Viestikallio Fiber Networks

viestikallio-fiber.pdf

Viestikallio fiber network has multiple functions:

• Galvanically isolate datasystems at different buildings.
  (AC feed overvoltage protection is separate story.)
• Optically distribute reference signals
  • Stable frequencies (10 MHz, 100 MHz?)
  • PPS pulses ?

The Viestikallio Fiber Network is a Work in Progress thing:

The Monument Hut will likely need repairs before the protective PVC pipe is installed there.

Initial thoughts about fiber network use:

Data network:

• Ethernet network 10/100 Mbit/s on MM fiber

Frequency reference network:

• Frequency reference (10 MHz) AM transfer via passive optical distribution into optical receiver boxes at each building.
• Optional: Frequency reference (100 MHz) AM transfer via passive optical distribution into optical receiver boxes at each building.
• Optional: PPS AM transfer via passive optical distribution into optical receiver boxes at each building.
• Optional: Time-code AM transfer via passive optical distribution into optical receiver boxes at each building.

The frequency reference network is possibly doable by using only one fiber, and not separate fibers for each signal.

The frequency reference network is doable with optical splitters by which the signal is distributed without active devices:

• Sauna/Office: A 50/50 splitter (20% + 20%)
  • Reference for the observatory galvanically separate from the office reference.
• Radio: A 40/60 splitter (40% to sauna/office)
• Low cabinet: A 70/30 splitter (18% into the low cabinet)
• GSM site: A 50/50 splitter, 21% into local, and 21% into Monument.

...