RF channel between a first transceiver and a second transceiver of said RF access control system, said method comprising:

transmitting an RF signal on a first RF channel from a first transceiver to a second transceiver at a first RF power level that is below a second RF power level, wherein said second RF power level is used during normal operation of said RF access control system;

receiving a pre-determined number of bits at said second transceiver;

generating an error count corresponding to the number of errors received in said pre-determined number of bits;

comparing said error count to a pre-determined error threshold; and

determining said RF channel to be a valid communication link when said error count is less than said predetermined threshold.

2. The method of claim 1 further including the step of transmitting an RF signal on said first RF channel from said second transceiver to said first transceiver at said first RF power level.

3. The method of claim 2 further including the steps of:

receiving a pre-determined number of bits at said first transceiver;

generating a second error count corresponding to the number of errors received in said pre-determined number of bits; and

comparing said second error count to a second pre-determined error threshold.

4. The method of claim 3 further including the step of combining said error count and said second error count to determine whether said RF channel is a valid communication link.

5. The method of claim 1 further including the step of providing an indication of the establishment of a valid communication link at at least one of said first transceiver and said second transceiver.

6. The method of claim 1 wherein said first RF channel is one of a plurality of RF channels, said method further including the step of:

determining said RF channel to be an invalid communication link when said error count is greater than said predetermined threshold; and

switching to a second RF channel different from said first RF; and

performing the transmitting, receiving, generating, comparing and determining steps to determine if said second RF channel is a valid communication link.

7. The method of claim 6 further including the step of providing an indication of the establishment of a valid communication link wherein said indication includes identifying the RF channel forming the valid communication link.

8. The method of claim 6 wherein said method may check each of the available RF channels to attempt to establish a valid communication link.

9. The method of claim 8 wherein each available RF channel is checked a plurality of times.

10. The method of claim 8 wherein at least one of said first transceiver and said second transceiver no longer receive signals after a predetermined amount of time has elapsed.

11. An access control system having a wireless communication link, said system including:

a first transceiver transmitting a wireless signal composed of a predetermined number of bits on a first channel to said second receiver, wherein said wireless signal is transmitted at a power level less then power level employed during regular data communication;

a second transceiver receiving said wireless signal and generating an error count corresponding to the number of erroneous bits received in said wireless signal;

a processor communicating with said second transceiver and comparing said error count to a pre-determined error threshold, said processor determining said channel to be a valid communication link when said error count is less than said predetermined threshold.

12. The system of claim 11 wherein said second transceiver transmits a second wireless signal composed of a predetermined number of bits on said first channel to said first receiver, wherein said wireless signal is transmitted at a power level less then power level employed during regular data communication.

13. The system of claim 12 wherein said first transceiver receives said second wireless signal and generates an second error count corresponding to the number of erroneous bits received in said second wireless signal.

14. The system of claim 13 wherein said processor also communicates with said first transceiver and combines said error count and said second error count to determine whether said RF channel is a valid communication link.

15. The system of claim 11 wherein at least one of said first transceiver and said second transceiver includes an indicator for providing an indication of the establishment of a valid communication link.

16. The system of claim 11 wherein said first wireless channel is one of a plurality of wireless channels and said when said first wireless channel is determined not to be a valid communication link, said first transceiver transmits to said second transceiver on a second wireless channel different from said first wireless channel.

17. The system of claim 16 wherein at least one of said first transceiver and said second transceiver includes an indicator for providing an indication of the establishment of a valid communication link, and wherein said indicator also identifies the wireless channel forming the valid communication link.

18. The system of claim 16 wherein said first transceiver transmits to said second transceiver over each of said plurality of wireless channels to attempt to establish a valid communication link.

19. The system of claim 18 wherein said first transceiver transmits to said second transceiver over each of said plurality of wireless channels a plurality of times.

20. The system of claim 18 wherein at least one of said first transceiver and said second transceiver no longer receive signals after a predetermined amount of time has elapsed.