Point to multipoint radio access system

• US 5,838,670 A
• Filed: 01/29/1997
• Issued: 11/17/1998
• Est. Priority Date: 01/29/1997
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Billstrom, Jan-Olof V.
• Primary Examiner(s): TON, DANG T
• Application Number:
  US08/790,477
• Time in Patent Office: 657 Days
• Field of Search: 370/312, 370/315, 370/316, 370/328, 370/329, 370/335, 370/339, 370/343, 370/344, 370/480, 370/485, 370/499, 370/310, 370/337, 370/321, 370/347, 370/338, 370/276, 370/277, 455/422, 455/19, 455/13.3, 455/517, 455/524, 455/525
• US Class Current: 370/328
• CPC Class Codes: H04W 16/02 Resource partitioning among network components, e.g. reuse partitioning
• CPC Class Codes: H04W 16/12 Fixed resource partitioning
• CPC Class Codes: H04W 16/24 Cell structures
• CPC Class Codes: H04W 84/14 WLL [Wireless Local Loop]; RLL [Radio Local Loop]

Abstract

A robust and frequency-economic point to multipoint radio access microwave system combines the use of only two frequency bands and alternating polarizations. Base station antennae feeding adjacent sectors from a common base station site operate at least with different ones of two sets of channels. Moreover, sectors at adjacent base station sites (e.g., in adjacent cells) which are aligned with the sectors of the first base station site employ either a different set of channels or differing polarization. The two sets of channels can be two sets of frequencies (e.g., FDMA).

Claims

1. A radio access system comprising at least a first cell and a second cell, the first cell having at least four base station antennae, each of the four base station antennae transmitting a microwave carrier to one of a corresponding at least four sectors of the first cell, a band of the microwave carrier being divided into at least a first set of channels and a second set of channels, wherein a first base station antenna serving a first sector of the first cell transmits on the first set of channels and a second base station antenna serving a second sector of the first cell adjacent the first sector transmits on the second set of channels, and wherein at least two of the base station antennae of the first cell have differing polarizations;

the second cell being adjacent to the first cell, and wherein a second cell base station antenna transmits either on a different one of the separate sets of channels or with a different polarization than any first cell base station antenna with which it is aligned.

2. The system of claim 1, wherein the first base station antenna of the first cell and the second base station antenna of the first cell have differing polarization.

3. The system of claim 2, wherein a base station antenna serving a third sector of the first cell transmits on the first set of channels and has a same polarization as the base station antenna serving the first sector of the first cell, the third sector of the first cell being opposite and non-adjacent the first sector of the first cell.

8. The system of claim 1, wherein the first set of channels is a first set of frequencies and the second set of channels is a second set of frequencies.

9. The system of claim 1, wherein the second cell base station antenna transmits on a different one of the separate sets of channels than any first cell base station antenna with which it is aligned.

10. The system of claim 1, wherein the separate sets of channels comprise a first set of frequencies and a second set of frequencies.

11. The system of claim 1, wherein the base station antenna of the first sector of the first cell and the base station antenna of the second sector of the first cell have a same polarization.

12. The system of claim 11, wherein a base station antenna serving a third sector of the first cell transmits on the first set of channels and has a different polarization than the base station antenna serving the first sector of the first cell, the third sector of the first cell being opposite and non-adjacent the first sector of the first cell.

13. The system of claim 12, wherein the second cell which includes a second cell sector served by a second cell base station antenna, the second cell sector being adjacent the first sector of the first cell, the second cell base station antenna transmitting on the first set of channels and having a same polarization as the base station antenna of the first sector of the first cell.

14. The system of claim 13, wherein the system comprises four bordering cells which are adjacent to the first cell, and wherein a sector in any of the four bordering cells which is adjacent to an adjoining sector of the first cell is served by a bordering cell antenna, the bordering cell antenna using a same set of channels and a same polarization as the base station antenna which serves the adjoining sector of the first cell.

4. A radio access system comprising at least a first cell, the first cell having at least four base station antennae, each of the four base station antennae transmitting a microwave carrier to one of a corresponding at least four sectors of the first cell, a band of the microwave carrier being divided into at least a first set of channels and a second set of channels, wherein a first base station antenna serving a first sector transmits on the first set of channels and a second base station antenna serving a second sector adjacent the first sector transmits on the second set of channels, wherein at least two of the base station antennae of the first cell have differing polarizations, and wherein the first base station antenna and the second base station antenna have a same polarization.

5. The system of claim 4, wherein a third base station antenna serving a third sector transmits on the first set of channels and has a different polarization than the first base station antenna, the third sector being opposite and non-adjacent the first sector.

6. The system of claim 5, wherein the system comprises a second cell which includes a second cell sector served by a second cell base station antenna, the second cell sector being adjacent the first sector of the first cell, the second cell base station antenna transmitting on the first set of channels and having a same polarization as the first base station antenna.

