Radio communications system

• US 6,615,047 B1
• Filed: 04/08/1999
• Issued: 09/02/2003
• Est. Priority Date: 04/08/1999
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Chatani, Yoshiyuki, Yasooka, Kousuke, Shibata, Nobuyuki
• Primary Examiner(s): Bost, Dwayne
• Assistant Examiner(s): WEST, LEWIS G
• Application Number:
  US09/288,013
• Time in Patent Office: 1,608 Days
• Field of Search: 455/562, 455/446, 455/447, 455/450, 455/451, 455/452
• US Class Current: 455/446
• 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]
• CPC Class Codes: H04W 4/08 User group management
• CPC Class Codes: H04W 76/10 Connection setup

Abstract

A cell group is formed from three cells, each of which has a site equipped with antennas. The antennas differ from one another in terms of horizontal orientation and cover all horizontal directions. The cell groups are arranged in a repeating pattern such that a cell having a site assigned different frequency is interposed between cell groups assigned the same frequency, thereby constituting a minimum unit area to be repeated.

Claims

1. A radio communications system for establishing radio communication between arbitrary sites and fixed terminal stations, each of the fixed terminal stations being directional and disposed in a cell centered on a respective one of the arbitrary sites, wherein

each of the sites is provided with three antennas of equal horizontal beam width and whose orientations are horizontally offset from one another;

beams emanated from the three antennas taken together cover all horizontal directions;

corresponding ones of the antennas assigned the same frequency as that of the site are arranged in the same sequence;

the radio communications system further comprising;

a cell group comprising three cells centered on three respective sites, in which the centers of beams emanated from ones of the respective three antennas associated with each of the three sites, which ones are assigned the same frequency are offset from one site to another site by an amount approximately equal to a beam width;

wherein

the three cells are adjacent to one another;

the cell group, further comprises a plurality of groups of different frequencies and constitutes a minimum unit area to be repeated; and

the minimum unit areas are repeatedly arranged in longitudinal and lateral directions.

2. The radio communications system as defined in claim 1, wherein the minimum unit area is repeatedly arranged in the vertical direction so as to become horizontally offset from one another.

3. The radio communications system as defined in claim 1, wherein the, minimum unit area is repeatedly, arranged such that a column of minimum unit areas becomes vertically offset from another column of minimum unit areas.

4. A radio communications system for establishing radio communication between arbitrary sites and fixed terminal stations, each of the fixed terminal stations being directional and disposed in a cell centered on a respective one of the arbitrary sites, wherein

each of the sites is provided with “

n”

sector antennas wherein each of the “

n”

sector antennas has equal horizontal beam width and wherein orientations associated with the each are horizontally offset from one another, wherein “

n”

represents a positive integer equal to or greater than 4;

beams emanated from the “

n”

sector antennas taken together cover all horizontal directions;

frequencies are arranged such that ones of the “

n”

sectors within a cell associated with the each of the sites are assigned the same frequency every “

m”

sectors where “

m”

represents a positive integer of equal to or greater than 2, and m<

n;

corresponding ones of the antennas assigned the same frequency as that of the site are arranged in the same sequence;

the radio communications system further comprising;

a cell group constituting a minimum unit area to be repeated, the cell group comprising “

m”

adjacent cells each assigned a group of frequencies, wherein centers of beams emanated from the corresponding ones of the “

n”

sector antennas assigned the same frequency are horizontally offset from one site to another site by an amount approximately equal to one beam width;

wherein the minimum unit area is repeatedly arranged in longitudinal and lateral directions.

5. The radio communications system as defined in claim 4, wherein the minimum unit area is repeatedly arranged in the vertical direction so as to become horizontally offset from one another.

6. The radio communications system as defined in claim 4, wherein the minimum unit area is repeatedly arranged such that a column of minimum unit areas becomes vertically offset from another column of minimum unit areas.

7. A radio communications system for establishing radio communication between arbitrary sites and fixed terminal stations, each of the fixed terminal stations being directional and disposed in a cell centered on a respective one of the arbitrary sites, wherein

each of the sites is provided with three antennas which are equal in horizontal beam width and whose orientations are horizontally offset from one another;

beams emanated from the three antennas taken together cover all horizontal directions;

corresponding ones of the antennas assigned the same frequency as that of the site are arranged in the same sequence;

the radio communications system further comprising;

a cell group comprising three cells, each of the three cells assigned a group of frequencies, the cell group constituting a minimum area to be repeated, wherein centers of beams emanated from respective ones of the respective three antennas assigned the same frequency are offset from one site to another site by an amount approximately equal to one beam width;

wherein the three cells are further arranged such than an additional cell assigned different frequencies from any of the groups of frequencies is interposed between proximate cells; and

wherein the minimum unit area is repeatedly arranged in longitudinal and lateral directions.

8. The radio communications system as defined in claim 7, wherein the minimum unit area is repeatedly arranged in the vertical direction so as to become horizontally offset from one another.

