Method and system for reducing wireless multi-cell interferences through segregated channel assignments and segregated antenna beams

• US 6,907,246 B2
• Filed: 11/20/2001
• Issued: 06/14/2005
• Est. Priority Date: 11/20/2001
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Navini Networks, Inc. (Cisco Systems, Inc.)
• Inventors: Yang, Weidong, Jin, Hang, Xu, Guanghan
• Primary Examiner(s): Trinh, Sonny
• Assistant Examiner(s): TORRES, MARCOS L
• Application Number:
  US09/989,535
• Publication Number:
  US 20030211831A1
• Time in Patent Office: 1,302 Days
• Field of Search: 455446-447, 455/440, 455/443, 455/453, 455/455, 455/464, 455/62, 455/63, 455/450
• US Class Current: 455/447
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• 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 72/00 Local resource management
• CPC Class Codes: H04W 72/541 using the level of interference

Abstract

A method and system is disclosed for reducing multi-frequency signal interference in a wireless communication network. An available frequency spectrum is divided into a plurality of channels, a first wireless communication coverage unit is then segregated into a first number of geographical segments. After the segregated channels are grouped into a second number of channel blocks, each channel block is assigned to at least one of the segregated geographical segments with predetermined priorities. All the above steps are repeated for each neighboring wireless communication coverage unit of the first wireless communication coverage unit, wherein the channels in different channel blocks exhibit no higher mutual interference than the channels in the same channel block, and wherein the channel block assigned for each segregated segment of the first wireless communication coverage unit is different from the channel block assigned for the segregated segment of a second wireless communication coverage unit that immediately borders with the segregated segment of the first wireless coverage unit even if the first and second wireless communication coverage units share the same frequency spectrum.

Claims

1. A method for reducing multi-cell signal interferences in a wireless communication network, the method comprising:

dividing an available frequency spectrum into a plurality of channels;

segregating a first wireless communication coverage unit into a first number of geographical segments;

grouping the channels into a second number of channel blocks;

assigning each channel block to at least one of the segregated geographical segments with predetermined priorities; and

repeating the above steps for each neighboring wireless communication coverage unit of the first wireless communication coverage unit,

wherein the channels in different channel blocks exhibit no higher mutual interference than the channels in the same channel block, and wherein the channel block assigned for each segregated segment of the first wireless communication coverage unit is different from the channel block assigned for the segregated segment of a second wireless communication coverage unit that immediately borders with the segregated segment of the first wireless coverage unit even if the first and second wireless communication coverage units share the same frequency spectrum, wherein a location of a wireless terminal entering the first wireless communication coverage unit is detected by utilizing one or more segregated access code channels (ACCs) for the segregated geographical segments of the first wireless communication coverage unit to identify the wireless terminal wherein the ACCs and the segments bear a one-to-one relationship.

2. The method of claim 1 wherein an adaptive antenna array is used for detecting the location of the wireless terminal entering the wireless communication coverage unit, wherein at least one ACC physical attribute of the adaptive antenna array is unique to each geographical segment.

3. A method for reducing multi-cell signal interferences in a wireless communication network, the method comprising:

dividing an available frequency spectrum into a plurality of channels;

segregating a first wireless communication coverage unit into a first number of geographical segments;

grouping the channels into a second number of channel blocks;

assigning each channel block to at least one of the segregated geographical segments with predetermined priorities; and

repeating the above steps for each neighboring wireless communication coverage unit of the first wireless communication coverage unit, wherein the channels in different channel blocks exhibit no higher mutual interference than the channels in the same channel block, and wherein the channel block assigned for each segregated segment of the first wireless communication coverage unit is different from the channel block assigned for the segregated segment of a second wireless communication coverage unit that immediately borders with the segregated segment of the first wireless coverage unit even if the first and second wireless communication coverage units share the same frequency spectrum, wherein an exclusive antenna is used with an exclusive antenna pattern for covering each geographical segment for detecting a location of the wireless terminal entering the wireless communication.

4. A method for reducing multi-frequency signal interference in a wireless communication network, the network having a plurality of cells bordering on each other, each cell using a predetermined frequency spectrum for communications therein, the method comprising:

segregating a first cell into a first number of geographical segments;

dividing the predetermined frequency spectrum for the first cell into a plurality of channels;

establishing a channel assignment priority hierarchy for associating one or more channels to each geographical segment of the first cell;

repeating the above three steps for each cell bordering with the first cell; and

assigning channels to a terminal entering a segregated geographical segment of the first cell according to the established channel assignment priority hierarchy,

wherein the channel assignment priority hierarchy for the first cell and its bordering cells assures that the assigned channels are selected from the channels associated with the geographical segment of the first cell in which the terminal locates, and wherein the channels for such a geographical segment are different from the channels of a similarly segregated segment of another wireless cell that immediately borders therewith, wherein a location of the wireless terminal entering the first wireless communication coverage unit is detected by utilizing one or more segregated access code channels (ACCs) for the segregated geographical segments of the first wireless communication coverage unit to identify the wireless terminal wherein the ACCs and the segments bear a one-to-one relationship.

5. A method for reducing multi-frequency signal interference in a wireless communication network, the network having a plurality of cells bordering on each other, each cell using a predetermined frequency spectrum for communications therein, the method comprising:

segregating a first cell into a first number of geographical segments;

dividing the predetermined frequency spectrum for the first cell into a plurality of channels;

establishing a channel assignment priority hierarchy for associating one or more channels to each geographical segment of the first cell;

repeating the above three steps for each cell bordering with the first cell; and

assigning channels to a terminal entering a segregated geographical segment of the first cell according to the established channel assignment priority hierarchy, wherein the channel assignment priority hierarchy for the first cell and its bordering cells assures that the assigned channels are selected from the channels associated with the geographical segment of the first cell in which the terminal locates, and wherein the channels for such a geographical segment are different from the channels of a similarly segregated segment of another wireless cell that immediately borders therewith, wherein a path loss between a base station transceiver and the terminal is calculated for identifying a location of the terminal entering the wireless communication coverage unit.