System and method for controlling antenna downtilt/uptilt in a wireless communication network

• US 6,549,529 B1
• Filed: 02/01/1999
• Issued: 04/15/2003
• Est. Priority Date: 02/01/1999
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Polakos, Paul, Rajkumar, Ajay, Triolo, Anthony, Ziesse, Norman, Drabeck, Lawrence, Hampel, Karl, Mankiewich, Paul
• Primary Examiner(s): Yao, Kwang Bin
• Assistant Examiner(s): JONES, PRENELL P
• Application Number:
  US09/240,577
• Time in Patent Office: 1,534 Days
• Field of Search: 370/347, 370/252, 370/338, 370/401, 370/328, 370/489, 455/442, 455/422, 455/436, 455/522, 455/562, 455/561, 455/226.2, 455/524, 455/575, 455/63, 455/447, 455/446, 455/423, 342/367, 342/372, 343/853, 714/26
• US Class Current: 370/347
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence
• CPC Class Codes: H04W 16/28 using beam steering

Abstract

The wireless communication system includes antennas having electrically controllable downtilt angles and downtilt controllers associated with each antenna. The downtilt controllers receive instructions from a main controller, and adjust the downtilt angles of the associated antennas in accordance with the received instructions.

Claims

1. A wireless communication system, comprising:

a plurality of cell sites, each cell site including an antenna having an electrically controllable downtilt angle and an associated downtilt controller controlling a downtilt angle of said associated antenna; and

a main controller outputting a control signal to said downtilt controllers of at least two cell sites to adjust said downtilt angle of said associated antennas of said at least two cell sites and the relationship therebetween,

wherein said main controller generates and outputs said main control signals based on at least one operational measurement of said wireless communication system.

2. The system of claim 1, wherein said operational measurement is at least one of load, signal strength of signals received from two of said antennas, interference between signals received from said first and second antennas, a signal-to-noise ratio of signals received from one of said antennas, and a bit error rate of signals received from one of said antennas.

3. The system of claim 1, wherein said main controller outputs control signals to said at least two downtilt controllers to simultaneously adjust said downtilt angles of said associated antennas.

4. The system of claim 1, wherein said control signal indicates at least one of desired downtilt angles for said associated antennas and desired changes in said downtilt angles for said associated antennas.

5. A wireless communication system, comprising:

a primary cell site including a primary antenna having an electrically controllable downtilt angle and a primary downtilt controller controlling said downtilt angle of said primary antenna, said primary antenna having a primary coverage area based on said downtilt angle thereof;

at least one secondary cell site including a secondary antenna having an electrically controllable downtilt angle and a secondary downtilt controller controlling said downtilt angle of said secondary antenna, said secondary antenna having a secondary coverage area based on said downtilt angle thereof, said secondary coverage area being adjacent to said primary coverage area; and

a main controller determining whether said primary coverage area is overloaded, and outputting control signals to said primary and secondary downtilt controllers to adjust a boundary between said primary and secondary coverage areas by respectively changing said downtilt angles of said primary and secondary antennas when said primary coverage area is overloaded.

6. The system of claim 5, wherein said main controller determines said primary coverage area is overloaded by monitoring a primary load on said primary coverage area, and determining when said primary load exceeds a first predetermined threshold.

7. The system of claim 5, wherein said main controller monitors secondary load on said secondary coverage area, and outputs said control signals based on said secondary load on said secondary coverage area when said primary coverage area is overloaded.

8. The system of claim 7, wherein said main controller determines whether said secondary coverage area is available to handle additional load based on said secondary load, and outputs said control signals to adjust said boundary between said secondary coverage area and said primary coverage area when said primary coverage area is overloaded and said secondary coverage area is available.

9. The system of claim 8, wherein said main controller determines said secondary coverage area is available when said secondary load is less than a second predetermined threshold.

10. The system of claim 5, wherein said main controller outputs control signals to said primary downtilt controller to increase said downtilt angle of said primary antenna when said primary coverage area is overloaded.

11. The system of claim 10, wherein said main controller outputs control signals to said secondary downtilt controller to decrease said downtilt angle of said second antenna when said primary coverage area is overloaded.

