Cordless or wireless system protocol for providing reliable channel connections

• US 6,112,098 A
• Filed: 11/26/1997
• Issued: 08/29/2000
• Est. Priority Date: 11/26/1997
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Yoshinaga, Hiroshi, Iwasaki, Tsutomu, Kwark, Young Hoon, Nakano, Nobutoyo, Flint, Eprhaim Bemis, Hamada, Hidenao, Gaucher, Brian Paul
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): Gesesse, Tilahun
• Application Number:
  US08/979,117
• Time in Patent Office: 1,007 Days
• Field of Search: 455/464, 455/450, 455/455, 455/434, 455/509, 455/511, 455/452, 455/513, 455/514, 455/515
• US Class Current: 455/464
• CPC Class Codes: H04M 1/72511 Searching for available channels
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 36/06 Reselecting a communication resource in the serving access point

Abstract

A method of channel selection between a remote and a base for a cordless or wireless communication system includes the steps of creating a history table having channels assigned to columns and intervals assigned to rows, scanning the channels to determine if interference exists, recording the channels having interference for a given interval in the history table and determining which channel has the least amount of interference over a predetermined number of intervals to select the best channel for communications.

Claims

1. A method of channel selection between a remote and a base for a cordless or wireless communication system comprising the steps of:

creating a history table having channels assigned to columns and time intervals assigned to rows;

scanning the channels to determine interference;

recording the channels having interference for a given time interval in the history table;

repeating the steps of scanning and recording for a predetermined number of time intervals;

analyzing each channel over said plurality of time intervals; and

determining which channel has a least amount of interference over said predetermined number of time intervals to select a best channel for communications.

2. The method as recited in claim 1 further comprises an RSSI and the step of scanning the channels includes outputting a voltage from the RSSI proportional to the interference for each channel.

3. The method as recited in claim 1 wherein the step of recording the channels having interference further comprises the step of measuring relative levels of interference for creating a weighting factor for determining the best channel for communications.

4. The method as recited in claim 1 wherein the step of creating a history table includes the steps of:

creating a first history table for the remote;

creating a second history table for the base; and

logically combining the first history table with the second history table.

5. The method as recited in claim 4 wherein the step of logically combining includes logically combining, by an OR gate, interference data in the rows and the columns of the first history table with interference data in the corresponding rows and columns of the second history table.

6. The method as recited in claim 1 wherein the step of determining which channel has the least amount of interference includes determining a backup channel having the least amount of interference of the remaining channels.

7. The method as recited in claim 1 further comprises the step of communicating between the remote and the base on the channel having the least amount of interference.

8. The method as recited in claim 7 further comprises the steps of:

periodically updating the history table to determine an updated channel having the least amount of interference; and

communicating between the remote and base on the updated channel.

9. The method as recited in claim 1 wherein the remote is a hand held device.

10. The method as recited in claim 1 wherein the base connects to a public switched telephone network (PSTN).

11. The method as recited in claim 1 wherein the remote is a modem.

12. The method as recited in claim 1 wherein the base is a computer and connects to a public switched telephone network (PSTN).

13. The method as recited in claim 1 wherein the history table has a predetermined number of channels for a predetermined number of intervals and includes the step of erasing interference data for the oldest interval to allow interference data for a new interval to be recorded in the history table.

14. A method of channel selection between a remote and a base for a cordless or wireless communication system comprising the steps of:

creating a first history table for the remote having channels assigned to columns and time intervals assigned to rows;

creating a second history table for the base having channels assigned to columns and time intervals assigned to rows;

scanning the channels to determine interference;

recording the channels having interference and relative levels of interference for each channel, for a given time interval, in the first history table and the second history table;

repeating the steps of scanning and recording for a predetermined number of time intervals for said first history and said second history table;

analyzing each channel over said plurality of time intervals;

logically combining the first history table with the second history table to create a combined history table; and

determining which channel has the least amount of interference over said predetermined number of time intervals to select the best channel for communications.

15. The method as recited in claim 14 wherein the step of recording the channels further comprises the step of creating a weighing factor based on the relative levels of interference to determine the best channel for communications.

16. The method as recited in claim 14 further comprises an RSSI and the step of scanning the channels includes outputting a voltage from the RSSI proportional to the interference for each channel.

17. The method as recited in claim 14 wherein the step of logically combining includes logically combining by an OR gate interference data in the rows and the columns of the first history table with interference data in the corresponding rows and columns of the second history table.

18. The method as recited in claim 14 wherein the step of determining which channel has the least amount of interference includes determining a backup channel having the least amount of interference of the remaining channels.

19. The method as recited in claim 14 further comprises the step of communicating between the remote and the base on the channel having the least amount of interference.

20. The method as recited in claim 14 further comprises the steps of:

periodically updating the combined history table to determine an updated channel having the least amount of interference; and

communicating between the remote and base on the updated channel.

21. The method as recited in claim 14 wherein the remote is a hand held device.

22. The method as recited in claim 14 wherein the base connects to a public switched telephone network (PSTN).

23. The method as recited in claim 14 wherein the remote is a modem.

24. The method as recited in claim 14 wherein the base is a computer and connects to a public switched telephone network (PSTN).

25. The method as recited in claim 14 wherein the combined history table has a predetermined number of channels for a predetermined number of intervals and includes the step of erasing interference data for the oldest interval to allow interference data for a new interval to be recorded in the combined history table.

26. A method of channel selection between a remote and a base station for a cordless or wireless communication system comprising the steps of:

creating a first history table for the remote having channels assigned to columns and time intervals assigned to rows;

creating a second history table for the base having channels assigned to columns and time intervals assigned to rows;

scanning the channels to determine interference;

outputting a voltage from the RSSI proportional to the interference for each channel;

recording the channels having interference and relative levels of interference for each channel, for a given time interval, in the first history table and the second history table;

repeating the steps of scanning and recording for a predetermined number of time intervals for said first history table and said second history table;

logically combining the first history table with the second history table to create a combined history table;

analyzing which channel has the least amount of interference over said predetermined number of time intervals to select the best channel for communications;

communicating between the remote and the base on the channel having the least amount of interference; and

determining a backup channel having the least amount of interference of the remaining channels.

27. The method as recited in claim 26 wherein the step of recording the channels further comprises the step of creating a weighing factor based on the relative levels of interference to determine the best channel for communications.

28. The method as recited in claim 26 wherein the step of logically combining includes logically combining by an OR gate interference data in the rows and the columns of the first history table with interference data in the corresponding rows and columns of the second history table.

29. The method as recited in claim 26 further comprises the steps of:

periodically updating the combined history table to determine an updated channel having the least amount of interference; and

communicating between the remote and base on the updated channel.

30. The method as recited in claim 26 wherein the remote is a hand held device.

31. The method as recited in claim 26 wherein the base connects to a public switched telephone network (PSTN).

32. The method as recited in claim 26 wherein the remote is a modem.

33. The method as recited in claim 26 wherein the base is a computer and connects to a public switched telephone network (PSTN).

34. The method as recited in claim 26 wherein the combined history table has a predetermined number of channels for a predetermined number of intervals and includes the step of erasing interference data for the oldest interval to allow interference data for a new interval to be recorded in the combined history table.