Method for assigning telecommunications channels in a cellular telephone system
First Claim
1. A method of assigning K groups of available frequencies, the groups being numbered in order from k=1, 2, . . . K, each of the frequencies of the kth group differing from the respective frequencies of the kth+1 group by one channel, to a plurality of cells in an initial hexagonal pattern in a cellular telecommunications system, the method comprising:
- (a) assigning a first group of frequencies taken from the available frequencies to a first cell;
(b) for each cell adjacent to the first cell, assigning to it a distinct group of frequencies from the first group and from any group assigned to any other cell adjacent to the first cell, such that at least a second group and a third group of distinct frequencies remains unassigned after each cell adjacent to the first cell has been assigned frequencies;
(c) assigning frequencies from the second group to each of three second cells that are non-adjacent to the first cell and that are adjacent to a cell adjacent to the first cell, the three second cells being spaced substantially equally from each other about the first cell; and
(d) assigning frequencies from the third group to each of three third cells that are non-adjacent to the first cell and that are adjacent to a cell adjacent to the first cell, the three third cells being spaced substantially equally from each other about the first cell and the second cells; and
the respective frequencies of the first, second and third groups of frequencies differing from each other by at least three channels.
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Accused Products
Abstract
A method of assigning frequencies in a cellular telephone system in which a first group of the available frequencies is assigned to a first cell, and then distinct groups are assigned to adjacent cells, leaving at least one distinct group of frequencies free for later re-use. This system is applied to each cell in the system, so that for any cell, it and its adjacent cells do not use all of the frequencies in the system. For a first stage of cell splitting, frequencies are assigned from at least one non-adjacent cell (using the frequency re-use groups) to at least one part of the cell being split, while maintaining coverage of the cell from the same cell site. In a further stage of cell splitting in which there are adjacent first and second sets of three co-located end radiated cells, each radiated by directional antennas at first and second cell sites respectively, the cells are split by: locating a third cell site at about the mid-day point between the first and second cell sites; and radiating at least a third cell from the third cell site. An example is given based on 9 cells with sites arranged for end radiation of 3 cells from one site, thus reducing the number of cell sites. At each site the 3 co-located cells use frequency groups spaced to give protection against adjacent channel interference. The use of end radiated cells allows for less co-channel interference, as well as providing for a more distinct handoff between cells.
99 Citations
18 Claims
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1. A method of assigning K groups of available frequencies, the groups being numbered in order from k=1, 2, . . . K, each of the frequencies of the kth group differing from the respective frequencies of the kth+1 group by one channel, to a plurality of cells in an initial hexagonal pattern in a cellular telecommunications system, the method comprising:
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(a) assigning a first group of frequencies taken from the available frequencies to a first cell; (b) for each cell adjacent to the first cell, assigning to it a distinct group of frequencies from the first group and from any group assigned to any other cell adjacent to the first cell, such that at least a second group and a third group of distinct frequencies remains unassigned after each cell adjacent to the first cell has been assigned frequencies; (c) assigning frequencies from the second group to each of three second cells that are non-adjacent to the first cell and that are adjacent to a cell adjacent to the first cell, the three second cells being spaced substantially equally from each other about the first cell; and (d) assigning frequencies from the third group to each of three third cells that are non-adjacent to the first cell and that are adjacent to a cell adjacent to the first cell, the three third cells being spaced substantially equally from each other about the first cell and the second cells; and the respective frequencies of the first, second and third groups of frequencies differing from each other by at least three channels. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A cell layout in a cellular telecommunications system in which there are K groups of frequencies in order from k=1, 2, . . . K, each of the frequencies of the kth group differing from the respective frequencies of the kth+1 group by one channel, the layout comprising:
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a first cell having assigned to it a first group of frequencies; six adjacent cells distributed in a hexagonal pattern about the first cell having assigned of them a plurality of groups of frequencies; three second cells distributed regularly about the six adjacent cells so that their centers form an equilateral triangle with the first cell in the center of the equilateral triangle, the three second cells having assigned to them a second group of frequencies that are different from the plurality of groups of frequencies and the first group of frequencies; three third cells distributed regularly about the six adjacent cells so that their centers form an equilateral triangle with the first cell in the center of the equilateral triangle, the three third cells having assigned to them a third group of frequencies that are different from the plurality of groups of frequencies and the first and second groups of frequencies, and being located between respective pairs of the second cells; and the frequencies of the first, second and third groups of frequencies differing from each other respectively by at least three channels. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A cell layout for a cellular telecommunications system having a hexagonal pattern of cells and having available a set of at least K=9 groups of distinct frequencies, in order from k=1, 2, . . . K, each of the frequencies of the kth group differing from the respective frequencies of the kth+1 group by one channel, the cell layout comprising:
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a first cell having assigned to it the K=1 group of frequencies; adjacent cells to the first cell having assigned to them respectively in order around the first cell the K=2, 3, 8, 6, 5 and 9 groups of frequencies; a first set of three equally spaced cells adjacent to and located around the adjacent cells each of the first set of three equally spaced cells having assigned to them the K=4 groups of frequencies; and a second set of three equally spaced cells adjacent to and located around the adjacent cells and equally spaced between respective ones of the first set of three equally spaced cells, each of the second set of three equally spaced cells having assigned to them the K=7 group of frequencies. - View Dependent Claims (18)
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Specification