Method and system for adapting a channel assignment plan to include shared frequency channels

A system for adapting a channel assignment plan for a cellular communication network to include shared frequency channels, said channel assignment plan distinguishing frequency channels assigned to a plurality of cells, and said system comprising:

• an input element for receiving said channel assignment plan;
• a memory element in communication with said input element for storing said channel assignment plan;
• a borrower cell identifier, in communication with said memory element, for identifying a borrower cell from said plurality of cells in response to said channel assignment plan, said borrower cell identifier including:
• a detector for detecting candidate borrower cells from said plurality of cells, each of said candidate borrower cells being assigned subsets of said frequency channels, each of said subsets exhibiting deficiencies in a quantity of said frequency channels assigned to corresponding ones of said candidate borrower cells;
• and
• a needier cell selector for specifying a first one of said candidate borrower cells to be said borrower cell, said first borrower cell having a greater deficiency in said quantity of said frequency channels assigned to said needier borrower cell than remaining ones of said candidate borrower cells;
• a donor cell selector, in communication with said memory element, for selecting a donor cell from said plurality of cells, said donor cell selector including:
• a load factor determiner for ascertaining a load factor for each of said cells from said plurality of cells excluding said identified borrower cell, said load factor representing those of said frequency channels assigned to a corresponding one of said cells that are previously designated as said shared frequency channels;
• and
• a better cell selector for specifying a first one of said cells to be said donor cell, said first cell exhibiting said load factor that is less than said load factors for the remaining ones of said cells;
• a channel selector for choosing a candidate frequency channel from a subset of said frequency channels assigned to said donor cell;
• a channel evaluator for determining a quality measure for said candidate frequency channel;
• and
• channel designator for designating said candidate frequency channel as one of said shared frequency channels in said channel assignment plan when quality measure exceeds a channel sharing constraint.

In a cellular communication network having a channel assignment plan that distinguishes frequency channels assigned to a plurality of cells, a method for adapting said channel assignment plan to include shared frequency channels comprising the steps of:

• a) identifying a borrower cell from said plurality of cells, said borrower cell being assigned a first subset of said frequency channels, said first subset having a deficiency in a quantity of said frequency channels assigned to said borrower cell;
• b) selecting a donor cell from said plurality of cells in response to a load factor for said donor cell, said donor cell being assigned a second subset of said frequency channels;
• c) verifying frequency separations between said candidate frequency channel and each of said frequency channels of said second subset exceed a frequency separation threshold;
• d) when each of said frequency separations exceed said frequency separation threshold, verifying a co-channel carrier-to-interference (C/I) ratio value for said borrower cell exceeds a co-channel C/I ratio threshold;
• e) when said co-channel C/I ratio value exceeds said co-channel C/I ratio threshold, verifying an adjacent channel C/I ratio value for said borrower cell exceeds an adjacent channel C/I ratio threshold;
• and
• f) designating said candidate frequency channel as one of said shared frequency channels in said channel assignment plan in response to said step e).