BS418 indoor base station

It is designed for fully IP based connectivity and allows for remote supervision and diagnostics, test, control, setting and software update, file transfer and SNMP. Its embedded Operate & Maintenance (OM) system is reached by means of Windows remote desktop.
The BS418 supports fully GPS synchronized discontinuous transmission. This allows a dramatic decrease in power consumption and increase a lifetime, as only the active TR412(s) needs to be powered, until traffic load requires more carriers to be on air.
BS418 fully supports voice + data services in full and half duplex modes, compliant with the TETRA air interface standard ETSI EN 300 392.
Access to all field replaceable units (FRU) is from the front, protected by a lockable door, and all external connectors are located on top of the rack.
The BS418 consists of the base station controller, the transceiver modules, the combiner system and the filter system. In the receiving path, a separate Tower Mounted Amplifier/Duplexer (TMD412) is an integrated functional part of BS418.

The TMD412 is designed for mast/tower mounting. Substantially the unit is a receiver amplifier with a built-in duplex filter.
The TMD412 amplification of the received signals fully eliminates the feeder cable loss by up to 8dBm, which gives superior radio coverage performance and link balance.

TR Cassette for BS418, CAS411
The CAS411 has slots for eight transceivers and two base station controllers. This cassette also contains a blower section with six high-flow blowers, which regulates the airflow through the base station in two steps controlled by the temperature in the transceivers.
Base Station Controller, BSC412
The operating system in the BSC412 executes DAMM’s TetraFlex® system software and may also execute TETRA system software from DAMM OEM Partners

By installing a second redundant BCS412 in the BS418 rack, reliability will be improved.

The DAMM Power Supply PS419 is a universal unit used in all versions of the DAMM Indoor Systems BS418.
The PS419 Cassette consists of a Power Supply Controller and up to three PS419 Power Supply units, to secure N+1 redundancy and allow for both standard and high-power transceivers.
Together with the PS418 Power Supply it is a dual output unit delivering both +14V and +26V output voltage, where the +14V output feeds all units in the indoor system and the +26V output feeds the power amplifier in the TR412.
The PS419 Power Supply is designed to run on both AC mains and DC battery input. In addition, it is able to charge a -48V back-up battery.
When running with AC input the PS419 Power Supply accepts 100–240VAC, 45–66Hz, covering all commonly used AC mains standards. It can power the DAMM Indoor System and simultaneously feed other units with -48VDC and charge an optionally connected -48V back-up battery.

Transceiver, TR412
The TR412 Transceiver is a complete TETRA carrier unit.
The TX section contains a linear, low noise transmitter linearized with a Cartesian loop. It can deliver a peak output power of 60W, giving a nominal output power of 25W TETRA.
Modulation and power control is performed in software of the DSP (Digital Signal Processor). The output amplifier is protected with a VSWR protection circuit and a temperature protection scheme. The forward and reflected power can be measured with built-in RMS power meters. An RFTL output is available for Base Station test.
The RX is a double super-heterodyne high dynamic range receiver provided with dual diversity with separate RX paths all the way to the DSP. The final selectivity, diversity combination, demodulation etc. is made in DSP software.

TX Combiner, TC411
The TC411 is a four-way TX cavity combiner module used to combine the
individual TX outputs to a single cable.
The TC411 consists of four motor-tuned ¼ or ¾ λ TEM resonators. The inputs are provided with dual circulators with high-power loads, which are able to dissipate the reflected power when the TX antenna is missing, or the cavity is tuned to a frequency not matching the transmitter.
An RF detector is provided on the high-power load used for manual adjustment and alarm generation.
The TC411 is equipped with the TCC411 TC Combiner Controller with built-in micro-controller, which controls the motors.
At power-up, the micro-controller initializes the tuning position against a mechanical end stop. The TCC411 is connected to the O&M UART bus and can be reached with O&M commands from the BSC412.

BS418 8 carriers datasheet (.pdf, 600k)

BS418 16 carriers datasheet (.pdf, 750k)

Characteristics