Cell planning methods and apparatus, and networks configured based on same

• US 20060148484A1
• Filed: 03/06/2006
• Published: 07/06/2006
• Est. Priority Date: 09/23/2002
• Status: Active Grant

• Current Assignee: Cingular Wireless II LLC (AT&T, Inc.)
• Original Assignee: Cingular Wireless II LLC (AT&T, Inc.)
• Inventors: Zhang, Ming, MacDonald, Alan Denis
• Granted Patent: US 7,440,758 B2
• Time in Patent Office: Days
• US Class Current: 455/450
• CPC Class Codes: H04W 16/24 Cell structures
• CPC Class Codes: H04W 16/28 using beam steering

Abstract

Coverage areas for wireless networks are divided into a plurality of cells that are arranged in rows. Channel frequencies are assigned to cell sectors and associated with respective antenna axes. The antenna axes of adjacent rows are alternatingly rotated, thereby reducing co-channel interference. In an example, an available bandwidth is divided into twelve channel frequencies, so that a cell cluster includes four cells. Co-channel cells associated with half the channel frequencies are assigned to cells in the first row of cells, and the remainder are assigned to cells in the second row.

Claims

1. A method of arranging a wireless network coverage area, comprising:

defining at least a first set of channel frequencies and a second set of channel frequencies by allocating distinct channel frequencies selected from an available bandwidth to the first set and the second set of channel frequencies;

associating the first set and the second set of channel frequencies with a first set and a second set of antenna axis directions, respectively, such that each channel frequency is associated with a single antenna axis direction; and

assigning the first set of channel frequencies and the associated first set of antenna axis directions, and the second set of channel frequencies and the associated second set of antenna axis directions to respective pluralities of antennas situated in a the wireless coverage area, wherein the wireless coverage area comprises at least two rows of cells.

2. The method of claim 1, wherein each of the sets of antenna axis directions includes three antenna axis directions angularly spaced by about 120 degrees.

3. The method of claim 2, wherein the first set of antenna axis directions is rotated by about 60 degrees with respect to the second set of antenna axis directions.

4. The method of claim 3, further comprising associating 90 degree directional antennas with the antenna axis directions.

5. The method of claim 3, further comprising associating 60 degree directional antennas with the antenna axis directions.

6. The method of claim 3, further comprising associating 120 degree directional antennas with the antenna axis directions.

7. A method of assigning channel frequencies to a wireless network coverage area, the method comprising:

assigning each of the channel frequencies to a respective antenna axis;

allocating each of the channel frequencies to exactly one of at least three channel frequency groups; and

assigning the at least three channel frequency groups to a plurality of cells in the wireless network coverage area.

8. The method of claim 7, further comprising:

dividing a cellular coverage area into rows of cells; and

assigning a first group of channel frequencies and a second group of channel frequencies to selected cells in alternating rows of cells.

9. The method of claim 8, wherein each of the channel frequencies is assigned a single antenna axis direction.

10. A wireless communication system, comprising:

a first plurality of antenna sites situated in a coverage area and associated with a first set of antenna axes that are assigned channel frequencies from a first set of channel frequencies; and

a second plurality of antenna sites situated in the coverage area and associated with a second set of antenna axes that are assigned channel frequencies from a second set of channel frequencies, wherein the channel frequencies of the first set differ from the channel frequencies of the second set, and the second set of antenna axes is rotated with respect to the first set of antenna axes, wherein no three adjacent antenna sites share a common channel frequency.

11. The wireless communication system of claim 10, wherein the first plurality of antenna sites is provided with three antenna axes angularly spaced by about 120 degrees, and the second plurality of antenna sites is provided with three antenna axes angularly spaced by about 120 degrees.

12. The wireless communication system of claim 10, further comprising:

a third plurality of antenna sites situated in the coverage area and associated with the first set of antenna axes and assigned channel frequencies from a third set of channel frequencies; and

a fourth plurality of antenna sites situated in the coverage area, and associated with the second set of antenna axes and assigned channel frequencies from a fourth set of channel frequencies, wherein the channel frequencies of the first, second, third, and fourth sets are all different.

13. The wireless communication system of claim 12, further comprising arranging one antenna site of each of the first, second, third, and fourth pluralities of antenna sites to define a cell cluster, and situating cell clusters so as to substantially occupy the coverage area.

14. The wireless communication system of claim 10, wherein the first plurality of antenna sites is provided with three antenna axes angularly spaced by about 90 degrees, and the second plurality of antenna sites is provided with three antenna axes angularly spaced by about 90 degrees.

15. The wireless communication system of claim 10, wherein the first plurality of antenna sites is provided with three antenna axes angularly spaced by about 60 degrees, and the second plurality of antenna sites is provided with three antenna axes angularly spaced by about 60 degrees.