Methods and systems for aligning and maintaining alignment of point-to-point transceivers in a network

• US 20040208272A1
• Filed: 06/03/2002
• Published: 10/21/2004
• Est. Priority Date: 06/03/2002
• Status: Active Grant

• Current Assignee: Clearmesh Networks Incorporated
• Original Assignee: Clearmesh Networks Incorporated
• Inventors: Moursund, Carter M., Ulmer, Christopher T.
• Granted Patent: US 7,236,705 B2
• Time in Patent Office: Days
• US Class Current: 375/356
• CPC Class Codes: H04B 10/1123 Bidirectional transmission

Abstract

A digital data network uses network nodes incorporating infrared transceivers. Each node includes a plurality of infrared transceivers having transmitter and receiver optics designed to facilitate line-of-sight infrared optical communications in a residential or business neighborhood. New nodes are installed with at least one selected transceiver having line-of-sight access to at least one existing transceiver. Automated tracking and acquisition processes are used to align transceivers to enable data communication and to acquire newly installed nodes into the network.

Other automated tracking programs operate on an as-needed or scheduled basis to maintain good alignment and communications between adjoining node transceivers.

Network nodes include weather-proof housings and are of a size and shape to be easily mounted on existing structures so as not to disrupt the visual appeal of a neighborhood.

Claims

1. A method of installing a new point-to-point communications transceiver in a network of existing point-to-point communications transceivers, comprising the steps of:

positioning a new transceiver in a line of sight to at least one existing transceiver;

positioning said new transceiver to point in a predetermined compass direction;

at a predetermined time, said new transceiver performing a first sweep over a first predetermined range to detect a signal from said existing transceiver;

at said predetermined time synchronously with said new transceiver, said existing transceiver performing a second sweep over a second predetermined range to detect a signal from said new transceiver;

upon the completion of said first sweep of said new transceiver, said new transceiver returning to a position of maximum detected signal strength; and

upon the completion of said second sweep of said existing transceiver, said existing transceiver returning to a position of maximum detected signal strength.

2. The method of claim 1 wherein said first and second sweeps are performed with said new and existing transceivers each level to ground;

and

if no signal strength is detected by either of said new or existing transceivers, then changing the elevation of said new and existing transceivers and repeating said first and second sweeps to determine if a signal is detected.

3. The method of claim 2 wherein said step of changing the elevation of said new and existing transceivers includes changing the elevation of said new transceiver in an orientation complementary to said existing transceiver.

4. The method of claim 3 wherein said step of changing the elevation of said new and existing transceivers is repeated in half-predicted-beam-width increments while repeating said first and second sweeps to determine if a signal is detected.

5. The method of claim 4 wherein if no signal is detected an error is reported and a second existing transceiver is selected to install said new transceiver.

6. The method of claim 1 and further including the steps of:

storing, during said first sweep of said new transceiver, a detected signal strength; and

storing, during said second sweep of said existing transceiver, a detected signal strength.

7. The method of claim 1 and further including the steps of:

after said new transceiver returns to a position of maximum detected signal strength, with said existing transceiver stationary, tracking said new transceiver over a first predetermined path to determine a new position of maximum signal strength in said first predetermined path; and

after the completion of said tracking of said new transceiver, returning said new transceiver to said new position of maximum signal strength in said first predetermined path.

8. The method of claim 7 and further including the steps of:

after said existing transceiver returns to a position of maximum detected signal strength, with said new transceiver stationary, tracking said existing transceiver over a second predetermined path to determine a new position of maximum signal strength in said second predetermined path; and

after the completion of said tracking of said existing transceiver, returning said new transceiver to said new position of maximum signal strength in said second predetermined tracking path.

9. The method of claim 8 wherein said first and second sweeps are each generally circular sweeps.

10. The method of claim 9 wherein said first and second predetermined tracking paths each comprises a dither path.

11. The method of claim 8 and further including the steps of:

monitoring the detected signal strength of said new transceiver;

monitoring the detected signal strength of said existing transceiver;

if said detected signal strength of said new or said existing transceiver falls below a predetermined threshold, then repeating each of said tracking of said new transceiver in said first predetermine tracking path and said tracking of said existing transceiver in said second predetermined path to return each of said new and existing transceivers to new positions of maximum signal strength.

12. The method of claim 11 wherein said step of repeating each of said tracking of said new transceiver and said existing transceiver is initiated at a first time preprogrammed for said new transceiver and a second time preprogrammed for said existing transceiver.

13. The method of claim 1 wherein said new and existing transceiver each comprise an infrared transceiver.

14. The method of claim 1 wherein said new transceiver is mounted in a housing, said step of positioning said new transceiver to point in a predetermined compass direction including positioning said housing to point in a selected compass direction.

