Search International and National Patent Collections

1. (WO1998052364) A METHOD OF MAXIMIZING SPECTRAL EFFICIENCY IN A CELLULAR COMMUNICATIONS SYSTEM

Pub. No.:    WO/1998/052364    International Application No.:    PCT/US1998/009727
Publication Date: Fri Nov 20 00:59:59 CET 1998 International Filing Date: Thu May 14 01:59:59 CEST 1998
IPC: H04W 16/02
H04W 16/12
H04W 16/32
Applicants: NEXTEL COMMUNICATIONS, INC.
Inventors: SCHWINGHAMMER, Pat
WESTALL, Murry
STEVENS, Randy
WESTLAKE, Leonard, L.
Title: A METHOD OF MAXIMIZING SPECTRAL EFFICIENCY IN A CELLULAR COMMUNICATIONS SYSTEM
Abstract:
A system and method for operating a cellular communication system is disclosed wherein frequency reuse of available carrier frequencies is maximized, thereby maximizing system traffic capacity. The invention includes an outer cell grid generated by a plurality of base station transceivers (12) connected to a common network controller (10). Within the grid of outer cells is at least one overlapping sub-grid of inner cells that may be generated by the same base stations (12) as the outer cells, or which may be generated using separate base station transceivers located within the outer cell. At least two frequency reuse patterns are applied to the cells, one pattern for the outer cells and another, tighter pattern for the inner cells. The inner cells (16) are defined and limited by a predetermined threshold co-channel interference level (C/I), the interference emanating from adjacent inner cells operating at the same frequencies. The invention also includes mobile units that can directly measure both RSSI and C/I of the serving cell and associated neighbor cells. The mobile units take periodic measurement reports which are transmitted to the network when a predetermined threshold interference condition has been met. The network controller (10) than switches the mobile unit to one of the neighbor cells. The present method and system can be used with other traditional techniques for optimizing frequency reuse, such as underlay/overlay or microcellular methods.