WaveRider LMS4000 User Manual page 49

The CCU and EUM transmit power can each be set to +15 dBm (LOW power setting) to
address special or regional applications of the LMS4000, or for bench testing.
Receive Sensitivity
The receive sensitivity (received signal required to attain a raw data BER of 10
using 1000-byte packets) of the CCU and EUM is < -86 dBm, measured at the unit's RF
connector.
Antenna Connector
The RF connector used on the CCU and EUM is a WaveRider-proprietary connector. As noted
above, the use of a proprietary antenna connector is mandated by FCC requirements for a
unique RF connector on ISM products.
Antenna Control (EUM)
A DC voltage (5 VDC or 7.5 VDC) is applied to the EUM RF connector for powering and
controlling the WaveRider diversity antenna. One beam pattern is selected if the voltage is 5
VDC. A second beam pattern is selected if the voltage is 7.5 VDC.
Propagation Path
CCU and EUM radios and antennas provide the basis for excellent radio propagation in both
line of sight (LOS) and non line of sight (NLOS) EUM installations. Radio propagation in the
902 – 928 MHz ISM band is superior to propagation in higher ISM bands for several reasons:
• Lower free space loss
• Lower cable loss
• Lower vegetation loss
• Better wall and glass penetration
• More signal recovery from diffraction
• More signal recovery from reflections
Radio line of sight exists when there is a clear optical path between the CCU and EUM
antennas, as well as adequate clearance of the path over terrain, foliage, and buildings. This
clearance requirement is called the Fresnel clearance. The required clearance varies along
the path and reaches a maximum at the path midpoint. If you have a path with Fresnel
clearance, the loss between the antennas is generally equivalent to free-space loss and can
be readily calculated.
APCD-LM043-4.0
CAUTION: The EUM sends DC power and control voltages
through the RF connector to the switched-beam diversity
antenna. You must use WaveRider-approved indoor or outdoor
antennas; otherwise, you could inadvertently short out the DC
voltage and damage the EUM. Contact WaveRider Technical
Support for a list of approved antennas.
3 Detailed Description
-5
or better
31