12. A method of controlling antenna tilt in a controller of a wireless communication system, comprising:

providing a plurality of cell sites, each cell site including an antenna, each antenna having an electrically controllable downtilt angle and an associated downtilt controller controlling a downtilt angle of said associated antenna;

outputting a control signal to said downtilt controllers of at least two cell sites to adjust said downtilt angle of said associated antennas of said at least two cell sites such that the relationship between associated antennas is adjusted,

wherein said outputting step outputs said main control signals based on at least one operational measurement of said wireless communication system.

13. The method of claim 12, wherein said operational measurement is at least one of load, signal strength of signals received from two of said antennas, interference between signals received from said first and second antennas, a signal-to-noise ratio of signals received from one of said antennas, and a bit error rate of signals received from one of said antennas.

35. The method of claim 12, wherein said outputting step outputs said control signal to said at least two downtilt controllers to simultaneously adjust said downtilt angles of said associated antennas.

36. The method of claim 12, wherein said control signal indicates at least one of desired downtilt angles for said associated antennas and desired changes in said downtilt angles for said associated antennas.

14. A method of controlling antenna tilt in a wireless communication system, comprising:

providing a primary cell site including a primary antenna having an electrically controllable downtilt angle and a primary downtilt controller controlling said downtilt angle of said primary antenna, said primary antenna having a primary coverage area based on said downtilt angle thereof;

providing at least one secondary cell site including a secondary antenna having an electrically controllable downtilt angle and a secondary downtilt controller controlling said downtilt angle of said secondary antenna, said secondary antenna having a secondary coverage area based on said downtilt angle thereof, said secondary coverage area being adjacent to said primary coverage area;

first determining whether said primary coverage area is overloaded; and

outputting control signals to said primary and secondary downtilt controllers to adjust a boundary between said primary and secondary coverage areas by respectively changing said downtilt angle of said primary and secondary antennas when said primary coverage area is overloaded.

15. The method of claim 14, wherein said first determining step determines said primary coverage area is overloaded by monitoring a primary load on said primary coverage area, and determining when said primary load exceeds a first predetermined threshold.

16. The method of claim 14, further comprising:

monitoring secondary load on said secondary coverage area; and

wherein said outputting step outputs said control signals based on said secondary load on said secondary coverage area when said primary coverage area is overloaded.

17. The method of claim 16, further comprising:

second determining whether said secondary coverage area is available to handle additional load based on said secondary load; and

wherein

said outputting step outputs said control signals to adjust said boundary between said secondary coverage area and said primary coverage area when said primary coverage area is overloaded and said secondary coverage area is available.

18. The method of claim 17, wherein said second determining step determines said secondary coverage area is available when said secondary load is less than a second predetermined threshold.

19. The method of claim 14, wherein said outputting step outputs control signals to said primary downtilt controller to increase said downtilt angle of said primary antenna when said primary coverage area is overloaded.

20. The method of claim 14, wherein said outputting step outputs control signals to said secondary downtilt controller to decrease said downtilt angle of said second antenna when said primary coverage area is overloaded.

21. A wireless communication system, comprising:

a first antenna at a first cell site having an electrically controllable downtilt angle;

a first downtilt controller outputting a control signal to said first antenna to control said downtilt angle of said first antenna;

a second antenna at a second cell site having an electrically controllable downtilt angle;

a second downtilt controller outputting a control signal to said second antenna to control said downtilt angle of said second antenna;

a main controller outputting a main control signal to said first downtilt controller and said second downtilt controller to adjust a relationship between said first and second antennas,

wherein said main controller generates and outputs said main control signal based on at least one operational measurement of said wireless communication system.

22. The system of claim 21, wherein said operational measurement is at least one of load, signal strength of signals received from at least one of said first and second antennas, interference between signals received from at least one of said first and second antennas, a signal-to-noise ratio of signals received said first antenna, and a bit error rate of signals received from said first antenna.

23. The system of claim 21, wherein the wireless communication system is one of a time-division multiple access system, a code-division multiple access system and an analog system.

24. The system of claim 21, wherein said main controller generates and outputs said main control signal based on user input.

25. The system of claim 21, wherein said relationship is co-channel interference between signals received from said first and second antennas.

26. The system of claim 21, wherein said relationship is a boundary between coverage areas of said first and second antennas.

27. The system of claim 21, wherein said relationship is an amount by which signals received from said first antenna overlap signals received from said second antenna.

