User's Manual

PAS System
3
Technical Introduction
3. Technical Introduction
3.1 ACS Coverage Range
For ACS installation, the quantity and distribution of ACSs are affected by the
factors below:
z Geographical condition of the service area
z Subscriber distribution in the service area
z Expected traffic and service quality
3.1.1 Wireless Signal Transmission Mode
The frequency range of the PAS system is 1.9GHz which belongs to WIRELESS
LOCAL LOOP system; the wavelength is about 16cm, which is far shorter than
the building. The electric wave is poor at diffraction; the direct wave and reflect
wave are more intense than the diffraction wave. Figure3-1 shows the direct and
reflect of the electric wave in the urban area, where buildings are concentrated.
Figure3-1 Transmission Mode in Urban Area
The ACS coverage range in urban area is different from that in suburban area.
Moreover, the ACS coverage range is also influenced by the antenna height; the
higher is the antenna, the wider is the coverage range.