Case Studies / Digital Radio-Relay Link Sorica - Ziri with SparkWave 18AR Active Repeater
Within the past ten years Telecom Slovenia completely digitalized
their telecommunication network. Telecom Slovenia - Business Unit Kranj
finished digitalization in 1999 by connecting the subscribers to the new
EWSD exchange, and by putting into operation a new digital link to Davca Exchange
and by connecting LE Ziri and LE Sorica with a radio-relay link. Between this
two stations there was no line of sight. The direct connection was prevented
by Crni vrh nad Cerknim mountain. This mountain was in the straight line between
the LE Ziri and LE Sorica. Because of the inconvenient angles the application of
passive repeater was unfeasible. In order to establish this connection, the investor
decided to apply radio-relay system SparkWave 18 and active repeater SparkWave 18AR
produced by Iskra Transmission.
The link between LE Sorica and LE Ziri was set up by SparkWave 18
and SparkWave 18AR active repeater. Active repeater was installed in Crni vrh
nad Cerknim mountain (altitude of 1250 m). The overall section length is 20 km.
Active repeater presented the most convenient solution for this link. The path
was shaded in the line between terminal stations, so the use of passive repeater
was not possible. The active repeater is next to the upper station of the cable
railway; nevertheless power supply autonomy was assured. Solar panel and batteries
supply the repeater. The life period of solar cells is more than 20 years.
Batteries assure 30 days of autonomy even in the case of damage of solar cells
or continuous shading. Normal daylight without sun is enough to supply the device
and for charging up the batteries.