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RONJA

This article is about Reasonable Optical Near Joint Access. For other topics, see ronja (disambiguation).
Single high-brightness LED with a cheap loupe lens creates a bright narrow[1] beam that can stream DVD-quality video over neighbourhoods. A few steps aside and the narrow beam becomes invisible.
Twibright Ronja with 130-millimetre (5.1 in) diameter lenses, operating on a 1,205-metre (1,318 yd) link using visible red light, max. range 1,300 metres (1,400 yd), with HPWT-BD00-E4000 transmit LED. Installed on a rooftop, with its user, in Czech Republic.[2][3]
Three bolts preloaded with pink rubber blocks facilitate fine adjustment of the optical head direction with a gear ratio 1:300.[1] The bolt on the right side is a part of a rough adjustment mechanism which allows pointing the optical head in virtually any direction.
Artificially enhanced picture of a situation where a Ronja link stops working because of heavy fog

RONJA (Reasonable Optical Near Joint Access) is a free-space optical communication system developed in the Czech Republic by Karel Kulhavý of Twibright Labs. Released in 2001. It transmits data wirelessly using beams of light. Ronja can be used to create a 10 Mbit/s full duplex Ethernet point-to-point link. It has been estimated that 1,000 to 2,000 links have been built worldwide.[4]

The basic configuration has a range of 1.4 km (0.87 mi). The device consists of a receiver and transmitter pipe (optical head) mounted on a sturdy adjustable holder. Two coaxial cables are used to connect the rooftop installation with a protocol translator installed in the house near a computer or switch. By doubling or tripling the transmitter pipe, the range can be extended to 1.9 km (1.2 mi).

Building instructions, blueprints, and schematics are published under the GNU Free Documentation License, with development using only free software tools. The author calls this level of freedom "User Controlled Technology".[5] Ronja is a project of Twibright Labs.

  1. ^ a b Cite error: The named reference rts_di was invoked but never defined (see the help page).
  2. ^ "154 Registered Installations of Ronja". ronja.twibright.com. Retrieved 3 June 2017.
  3. ^ "[1208] ronja/installations/czech/zdar_n_sazavou". images.twibright.com. Retrieved 3 June 2017.
  4. ^ Soderberg, J. (2010). "Free Space Optics in the Czech Wireless Community: Shedding Some Light on the Role of Normativity for User-Initiated Innovations". Science, Technology, & Human Values. 36 (4): 423–450. doi:10.1177/0162243910368398. S2CID 145786449.
  5. ^ "Ronja – BRL-CAD". brlcad.org. Retrieved 3 June 2017.

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Ronja Czech RONJA German RONJA Spanish RONJA (optinen tiedonsiirtotekniikka) Finnish RONJA French RONJA ID RONJA Japanese RONJA KM RONJA NB RONJA Portuguese

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