Re: Does the world need 5G? Driverless cars, IoT, future devices will demand it - Feature - TechRepublic

Posted by Steve Smith on
URL: http://friam.383.s1.nabble.com/Does-the-world-need-5G-Driverless-cars-IoT-future-devices-will-demand-it-Feature-TechRepublic-tp7585831p7585837.html

Marcus sed:

http://www.techrepublic.com/article/does-the-world-really-need-5g/?tag=nl.e099&s_cid=e099&ttag=e099&ftag=TREd8c0fa8

Cabling is insane for large supercomputer installations. 
Some systems have more than 50 miles of Infiniband cabling.   

http://scr3.golem.de/?d=1207/SuperMUC&a=93344&s=8

Would be great to just roll in the boxes and have them communicate (at
sufficient bandwidth) without wires.

Of course there *is* a good reason for having wires... each one is essentially a separate "aethereal universe".  


From the Cray2

http://upload.wikimedia.org/wikipedia/commons/thumb/1/1e/Cray-2-p1010252.jpg/1024px-Cray-2-p1010252.jpg

Each cable between the modules was a twisted pair, cut to a specific length in order to guarantee the signals arrived at precisely the right time and minimize electrical reflection. Each signal produced by the ECL circuitry was a differential pair, so the signals were balanced. This tended to make the demand on the power supply more constant and reduce switching noise. The load on the power supply was so evenly balanced that Cray boasted that the power supply was unregulated. To the power supply, the entire computer system looked like a simple resistor.

and this great anecdote I heard when I first came to LANL:2

The wiring and boards were assembled in Chippewa Falls, Wisconsin in the USA and key members of the manufacturing crew included women skilled in weaving and the other fabric arts. These women would work in teams to do the amazing job of wiring the backplane of this machine.

I'm working on a camera system that has 84 1080p30fps (raw) streams and the customer wants to know why we can't just run it over WiFi... he's seen 1080p over WiFi  after all!  (2Mp x 24b/p x 30 ~= 1.5Gbps/camera => 126Gbps  which (slightly) exceeds even the fastest 100GigE ethernet speeds.... so I guess "theoretically" we are in the regime of what current technology can multiplex...   The "current" prototype includes a bundle of 84 coax and 84 power wires... a non-trivial support system.

Maybe if someone can clone Tesla, he could pull it off?




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