15. A system for installing a new point-to-point communications transceiver in a network of existing point-to-point communications transceivers, the system comprising:

means for positioning a new transceiver in a line of sight to at least one existing transceiver;

means for positioning said new transceiver to point in a predetermined compass direction;

means operative at a predetermined time, for initiating said new transceiver to perform a first sweep over a first predetermined range to detect a signal from said existing transceiver;

means operative at said predetermined time, for initiating said existing transceiver performing a second sweep over a second predetermined range to detect a signal from said new transceiver;

means operative upon the completion of said first sweep of said new transceiver, for initiating said new transceiver to return to a position of maximum detected signal strength; and

means operative upon the completion of said second sweep of said existing transceiver, for initiating said existing transceiver to return to a position of maximum detected signal strength.

16. A system for installing a new point-to-point communications transceiver in a network of existing point-to-point communications transceivers, comprising:

a processor;

a memory connected to said processor;

said memory operative with control instructions stored in said processor to cause said processor to perform the steps of positioning a new transceiver in a line of sight to at least one existing transceiver;

positioning said new transceiver to point in a predetermined compass direction;

at a predetermined time, said new transceiver performing a first sweep over a first predetermined range to detect a signal from said existing transceiver;

at said predetermined time synchronously with said new transceiver, said existing transceiver performing a second sweep over a second predetermined range to detect a signal from said new transceiver;

upon the completion of said first sweep of said new transceiver, said new transceiver returning to a position of maximum detected signal strength; and

upon the completion of said second sweep of said existing transceiver, said existing transceiver returning to a position of maximum detected signal strength.

17. A method of maintaining the alignment of first and second communicating transceivers in a network of existing point-to-point communications transceivers, comprising the steps of:

monitoring the signal strength received by said first transceiver;

monitoring the signal strength received by said second transceiver;

if either of the signal strength received by said first transceiver or the signal strength received by said second transceiver falls below a predetermined threshold, then

with said second transceiver stationary, tracking said first transceiver over a first predetermined path to determine a position of maximum signal strength detected by said first transceiver in said first predetermined path,

after the completion of said tracking of said first transceiver, returning said first transceiver to said position of maximum signal strength detected by said first transceiver in said first predetermined path,

with said first transceiver stationary, tracking said second transceiver over a second predetermined path to determine a position of maximum signal strength detected by said second transceiver in said second predetermined path, and

after the completion of said tracking of said second transceiver, returning said second transceiver to said position of maximum signal strength detected by said second transceiver in said second predetermined tracking path.

18. A method in accordance with claim 17 wherein:

said step of tracking said first transceiver over a first predetermined path is performed at a first predetermined time; and

said step of tracking said second transceiver over a second predetermined path is performed at a second predetermined time.

19. A method in accordance with claim 18 wherein:

said first predetermined time is stored in a memory contained in said first transceiver;

said second predetermined time is stored in a memory contained in said second transceiver; and

said first predetermined time is different from said second predetermined time.

20. A method in accordance with claim 17 wherein each of said first and second predetermined paths is a dither path.

21. A method in accordance with claim 17 wherein each of said first and second transceivers is an infrared transceiver.

22. A system maintaining the alignment of first and second communicating transceivers in a network of existing point-to-point communications transceivers, comprising:

a first detector for monitoring the signal strength received by said first transceiver;

a second detector for monitoring the signal strength received by said second transceiver;

a processor connected to each of said first and second detectors;

a memory connected to said processor and storing control instructions;

said processor responsive to said first and second detectors and operative with the control instructions in said memory to perform the steps of

if either of the signal strength received by said first transceiver or the signal strength received by said second transceiver falls below a predetermined threshold, then

with said second transceiver stationary, tracking said first transceiver over a first predetermined path to determine a position of maximum signal strength detected by said first transceiver in said first predetermined path,

after the completion of said tracking of said first transceiver, returning said first transceiver to said position of maximum signal strength detected by said first transceiver in said first predetermined path,

with said first transceiver stationary, tracking said second transceiver over a second predetermined path to determine a position of maximum signal strength detected by said second transceiver in said second predetermined path, and

after the completion of said tracking of said second transceiver, returning said second transceiver to said position of maximum signal strength detected by said second transceiver in said second predetermined tracking path.

23. A system for maintaining the alignment of first and second communicating transceivers in a network of existing point-to-point communications transceivers, comprising:

means for monitoring the signal strength received by said first transceiver;

means for monitoring the signal strength received by said second transceiver;

means operative, if either of the signal strength received by said first transceiver or the signal strength received by said second transceiver falls below a predetermined threshold, for

with said second transceiver stationary, tracking said first transceiver over a first predetermined path to determine a position of maximum signal strength detected by said first transceiver in said first predetermined path,

after the completion of said tracking of said first transceiver, returning said first transceiver to said position of maximum signal strength detected by said first transceiver in said first predetermined path,

with said first transceiver stationary, tracking said second transceiver over a second predetermined path to determine a position of maximum signal strength detected by said second transceiver in said second predetermined path, and

after the completion of said tracking of said second transceiver, returning said second transceiver to said position of maximum signal strength detected by said second transceiver in said second predetermined tracking path.