Ronja Twibright Labs

Backup connectivity

Ronja is an optical datalink 10Mbps full duplex over 1.4km:
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Connecting student dormitory

In 2002, students at the dormitory Mladost of Slovak Technical University in Bratislava, Slovakia, decided to replace old microwave link that was making them unhappy with Ronja. They used the building guide to build the device themself. After it, they installed it on their dormitory, and other end 940m away on the backbone.

1000 students were suddenly connected with 10Mbps full duplex connectivity to the backbone with almost zero roundtrip. They were happy with the device, because the Internet connection was running smoothly even when the bandwidth was exhausted to 100% of available maximum. The microwave was left there only as backup.

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Harsh winter conditions occured, where everything was covered with ice. The 940m optical link was still running.

From the traffic graphs it could be read that load of all the students resulted in 3-hour periods where the link was running continuously at 100% of its maximum. This didn't have any effect of the quality of the Internet access. For example, ssh still runs smoothly even in such a case, because roundtrip buildup doesn't occur on the device, as compared to half-duplex devices.



Ronja has distinctive aspect that make it suitable for campus networks:

  • There is a guide how to build it. Ronja is cheap to build and students can excersise their hacker attitude on it.
  • The used spectrum (light) is unregulated, so formalities fall off.
  • Some capus networks still are not wired up with fiber optics, or the usage policy of the owner of the network may be too restrictive to be accepted by liberal-thinking students. With Ronja, they can hook up easily their own optical infrastructure without property issues.
An expected information missing here?