9. The radio communications system as defined in claim 7, wherein the minimum unit area is repeatedly arranged such that a column of minimum unit areas becomes vertically offset from another column of minimum unit areas.

10. A radio communications system for establishing radio communication between arbitrary sites and fixed terminal stations, each of the fixed terminal stations being directional and disposed in a cell centered on a respective one of the arbitrary sites, wherein

each of the sites is provided with “

n”

sector antennas wherein each of the “

n”

sector antennas has equal horizontal beam width and wherein orientations associated with the each are horizontally offset from one another, wherein “

n”

represents a positive integer equal to or greater than 4;

beams emanated from the “

n”

sector antennas taken together cover all horizontal directions;

frequencies are arranged such that ones of the “

n”

sectors within a cell are assigned the same frequency every “

m”

sectors where “

m”

represents a positive integer of equal to or greater than 2, and m<

n;

corresponding ones of the antennas assigned the same frequency as that of the site are arranged in the same sequence;

a cell group constituting a minimum unit area to be repeated, the cell group comprising “

m”

adjacent cells each assigned a group of different frequencies, wherein centers of beams emanated from the corresponding ones of the “

n”

sector antennas assigned the same frequency are horizontally offset from one site to another site by an amount approximately equal to one beam width;

the “

m”

adjacent cells associated with the cell group are further arranged such that “

L”

additional each assigned different frequencies from any of the group of different frequencies are interposed between the “

m”

proximate cells, where “

L”

designates 0 or a positive integer greater than 1;

wherein the minimum unit area is repeatedly arranged in longitudinal and lateral directions.

11. The radio communications system as defined in claim 10,

wherein the minimum unit area is repeatedly arranged in the vertical direction so as to become horizontally offset from one another.

12. The radio communications system as defined in claim 10, wherein the minimum unit area is repeatedly arranged such that a column of minimum unit areas becomes vertically offset from another column of minimum unit areas.

13. A radio communications system for establishing radio communication comprising:

one or more cell groups each having at least three adjacent cells;

wherein each of the adjacent cells has at least “

n”

antennas with equal horizontal beam width, the “

n”

antennas associated with corresponding “

n”

cell sectors, the “

n⇄

antennas directed approximately (360/“

n”

)degrees apart from each other in a horizontal plane;

wherein each of three adjacent cells in the one or more cell groups are assigned a plurality of frequencies;

wherein corresponding ones of the “

n”

antennas are assigned the same frequency every “

m”

of the “

n”

corresponding cell sectors and wherein the corresponding ones of the “

n”

antennas assigned the same frequency in each of the three adjacent cells are further arranged in the same sequence; and

wherein one or more cell groups constitutes a minimum unit area to be repeated over a geographical area associated with the radio communications system; and

wherein a plurality of minimum unit areas are repeatedly arranged in longitudinal and lateral directions.

14. The radio communications system of claim 13, wherein the corresponding ones of the “

n”

antennas assigned the same frequency in each of the three adjacent cells are further offset by at least an amount approximately equal to (360/“

n”

)degrees from one of the three adjacent cells to the next.

15. The radio communications system of claim 13, wherein the adjacent cells are further arranged such that one or more additional cells each assigned a different plurality of frequencies are interposed between ones of the three adjacent cells.

16. The radio communications system of claim 13, where “

n”

is a positive integer equal to or greater than 3, “

m”

is a positive integer equal to or greater than 2, and where “

m”

<

“

n”

.

17. A method for establishing radio communication comprising:

arranging one or more cell groups each having at least three adjacent cells;

wherein each of the adjacent cells has at least “

n”

antennas with equal horizontal beam width, the “

n”

antennas associated with corresponding “

n”

cell sectors, the “

n”

antennas directed approximately (360/“

n”

)degrees apart from each other in a horizontal plane;

assigning a plurality of frequencies to each of three adjacent cells in the one or more cell groups; and

assigning corresponding ones of the “

n”

antennas the same frequency every “

m”

of the “

n”

corresponding cell sectors, wherein the corresponding ones of the “

n”

antennas assigned the same frequency in each of the three adjacent cells are further arranged in the same sequence;

wherein one or more cell groups constitutes a minimum unit area to be repeated over a geographical area associated with the radio communications system; and

wherein a plurality of minimum unit areas are repeatedly arranged in longitudinal and lateral directions.

18. The method of claim 17, wherein the step of assigning further comprises:

assigning corresponding ones of the “

n”

antennas the same frequency every “

m”

of the “

n”

corresponding cell sectors and offsetting the corresponding ones of the “

n”

antennas assigned the same frequency in each of the three adjacent cells by at least an amount approximately equal to (360/“

n”

)degrees from one of the three adjacent cells to the next.

19. The method of claim 17, wherein the three adjacent cells are further arranged such that one or more additional cells each assigned a different plurality of frequencies are interposed between ones of the three adjacent cells.

20. The method of claim 18, wherein “

n”

is a positive integer equal to or greater than 3, “

m”

is a positive integer equal to or greater than 2, and where “

m”

<

“

n”

.