Co-BCCH Introduction

What is Co-BCCH?
Co-BCCH: Common BCCH Cell, also called GSM900&DCS1800, Multi-band cell;
Based on Enhanced Concentric Cell Algorithm;
Two layers in a cell: UL (900M) and  OL (1800M);
The UL covers the whole cell area, The OL may not match the UL coverage area;
UL manages BCCH, SDCCH,PDCH and TCH channels, while OL only manages the TCH channels

Why Co-BCCH?
Improve capability:
    UL and OL share the BCCH, SDCCH, PDCH, and the TCH     channels will be increased accordingly
Frequency restrict:
    The frequency resource doesn’t support high     configuration, as in VNP totally we have 42 P-GSM     frequency, maximum support S4/4/4
Simplify network structure:
    Reduce number of cells in the network
    Reduce number of Location Area Codes
    Reduce number of neighboring cells
    Simplify multi-layer network into one layer network