7. The system of claim 5, wherein the system comprises four bordering cells which are adjacent to the first cell, and wherein a sector in any of the four bordering cells which is adjacent to an adjoining sector of the first cell is served by a bordering cell antenna, the bordering cell antenna using a same set of channels and a same polarization as the base station antenna which serves the adjoining sector of the first cell.

15. A method of operating a radio access system, the method comprising:

in each of a first cell and a second cell, using at least four base station antennae to transmit a microwave carrier to a corresponding at least four sectors of each cell;

dividing a band of the microwave carrier into at least a first set of channels and a second set of channels;

transmitting on the first set of channels from a base station antennae which serves a first sector of the first cell;

transmitting on the second set of channels from a base station antennae which serves a second sector of the first cell, the second sector of the first cell being adjacent the first sector of the first cell;

transmitting from a base station antenna which serves a first sector of the second cell either (1) on the second set of channels, or (2) with a differing polarization than the base station serving the first sector of the first cell;

the first sector of the second cell being aligned with the first sector of the first cell.

16. The method of claim 15, wherein the first set of channels is mutually exclusive from the second set of channels.

17. The method of claim 15, wherein the base station antenna of the first sector of the first cell and the second base station antenna of the first sector of the first cell have differing polarization.

18. The system of claim 17, further comprising:

transmitting on the first set of channels from a base station antenna serving a third sector of the first cell, the base station antenna serving the third sector of the first cell having a same polarization as the base station antenna serving the first sector of the first cell, the third sector of the first cell being opposite and non-adjacent the first sector of the first cell.

19. The method of claim 15, wherein the base station antenna of the first sector of the first cell and the base station antenna of the second sector of the first cell have a same polarization.

20. The system of claim 19, transmitting on the first set of channels from a base station antenna serving a third sector of the first cell, the base station antenna serving the third sector of the first cell having a different polarization than the base station antenna serving the first sector of the first cell, the third sector of the first cell being opposite and non-adjacent the first sector of the first cell.

21. The system of claim 20, further comprising:

serving a second cell which includes a second cell sector with a second cell base station antenna, the second cell sector being adjacent the first sector of the first cell;

transmitting from the second cell base station antenna on the first set of channels and with a same polarization as the base station antenna serving the first sector of the first cell.

25. The method of claim 15, wherein the first set of channels is a first set of frequencies and the second set of channels is a second set of frequencies.

22. A method of operating a radio access system, the method comprising:

using at least four base station antennae to transmit a microwave carrier to a corresponding at least four sectors of a cell;

dividing a band of the microwave carrier into at least a first set of channels and a second set of channels;

transmitting on the first set of channels from the a first of the base station antennae which serves a first sector;

transmitting on the second set of channels from the a second of the base station antennae which serves a second sector, the second sector being adjacent the first sector;

operating at least two of the base station antennae to have differing polarizations;

wherein the first base station antenna and the second base station antenna have a same polarization.

23. The system of claim 22, transmitting on the first set of channels from a third base station antenna serving a third sector, the third base station antenna having a different polarization than the first base station antenna, the third sector being opposite and non-adjacent the first sector.

24. The system of claim 23, further comprising:

serving a second cell which includes a second cell sector with a second cell base station antenna, the second cell sector being adjacent the first sector of the first cell;

transmitting from the second cell base station antenna on the first set of channels and with a same polarization as the first base station antenna.

26. A radio access system comprising at least a first cell and a second cell, the first cell and the second cell each having at least four base station antennae, each of the four base station antennae transmitting a microwave carrier to one of a corresponding at least four sectors of the first cell, a band of the microwave carrier being divided into at least a first set of channels and a second set of channels, wherein a base station antenna serving a first sector of the first cell transmits on the first set of channels and a base station antenna serving a second sector of the first cell adjacent the first sector of the first cell transmits on the second set of channels, wherein a first sector of the second cell is aligned with the first sector of the first cell, wherein the base station antenna serving the first sector of the second cell transmits in accordance with at least one of the following:

(1) on the second set of channels;

(2) with a differing polarization than the base station antenna serving the first sector of the first cell.

27. The system of claim 26, wherein the base station antenna of the first sector of the first cell and the second base station antenna of the first cell have differing polarization.

28. The system of claim 27, wherein a base station antenna serving a third sector of the first cell transmits on the first set of channels and has a same polarization as the base station antenna of the first sector of the first cell, the third sector of the first cell being opposite and non-adjacent the first sector of the first cell.

29. The system of claim 26, wherein the base station antenna of the first sector of the first cell and the base station antenna of the second sector of the first cell have a same polarization.

30. The system of claim 29, wherein a base station antenna serving a third sector of the first cell transmits on the first set of channels and has a different polarization than the base station antenna of the first sector of the first cell, the third sector of the first cell being opposite and non-adjacent the first sector of the first cell.

31. The system of claim 26, wherein the first set of channels is a first set of frequencies and the second set of channels is a second set of frequencies.