13. May 2015

COAX

Telegärtner RET Cables

Why a Remote Electrical Tilt System?

Why a RET System?

With the growing demand on network performance, coverage and capacity have never been so important to network operators to keep customer satisfaction and retention high and to gain maximum revenue from their network.  One way for engineers to increase these is by adjusting an antenna’s downtilt.  Previously this meant an engineer was needed up with the antenna and the site had to be switched off for several hours, meaning downtime and loss of revenue for the network operator as well as customer dissatisfaction.

Mobile networks now have the possibility to control the electrical downtilt of the antennas remotely.  These Remote Electrical Tilt, or RET systems require Telegaertner RET cables to connect the Master Control Unit (MCU) to the Remote Control Unit (RCU) which is attached directly to the antenna or in some cases is an internal component of the antenna.  By using these systems, a network operator can adjust the tilt of the antenna without shutting down the system, or the requirement for specialised teams. In combination with a mechanical tilt, it`s possible to get the exact antenna pattern you are aiming for your individual cell.

Analyzing pattern-diagrams, we find two different predictions:

  • With the mechanical tilt, the coverage is reduced in central direction (in comparison with electrical tilt), but the coverage area in side-directions are increased.
  • With the electrical tilt, the coverage area suffers a uniform reduction in the direction of the antenna Azimuth, but increases in central direction.

 So the advantages of one tilt type are very based on it`s application.

Telegärtner’s standard range

Our RET cables are offered in a variety of lengths from 0.5 m to 100 m, with the shorter lengths being available to “daisy chain” multiple RET modules together at the top of the tower or building. By connecting the modules together, you reduce the number of cables required from the MCU to the antennas.

The cables are all compliant to AISG 2.0 and 1.1 and as you would expect from Telegärtner we only use high quality European components. The cable itself is halogen free and flame retardant and the connectors are according to IEC 60130-9. They have fully soldered contacts and are IP67 when mated.

Variations on the standard

Due to variations on the OEM interconnect, Telegärtner also offers two different styles of RET Cable with waterproof D Subs.  Variation 1 offers the usual 8 pin female connector to IEC 60130-9 at one end with a 9 way D Sub waterproof male connector with a rectangular formed o-ring to create the IP67 seal, which seals directly against the mating half.  Variation 2 is as variation 1 but instead of the o-ring uses a skirt to create the IP67 seal to allow for a raised mating half.  Again, both variants are available in a variety of lengths from 0.5 m to 100 m. 

We have also designed some customer specific variations on all the above standard cables.  For example, different pin-outs, male to male or female to female, threads removed.