WaveRider LMS4000, User Manual

Page: 82 / 282

5 Radio Network Planning
64 APCD-LM043-4.0
engineer, as specified in Appendix A Specifications, the minimum separation between
colocated channels is 6.6 MHz (an orthogonal adjacent channel) and requires a C/I ratio of 50
dB or better for non-interfering CCU operation. Once the antenna system gains and power
output of the CCU radio are accounted for, the only way to practically provide adequate
isolation for the required adjacent channel isolation is through the use of bandpass filters.
5.2.6 Single- or Multi-CAP Implementation
An important step in basic system design is to determine if a single CAP site adequately
covers your target serving area, or if a second CAP site, or multiple CAP sites, will be
required. The main factors that drive this decision are the RF coverage and the system
loading.
RF Coverage
The RF coverage of the sector is a function of many different factors.
Commercially available radio coverage prediction software calculates radio coverage based
on the following factors:
• Propagation characteristics (frequency, distance from the site)
• Radio characteristics (transmit power, receiver sensitivity)
• Antenna system and height
• Topography
• Clutter
Using this coverage prediction software, a qualified RF design engineer is able to produce RF
coverage estimates. Again, there are a number of independent RF engineering firms that can
provide this service, including the WaveRider Professional Services Group. If you have the
required software and in-house skill set, you can perform this coverage analysis yourself.