Remote Electrical Tilt (RET) System
The RET solution is a convenient and cost-effective solution for monitoring of AISG antenna line devices alarms and setting of electrical down-tilt angle of Variable Electrical Tilt (VET) antennas. A typical RET solution setup is shown in the diagram below:
The Comba RET solution consists of the following components:
A) Central Control Unit (CCU)
The CCU is the major component for controlling and monitoring the RCU, TMA and antenna line devices that are AISG compliant. It can be programmed to work with various manufacturers’ VET antennas by simply uploading the appropriate antenna definition/configuration files into it.
B) Remote Control Unit(RCU)
RCU-003(II-2) is a compact and light weight actuator that mechanically connects to the electrical phase shifter of Comba VET antenna for remote adjustment of electrical down-tilt angle. It is designed to comply with AISG 2.0 standards and works with AISG compliant Node B and antenna line devices.
C) Smart Bias Tee
The Smart Bias Tee is used to inject DC voltage and to modulate and demodulate remote control signals, via the RF coaxial cable, to antenna line devices such as TMA and RCU. It is designed to comply with AISG 2.0 standard and can be used as a lightning protection device for the BTS/Node B.
D) Variable Electrical Tilt (VET) Antenna
The VET antenna has an in-built electrical phase shifter module that allows remote electrical tilting of its vertical radiating beam. Comba has a comprehensive range of VET antennas for different frequency bands, different horizontal half power beam width and gain to suit different cellular coverage needs.
E) AISG Tower Mounted Amplifier (ATMA)
The ATMA is installed near the antenna at the tower top to improve receiver sensitivity of the base station, and call quality. Comba’s ATMA is designed to work with RCU in accordance to AISG standards.
F) AISG Control Cable
The AISG control cable is a five core cable that is fitted with a circular 8-pin Male connector on one end and a Female connector on the other. This cable is used to connect and transmit signals between AISG antenna line devices.
COMETS is a RET system manager software that is programmed to perform remote setting of electrical down tilting angle of VET antennas and monitoring of AISG antenna line devices alarms. It consists of a server and client architecture running on an IP backbone, as show below.
COMETS Main user interface
Users can connect remotely to the CCUs located at the base stations to execute various functions such as uploading of antenna configuration file, alarm management, site data management, data query etc..