User's Manual
Table Of Contents
- SECTION 6 Installing Unison Accel
- 6.1 Installation Requirements
- 6.2 Safety Precautions
- 6.3 Preparing for System Installation
- 6.4 Unison Accel Installation Procedures
- 6.5 Interfacing an Accel Hub to a Base Station or a Roof-top Antenna
- 6.6 Connecting Contact Alarms to an Accel System
- 6.7 Alarm Monitoring Connectivity Options
- SECTION 7 Replacing Unison Accel Components in an Operational System
- SECTION 8 Maintenance, Troubleshooting, and Technical Assistance
- APPENDIX A Cables and Connectors
- APPENDIX B InterReach Unison Accel Property Sheet
- APPENDIX C Compliance
- APPENDIX D Release Notes
5-42 InterReach Unison Accel Installation, Operation, and Reference Manual PN 9000-10
620021-0 Rev. A
5.5 Connecting a Main Hub to a Base Station
The first consideration when connecting Unison Main Hubs to a base station is to
ensure there is an equal amount of loss through cables, combiners, etc. from the base
station to the Main Hubs. For this example, assume that the base station will have
simplex connections, one uplink and one downlink. Each of these connections will
need to be divided to equilibrate power for each Main Hub. For example, two Main
Hubs will require a 2×1 combiner/divider; four Main Hubs will require a 4×1 com-
biner/divider; and so on.
Figure 5-2 Connecting Main Hubs to a Simplex Base Station
When connecting a Unison Main Hub to a base station, also consider the following:
1. The downlink power from the base station must be attenuated enough so that the
power radiated by the RAU does not exceed the maximum power per carrier listed
in Section 5.1, “Maximum Output Power per Carrier at RAU,” on page 5-3.
2. The uplink attenuation should be small enough that the sensitivity of the overall
system is limited by Unison, not by the attenuator. However, some base stations
will trigger alarms if the noise or signal levels are too high. In this case the attenu-
ation will have to be large enough to prevent this from happening.
If, in an area covered by Unison, a mobile phone indicates good signal strength but
consistently has difficulty completing calls, it is possible that the attenuation between
Unison and the base station needs to be adjusted. In other words, it is possible that if
the uplink is over-attenuated, the downlink power will provide good coverage, but the
uplink coverage distance will be small.
When there is an excessive amount of loss between the Main Hub uplink and the base
station, the uplink system gain can be increased to as much as 15 dB to prevent a
reduction in the overall system sensitivity.
Base Station
2 × 1 combiner/divider
Downlink/Forward
Main Hub 1
Main Hub 2
Uplink/Reverse