Re: [Cerowrt-devel] LCA 2018 talk available

[Mikael Abrahamsson <swmike@swm.pp.se>]

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On Thu, 15 Feb 2018, Joel Wirāmu Pauling wrote:

> If  POF (Plastic Optical Fibre) like install methods can be scaled up
> to Polymer/Glass runs (Sharpie knife slicing/jam into receptor). I
> don't see this being the problem. Depending on the Sheathing fibre is
> just as good as UTP cabling. Magnitudes cheaper too.
>
> When I learnt of POF I was excited, until I learned how it's severely
> limited in the bandwidth/frequency transmission department.
>
> I guess if we could get some sort of Clamp-on USB-C style adaptor for
> fibre would probably be the ideal. I don't really see why this
> couldn't work with MPO style fibre.

Problem with multimode fibers (that I imagine all above are) is that they 
have really low reach at higher speeds. So if your goal is to support 100G 
cheaply, I doubt the above will work very well.

Looking at:

http://ieeexplore.ieee.org/document/6192181/

"100G transmission over GI-POF is demonstrated by using 112-Gb/s 
PolMux-QPSK modulation and digital coherent detection. The transmission 
distance over 100m and simplified coupling method is suitable for optical 
data-center applications."

PolMux-QPSK is never going to be cheap'n'easy, it requires substantial 
amount of components and processing power at both ends of the fiber.

For cheap GI-POF 1000BASE-RH has been defined 
http://www.ieee802.org/3/GEPOFSG/email/pdfKiCuEsVuMv.pdf but it's only 
1GE. I doubt POF is a solution to your 10GE/100GE transmission speeds 
requirement.

So I think the conclusion basically is: 10GE and up is hard. There are 
real physical limitations here. I would be very happy if we could prove 
Shannon wrong. :P

https://en.wikipedia.org/wiki/Shannon%E2%80%93Hartley_theorem

-- 
Mikael Abrahamsson    email: swmike@swm.pp.se