One way to increase to subscriber capacity of a cellular network is
replace the omni-directional antenna at each base station by three
(or six) sector antennas of 120 (or 60) degrees opening.
Each sector can be considered as a new cell, with its own (set of) frequency channel(s).
The base station can either be located at
The use of directional sector antennas substantially reduces the interference among co-channel cells.
This allows denser frequency reuse.
- the center of the original (large) cell, or
- the corners of the original (large) cell.
Sectorization is less expensive than cell-splitting,
as it does not require the acquisition of new base station sites.