Point coordinated spread-spectrum wireless local area network

• US 6,980,810 B1
• Filed: 05/12/2003
• Issued: 12/27/2005
• Est. Priority Date: 05/12/2003
• Status: Expired due to Fees

• Current Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Sherman, Matthew J., Gerakoulis, Diakoumis Parissis, Miller, Robert Raymond II, Huang, Kenny Xiaojian
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): Doan, Kiet
• Application Number:
  US10/435,875
• Time in Patent Office: 960 Days
• Field of Search: 455/434, 455/517, 455/63, 455/442, 370/328, 370/466, 370/349, 342/386
• US Class Current: 455/450
• CPC Class Codes: H04W 16/10 Dynamic resource partitioning
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 92/02 Inter-networking arrangements
• CPC Class Codes: H04W 92/16 Interfaces between hierarchically similar devices

Abstract

Methods, devices and systems for WLAN communication are described. Intercell interference between overlapping WLAN cells is mitigated by a combination of frequency reuse, code division and time resource negotiation. Information used for time resource negotiation can be broadcast via beacon signal or communicated via a wireline backbone system which interconnects access points.

Claims

1. A method for wireless communication comprising the steps of:

assigning a communication channel to a wireless station, said communication channel having a frequency and a spreading code associated therewith;

determining whether said wireless station is located in a first area of a first cell which overlaps with another cell or in a second area of said first cell that is non-overlapping with respect to said another second cell; and

an access point of said first cell transmitting information to said wireless station during a first portion of a superframe when said wireless station is located in said first area and, during a second portion of said superframe when said wireless station is located in said second area where during said second portion of said superframe an access point of said another cell refrains from transmitting,

transmitting a beacon signal containing information associated with a duration of said first and second portions of said superframe;

receiving a beacon signal from said another cell and using information in said beacon signal to determine said duration of said first and second portions of said superframe.

2. The method of claim 1, wherein said wireless station is a WLAN station operating in the 2.4 GHz band.

3. The method of claim 2, wherein said frequency is one of three non-overlapping frequencies in said 2.4 GHz band.

25. The method of claim 1, wherein said wireless station is a WLAN station operating outside the 2.4 GHz band.

4. A method for communicating overlap management information in a wireless communication system having at least first, second and third cells, comprising the steps of:

transmitting, from said first cell, a first beacon signal indicating a first time period during which said first cell will transmit to wireless stations in an area which is overlapping with said second cell;

transmitting, from said second cell, a second beacon signal indicating a second time period during which said second cell will transmit to wireless stations in an area which is overlapping with one of said first cell and said third cell; and

transmitting, from said third cell, a third beacon signal indicating a third time period during which said third cell will transmit to wireless stations in an area which is overlapping with said second cell.

5. The method of claim 4, wherein said first step of transmitting further comprises the step of:

transmitting a total amount of time that said first cell requires per superframe to transmit information to wireless stations in areas which overlap with at least one of said second cell and said third cell.

6. The method of claim 4, wherein said second step of transmitting further comprises the step of:

transmitting a total amount of time that said second cell requires per superframe to transmit information to wireless stations in areas which overlap with at least one of said first cell and said third cell.

7. The method of claim 4, wherein said third step of transmitting further comprises the step of:

transmitting a total amount of time that said third cell requires per superframe to transmit information to wireless stations in areas which overlap with at least one of said first cell and said second cell.

8. The method of claim 4, wherein said first step of transmitting further comprises the step of:

transmitting an amount of time that said first cell requires per superframe to transmit information to wireless stations in areas which are non-overlapping with either of said second cell and said third cell.

9. The method of claim 4, wherein said second step of transmitting further comprises the step of:

transmitting an amount of time that said second cell requires per superframe to transmit information to wireless stations in areas which are non-overlapping with either of said first cell and said third cell.

10. The method of claim 4, wherein said third step of transmitting further comprises the step of:

transmitting an amount of time that said third cell requires per superframe to transmit information to wireless stations in areas which are non-overlapping with either of said first cell and said second cell.

11. The method of claim 4, wherein said first second and third beacon signals are transmitted outside of a bandwidth used to communicate with said wireless stations.

12. An access point for use in a wireless local area network, said access point comprising:

a processor for assigning a communication channel to a wireless station, said communication channel having a frequency and a spreading code associated therewith;

said processor also for determining whether said wireless station is located in a first area which overlaps with another cell or in a second area which is non-overlapping with respect to said another cell; and

a transmitter for transmitting information to said wireless station during a first portion of a superframe if said wireless station is located in said first area and, alternatively, during a second portion of said superframe if said wireless station is located in said second area, transmitter also transmits a beacon signal containing information associated with a duration of said first and second portions of said superframe;

a receiver for receiving a beacon signal from said other cell and using, in said processor, information in said beacon signal to determine said duration of said first and second portions of said superframe.

13. The access point of claim 12, wherein said wireless station is a WLAN station operating in the 2.4 GHz band.

14. The access point of claim 13, wherein said frequency is one of three non-overlapping frequencies in said 2.4 GHz band.

15. The access point of claim 12, further comprising:

means for preventing transmissions during a third portion of said superframe.

26. The access point of claim 12, wherein said wireless station is a WLAN station operating outside the 2.4 GHz band.

16. An access point disposed in a first cell for communicating overlap management information in a wireless communication system having at least first, second and third cells, comprising:

a transmitter for transmitting, from said first cell, a first beacon signal indicating a first time period during which said access point will transmit to wireless stations in an area which is overlapping with said second cell; and

a receiver, for receiving from said second cell, a second beacon signal indicating a second time period during which said second cell will transmit to wireless stations in an area which is overlapping with one of said first cell and said third cell;

wherein said receiver also receives, from said third cell, a third beacon signal indicating a third time period during which said third cell will transmit to wireless stations in an area which is overlapping with said second cell.

17. The access point of claim 16, wherein said transmitter also transmits a total amount of time that said first cell requires per superframe to transmit information to wireless stations in areas which overlap with at least one of said second cell and said third cell.

18. The access point of claim 16, wherein said receiver also receives a total amount of time that said second cell requires per superframe to transmit information to wireless stations in areas which overlap with at least one of said first cell and said third cell.

19. The access point of claim 16, wherein said receiver also receives a total amount of time that said third cell requires per superframe to transmit information to wireless stations in areas which overlap with at least one of said first cell and said second cell.

20. The access point of claim 16, wherein said transmitter also transmits an amount of time that said first cell requires per superframe to transmit information to wireless stations in areas which are non-overlapping with either of said second cell and said third cell.

21. The access point of claim 16, wherein said receiver also receives an amount of time that said second cell requires per superframe to transmit information to wireless stations in areas which are non-overlapping with either of said first cell and said third cell.

22. The access point of claim 16, wherein said receiver also receives an amount of time that said third cell requires per superframe to transmit information to wireless stations in area which are non-overlapping with either of said first cell and said second cell.

23. The access point of claim 16, wherein said first, second and third beacon signals are transmitted over an air interface outside of a bandwidth used to communicate with said wireless stations.

24. The access point of claim 16, wherein proxy signals are transmitted and received via a wireline backbone network.