User's Manual Part 1

40 APCD-LM043-8.0 (DRAFT C)
3: Detailed Description
Table 2 shows the typical radio coverage (distance from the CCU) that the LMS4000 900 MHz
Radio Networks can achieve. Table 2 should be used as a planning guideline only, due to the
difficulty of accurately predicting radio coverage.
Table 2 Typical Radio Coverage
The following assumptions have been made in calculating the above ranges:
• For practical purposes, assume that typically 80% of the subscribers in the predicted
coverage area will be able to receive service. Higher coverage is possible but often
requires more extensive RF engineering.
• LOS (line of sight) means optical view and radio Fresnel clearance between the EUM
premise and the CCU antenna.
• Typical CCU antenna height of 130 ft. (40 m), at least 10 ft. (3 m) above the trees.
• Typical EUM antenna height (for outdoor antennas) of at least 13 ft. (4 m).
• The CCU EIRP has been maximized to +36 dBm in all cases. However, it is a
maximum of 34.8 dBm for indoor use. Refer to Appendix F on page 229 for further
guidelines.
• The EUM outdoor antenna (Yagi antenna, for example) has a gain of 9 dBi, and the
indoor antenna (WaveRider switched-beam diversity antenna) has a gain of 6.2 dBi.
• Coverage with the WaveRider indoor switched-beam diversity antenna depends on
the composition of the exterior walls and structure of the end-user’s premises. For
best results, the EUM antenna should be installed behind a window.
Actual results vary significantly due to local conditions. Coverage-area prediction that takes
into account local terrain and clutter factors provides a better estimate of coverage.
3.6 CCU–EUM Interface MAC Layer (Polling MAC)
This section describes the following the following aspects of the CCU–EUM Interface MAC
Layer (Polling MAC):
• EUM States on page 41
• Basic Operation of the Polling MAC on page 42
• Network Usage on page 43
• Association on page 43
EUM Installation Typical LOS Range Typical NLOS Range
Indoor Antenna
(path to CCU is through a
window)
3 mi (5 km) 1 mi (1.6 km)
Outdoor Antenna 5 mi (8 km) 2 mi (3.2 km)