Asynchronous Pulsed Radiated Incident Light communications

A naturally occurring form of meshed free space optical communications is now being considered as a model for "community" networking systems. Operating in the nanometer wavelengths far above the regulated spectrum, this transmission scheme is inherently license free, apparently not monetized as of yet, and requires only miniscule amounts of energy.

The protocol is Asynchronous Pulsed Radiated Incident Light communications. It falls into the category of UNB or Ultra Narrow Band modulation with a bit rate of only a few bps directly pulsing the lightwave emitter. While free-space optics (FSO) offer much higher bandwidths for extending networks between buildings over roadways and rivers, FSO technology is a point to point medium. Any meshing of network nodes requires multiple optical transceivers. Beyond a simple line of site cable replacement, system complexity and cost increases exponentially.

What's been needed to make optical mesh networks practical is a means whereby all nodes are within a direct line of sight from each other in three dimensions. Consider it a spherical communications space. Within that space, local network nodes self-organize much like Bluetooth networks. Each local net is known as a swarm. The swarm will stay locked in asynchronous communication as units join or leave the group.

The low signaling rate has the advantage of needing only a minimum amount of processing power and is highly immune to noise and interference. The individual pulsating yellow-orange light emitters are easy to track and distinguish within the swarm. Security coding is by mutual assent of the communicators, since any intruders can readily monitor all transmissions.

The IEEE has wasted no time in beginning the standardization process, designating the Asynchronous Pulsed Radiated Incident Light communications protocol with the name FiFli and establishing a FiFli forum to work out the details of 802.something-or-other. The initial standards draft will be designated as APRIL-1 although committee activity is so intense that there are expected to be 30 distinct APRIL versions this month. Two subcommittees representing competing manufacturers are currently locked in a debate over what to name the signaling metric. One is pushing for "Natural Optical Wavelength Access Yield." The other wants the simplified designator "Wavelength Access Yield." It is expected that the NOWAY / WAY debate will be raging for some time.

Several illustrations of FiFli technology are available through T1 Rex. The first shows scientists investigating the optical emitter characteristics. The second shows a small FiFli swarm communicating within the lab environment. The third is an artist's conception of how FiFli would function as an open standard free of commercialization.


T1 Rex's Business Telecom Explainer offers easy to understand information about complex telecommunications and networking technology. T1 Rex explains how T1 lines work, VoIP telephone, PBX, virtual private networks, digital audio transport, Wi-Fi & WiMax, fiber optic carriers and other business telecom services.

John Shepler has been a published writer for over 30 years. With a background in electronics engineering technology, he has worked in a variety of industries including radio broadcast, aerospace and manufacturing. Involved in telecommunications since 1998, he combines his interests in writing and technology with and T1 Rex's Business Telecom Explainer.

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This was first published in April 2005

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