Method and apparatus of assigning and sharing channels in a cellular

Abstract

A method of assigning and sharing carriers in a cellular communications system having a plurality of cells forming a plurality of cell clusters of size N. Each cell has at least one base station capable of sending and receiving signals and each cell has a plurality of adjacent cells. A plurality of distinct carriers are allotted for use by the system and divided into N groups which are assigned among the N cells of each cell cluster so that each cell cluster has a substantially similar assignment of distinct carrier groups. Each group of distinct carriers is divided into a plurality of carrier subgroups wherein each subgroup of carriers of a cell substantially corresponds to an adjacent cell. The subgroups of carriers are respectively designated for borrowing by cells adjacent to a corresponding cell. When all of the carriers assigned to a cell are utilized, a carrier can be borrowed at limited transmitted power, from a corresponding subgroup of carriers of an adjacent cellular gateway. The borrowed carrier is used with limited transmitted power so that co-channel interference caused by the carrier borrowing is essentially the same as that without carrier borrowing. A method is also provided for assigning and sharing carriers and prioritizing the order of return of the carriers from a borrowing cell to a lending cell.