28. The system of claim 21, wherein said relationship is respective loads on said first and second antennas.

37. The system of claim 21, wherein said main controller outputs control signals to said first downtilt controller and said second downtilt controller to simultaneously adjust the downtilt angles of said first antenna and said second antenna.

38. The system of claim 21, wherein

said main control signal indicates one of a desired downtilt angle for said first antenna and a desired change in said downtilt angle of said first antenna, and

said main control signal further indicates one of a desired downtilt angle for said second antenna and a desired change in said downtilt angle of said antenna.

29. A wireless communication system, comprising:

a primary cell site including a primary antenna having an electrically controllable downtilt angle and a primary downtilt controller controlling said downtilt angle of said primary antenna, said primary antenna having a primary coverage area based on said downtilt angle thereof;

at least one secondary cell site including a secondary antenna having an electrically controllable downtilt angle and a secondary downtilt controller controlling said downtilt angle of said secondary antenna, said secondary antenna having a secondary coverage area based on said downtilt angle thereof, said secondary coverage area being adjacent to said primary coverage area; and

a main controller determining whether said primary coverage area is overloaded, and outputting control signals to said primary and secondary downtilt controllers to adjust a boundary between said primary and secondary coverage areas by respectively changing said downtilt angles of said primary and secondary antennas when said primary coverage area is overloaded,

wherein said main controller outputs control signals to said primary downtilt controller to simultaneously adjust said downtilt angle of said primary antenna and said down tilt angle of said secondary antenna.

30. A method of controlling antenna tilt in a controller of a wireless communication system, comprising:

first outputting a first control signal to a first antenna at a first cell site having an electrically controllable downtilt angle to control said downtilt angle of said first antenna;

second outputting a second control signal to a second antenna at a second cell site having an electrically controllable downtilt angle to control said downtilt angle of said second antenna; and

controlling said first and second outputting steps based on a determined adjustment of the relationship between said first antenna and said second antenna,

wherein said controlling step determines said adjustment based on at least one operational measurement of said wireless communication system.

32. The method of claim 30, wherein said operational measurement is at least one of load, signal strength of signals received from at least one of said first and second antennas, interference between signals received from at least one of said first and second antennas, a signal-to-noise ratio of signals received said first antenna, and a bit error rate of signals received from said first antenna.

33. The method of claim 30, wherein said relationship is one of co-channel interference between signals received from said first and second antennas, a boundary between coverage areas of said first and second antennas, an amount by which signals received from said first antenna overlap signals received from said second antenna, and respective loads on said first and second antennas.

39. The method of claim 30, wherein said first and second control signals simultaneously adjust the downtilt angles of said first antenna and said second antenna.

31. A method of controlling antenna tilt in a wireless communication system, comprising:

first outputting a first control signal to a first antenna having an electrically controllable downtilt angle to control said downtilt angle of said first antenna;

second outputting a second control signal to a second antenna having an electrically controllable downtilt angle to control said downtilt angle of said second antenna; and

controlling said first and second outputting steps such that the relationship between said first antenna and said second antenna is adjusted, wherein

said first control signal indicates one of a desired downtilt angle for said first antenna and a desired change in said downtilt angle of said first antenna, and

said second control signal indicates one of a desired downtilt angle for said second antenna and a desired change in said downtilt angle of said antenna.

34. A method of controlling antenna tilt in a wireless communication system, comprising:

providing a primary cell site including a primary antenna having an electrically controllable downtilt angle and a primary downtilt controller controlling said downtilt angle of said primary antenna, said primary antenna having a primary coverage area based on said downtilt angle thereof;

providing at least one secondary cell site including a secondary antenna having an electrically controllable downtilt angle and a secondary downtilt controller controlling said downtilt angle of said secondary antenna, said secondary antenna having a secondary coverage area based on said downtilt angle thereof, said secondary coverage area being adjacent to said primary coverage area;

first determining whether said primary coverage area is overloaded; and

outputting control signals to said primary and secondary downtilt controllers to adjust a boundary between said primary and secondary coverage areas by respectively changing said downtilt angle of said primary and secondary antennas when said primary coverage area is overloaded,

wherein said outputting step outputs control signals to said primary downtilt controller and secondary downtilt controller to simultaneously adjust the downtilt angle of said primary antenna and said secondary antenna.