Channel allocation pattern in a cellular communications system

• US 5,901,356 A
• Filed: 05/02/1996
• Issued: 05/04/1999
• Est. Priority Date: 08/04/1994
• Status: Expired due to Term

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Northern Telecom Limited (Nortel Networks Corporation)
• Inventors: Hudson, John Edward
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): Luu, Chieu V.
• Application Number:
  US08/628,738
• Time in Patent Office: 1,097 Days
• Field of Search: 455/447, 455/450, 455/451, 455/452, 455/453, 370/297
• US Class Current: 455/451
• 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 28/16 Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]

Abstract

A method of allocating channels in a cellular system in which sectored base sites serve subscribers equipped with directional antennas. A plurality of available communication channels is divided into channel subsets. Base sites are arranged in clusters, and within each cluster: the number of channel subsets is equal to the number of base sites, is greater than the number of sectors per base site and is not a multiple of the number of sectors per base site; each channel subset is allocated once in each of the different sector directions; and the allocation pattern is not repeated within the cluster, whereby to minimize co-channel interference.

Claims

1. A method of defining a channel allocation pattern in a cellular communications system in which sectored base sites having sectors pointing in different directions serve directional subscribers, the method including providing a plurality of available channels which is divided into channel subsets and arranging the base sites in clusters wherein within each said cluster:

the number of channel subsets is equal to the number of base sites, is greater than the number of sectors per base site and is not a multiple of the number of sectors per base site;

each channel subset is allocated once in each of the different sector directions, and;

the allocation pattern is not repeated within the cluster, whereby to minimise co-channel interference.

2. A method of defining a channel allocation pattern as claimed in claim 1 wherein the channel subsets allocated to the sectors of one base site are a rotation of those applied to an adjacent base site.

3. A method of defining a channel allocation pattern as claimed in claim 1 wherein the base sites edge-excite cells.

4. A method of defining a channel allocation pattern as claimed in claim 3 wherein a tessellating pattern of cells, each cell using a different channel subset, is repeated across an area and the sectored base sites are overlaid on this pattern at intersections of the cells.

5. A method of defining a channel allocation pattern as claimed in claim 3 wherein the base sites are tri-sectored and the clusters comprise four base sites, four channel subsets being used within each of the clusters.

6. A method of defining a channel allocation pattern as claimed in claim 3 wherein the base sites are tri-sectored and the clusters comprise seven base sites, seven channel subsets being used within each of the clusters.

7. A method of defining a channel allocation pattern as claimed in claim 4 wherein the base sites are tri-sectored and the clusters comprise four base sites, four channels being used within each of the clusters.

8. A method of defining a channel allocation pattern as claimed in claim 4 wherein the base sites are tri-sectored and the clusters comprise seven base sites, seven channels being used within each of the clusters.

9. A cellular communications system in which sectored base sites having sectors pointing in different directions serve directional subscribers, the base sites being arranged in clusters, there being a plurality of available channels which is divided into channel subsets and wherein the pattern of channels allocated within each said cluster is such that:

the number of channel subsets is equal to the number of base sites, is greater than the number of sectors per base site and is not a multiple of the number of sectors per base site;

each channel subset is allocated once in each of the different sector directions, and;

the allocation pattern is not repeated within the cluster, whereby to minimise co-channel interference.

10. A cellular communications system as claimed in claim 9 in which the directional subscribers are fixed subscribers.