osewalrus (osewalrus) wrote,

Spectrum, Positive Train Control, and Philadelphia

So now everyone has heard about a thing called "Positive Train Control" (PTC) that could have helped avert the accident in Philadelphia.

To my considerable annoyance, the freight train guys and Amtrak are trying to leverage this into getting the allocation in 220 MHz that they DO  NOT NEED for PTC.

Mostly for my own reference, I'm parking a bunch of links to the FCC docket, WT Docket No. 11-79, on PTC for when I need to blog on this. But the PTC docket is a nice summary of both how hard it is to move away from the now outmoded "command and control" specialized allocation system to the actually sustainable system of open use and flexible use spectrum.

And if this MUST be a special service allocation, then let them share the open 700 MHz public safety allocation.

So first the FCC puts out a public notice (PN) to assess the needs and technical requirements for spectrum. Specifically, do they need a special allocation, or does existing spectrum (through secondary markets or other means -- they sadly were not looking at open spectrum in 2011, even though they should have even then).

PN: http://apps.fcc.gov/ecfs/document/view?id=7021448254

The train industry and vendors already using 220 MHz show up to explain how important PTC is and why the FCC needs to give them what they want, but actually does not provide any useful information whatsoever from a technical perspective on how PTC operates, what throughput it needs, how much data the system needs to handle, power levels, etc. The suggested technical rules -- the extent they are offered -- assume simply taking over the enitre band as currently constituted.


Existing band users, their vendors, and neighboring spectrum users weigh in with concerns.

Neighboring DTV broadcasters: http://apps.fcc.gov/ecfs/document/view?id=7021691743




A vendor with a different technology solution and different spectrum shows up to oppose the 220 MHz approach.



IEEE forms neutral working group. No one cares.

Interested parties get members of Congress to weigh in.

FCC responds by explaing to parties that (a) no one has actually answered the question asked, which is how would PTC work and what are the actual spectrum needs; (b) based on what info they do have, it appears that PTC can work with existing spectrum allocations and spectrum available in the secondary market; and (c) The FCC will work with the industry to expedite their need and make this happen, but please work with us guys -- or at least provide us technical information that goes beyond "we wants it precious! Give the spectrum to Smeagol!"


Vendors respond by repeating how wonderfully awesome a 220 MHz service for PTC would be, how challenging PTC is for the industry, how grant of the allocation would make their lives so much easier, and how this will save lives an stuff. Still no actual technical information that would the FCC actually make a decision on a service allocation or service rules.


Rival vendor responds with why their solution is totally not necessary, how they have failed to prove case, and how his technical solution on other spectrum is more than adequate to meet needs of PTC, which are still not actually defined.

Which is why, as the people who were lobbying for a 220 MHz PTC allocation will tell you, the accident in Philadelphia is all the fault of the FCC.

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