Co-located omnidirectional and sectorized base station

• US 6,141,566 A
• Filed: 01/11/1999
• Issued: 10/31/2000
• Est. Priority Date: 01/11/1999
• Status: Expired due to Term

• Current Assignee: Tellabs Operations Incorporated (Infinera Corp.)
• Original Assignee: Tellabs Operations Incorporated (Infinera Corp.)
• Inventors: Kilpatrick, John A., Gerdisch, Mitchell R.
• Primary Examiner(s): Nguyen, Lee
• Assistant Examiner(s): Nguyen, Simon
• Application Number:
  US09/228,569
• Time in Patent Office: 659 Days
• Field of Search: 455/562, 455/522, 455/442, 455/453, 455/561, 455/456, 455/65, 455/101, 455/272, 455/275, 455/277.1, 455/277.2, 375/347, 370/249, 456/11.1, 456/9-10
• US Class Current: 455/562.1
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/0491 using two or more sectors, i.e. sector diversity
• CPC Class Codes: H04W 16/24 Cell structures
• CPC Class Codes: H04W 36/06 Reselecting a communication resource in the serving access point

Abstract

A preferred embodiment of the present invention provides a cell site base station configuration for a wireless communications system that makes use of a sectorized base station co-located with an omnidirectional base station. The sectorized base station has a sectorized antenna system and the omnidirectional base station has an omnidirectional antenna. The configuration may also include a controller that monitors the base station for communications links subject to adverse conditions and reassigns any such links to the omnidirectional base station. The adverse conditions monitored for may include multiple fade, equipment failure and a lack of available channels. The controller may also monitor the omnidirectional base station for links that can be moved to the sectorized base station and reassign any such links to the sectorized base station. The configuration may also include a network that interconnects the sectorized base station, the omnidirectional base station and the controller.

Claims

1. A cell site base station configuration for a wireless communication system, the base station configuration comprising:

a sectorized base station including a sectorized antenna system providing sectorized coverage for a cell;

an omnidirectional base station coupled to and co-located with said sectorized base station, said omnidirectional base station including an omnidirectional antenna providing omnidirectional coverage for the cell;

a plurality of reserve channels supported and held in reserve by said omnidirectional base station; and

a controller for preferentially maintaining communication link assignments between subscriber units and said sectorized base station by temporarily reassigning a disadvantaged subscriber unit affected by an adverse condition from said sectorized base station to a selected reserve channel of said omnidirectional base station, and reassigning said disadvantaged subscriber unit to said sectorized base station when said adverse condition abates, thereby freeing said selected reserve channel.

2. The base station configuration of claim 1, further comprising a network link for interconnecting said controller, said sectorized base station and said omnidirectional base station.

3. The base station configuration of claim 1, wherein said above condition is a multipath fade.

4. The base station configuration of claim 1, wherein said adverse condition is an equipment failure.

5. The base station configuration of claim 1, wherein said adverse condition is a lack of available channels.

6. The base station configuration of claim 1, wherein said controller further:

monitors said selected reserve channel for a second adverse condition affecting said selected reserve channel; and

reassigns said disadvantaged subscriber unit to said sectorized base station, thereby freeing said selected reserve channel.

7. The base station configuration of claim 1, wherein the subscriber units store a priority list of control channels implementing a preference for the sectorized base station.

8. The base station configuration of claim 1, wherein the sectorized base station provides a plurality of channels coded as preferred channels according to the IS-136 interim standard.

9. A method of operating a cell site, the method comprising:

operating a sectorized base station including a sectorized antenna system providing sectorized coverage at a cell site;

operating an omnidirectional base station coupled to and co-located with said sectorized base station, said omnidirectional base station including an omnidirectional antenna providing omnidirectional coverage for the cell;

holding in reserve a plurality of reserve channels at said omnidirectional base station; and

preferentially maintaining communication link assignments between subscriber units and said sectorized base station by temporarily reassigning a disadvantaged subscriber unit affected by an adverse condition from said sectorized base station to a selected reserve channel of said omnidirection base station, and reassigning said disadvantaged subscriber unit to said sectorized base station when said adverse condition abates, thereby freeing said selected reserve channel.

10. The method of claim 9, wherein said adverse condition is multipath fading.

11. The method of claim 9, wherein said adverse condition is equipment failure.

12. The method of claim 9, wherein said adverse condition is a lack of available channels.

13. The method of claim 9, the method further comprising the steps of:

monitoring said selected reserve channel for a second adverse condition affecting said selected reserve channel; and

reassigning said disadvantaged subscriber unit to said sectorized base station, thereby freeing said selected reserve channel.

14. The method of claim 9, further comprising the step of coding a plurality of sectorized base station channels according to the IS-136 interim standard.

15. A wireless communication network comprising:

a plurality of cells;

a plurality of cell sites distributed among said plurality of cells, wherein at least one of said plurality of cell sites comprises;

a sectorized base station including a sectorized antenna system providing sectorized coverage for a cell;

an omnidirectional base station coupled to and co-located with said sectorized base station, said omnidirectional base station including an omnidirectional antenna providing omnidirectional coverage for the cell;

a plurality of reserve channels supported and held in reserve by said omnidirectional base station; and

a controller for preferentially maintaining communication link assignments between subscriber units and said sectorized base station by temporarily reassigning a disadvantaged subscriber unit affected by an adverse condition from said sectorized base station to a selected reserve channel of said omnidirection base station, and reassigning said disadvantaged subscriber unit to said sectorized base station when said adverse condition abates, thereby freeing said selected reserve channel; and

a network interconnecting said plurality of cell sites.

16. The wireless communications network of claim 15, wherein said adverse condition is a multipath fade.

17. The wireless communications network of claim 15, wherein said adverse condition is an equipment failure.

18. The wireless communications network of claim 15, wherein said adverse condition is a lack of available channels.

19. The wireless communications network of claim 15, wherein said controller:

monitors said selected reserve channel for a second adverse condition affecting said selected reserve channel; and

reassigns said disadvantaged subscriber unit to said sectorized base station, thereby freeing said selected reserve channel.

20. The wireless communications network of claim 15, wherein the subscriber units store a plurality list of control channels implementing a preference for the sectorized base station.

21. The wireless communications network of claim 15, wherein the sectorized base station provides a plurality of channels coded as preferred channels according to the IS-136 interim standard.