Satellites and Embeddeds

greenspun.com : LUSENET : TimeBomb 2000 (Y2000) : One Thread

On the FCC Website is the latest report on the telecommunications industry. Notice that the FCC relies totally on the industry for information. I have read the part on satellites and I am curious as to how one remediates embedded chips in satellites.

http://www.fcc.gov/year2000/y2kcsr.html

Link

As usual, the format is PDF and I do not know how to copy it. Anyway, I will type a couple of sentences from the section Satellite and High Frequency Broadcast.

On the marked page scroll down to this heading (Pages 72-80 of the Y2K Communications Sector Report) PDF time.

Under the heading "Satellite Network" are a couple of interesting statements(amoung many others).

FROM THE REPORT

"Both earth and space stations(this is what they call satellites) may rely upon date-and time-sensitive systems and processes through electronic switches and clocks, most of which may require precise synchronization"

Also mentioned are phones etc. Hummmmm.

-- Mike Lang (webflier@erols.com), November 24, 1999

Answers

I too have often wondered how all the "experts" showed absolutely no concern for the satellite coms. Even the nuke plants are planning on using sat phones to keep in contact if y2k kills the regular phone system. But the thing is, how many sat's will have little problem? Any satellite experts out there that can answer this problem? Is it only the sat's launched in say the last 15 months that are y2k compliant? Or were somehow the sat engineers more smarter than the government and most other industries?

-- One Guy (wondering@y2kgi.com), November 25, 1999.

how does one remediate chips in satellites? Very carefully. Could be one hell of a tall ladder

-- Nancy (wellsnl@hotmail.com), November 25, 1999.

To all who were kind enough to keep their messages on my first thread here civil and on topic, Thank You. As a side note, I wish to exend my apologies for not responding to a few posts on that thread. In the midst of participating, I received word that my niece had delivered her second child, a daughter, Josephine, who was unfortunately stillborn. Have had funeral arrangements, etc, to attend to.

I hope my technical experience can shed some light on the topic of satellite communication operations.

As I noted in my thread on telco Central Offices, timing IS extremely crucial, and an extraordinary accuracy is required. The main trunk lines operate at GigaHertz transfer speeds. The only current source for world-wide synchronous timing at that accuracy is the GPS system.

ALL satellites utilize this same system for exactly the same reason - high accuracy, world-wide synchronous timing. The central clock for the GPS system resides at the National Institute of Standards and Technology Headquarters in Boulder CO. Should that clock glitch..... it is all over. Every communications system on the planet glitches along with it.

Satellites do not use an internal primary clock. All primary date/time/timing data is received from GPS, processed by an onboard secondary clock through a comparator circuit, then the 'corrected' output of the secondary clock is sent to a third 'working' clock which then finally feeds every elecrtronic circuit requiring a clock or timing pulse.

Accuracy is on the order of 1 x 10 exp -15 seconds (that is a thousandth of a billionth of a billionth of a second) simultaneously by every single satellite.

Hope this is not TOO techie an explanation.

btw: Happy Thanksgiving to all!

-- hiding in plain (sight@edge. of no-where), November 25, 1999.


Oops - that should be thousandth of a Millionth of a Millionth of a second ... apology!

brain still not fully y2k compliant! :-)

-- hiding in plain (sight@edge. of no-where), November 25, 1999.


What's a few billionths between friends?

-- counting down (the@days.now), November 25, 1999.


Prayers for your niece Hiding. Thanks for your explanation. Information like this helps me to understand.

Counting down - billionths of a second, not a lot of time to FOF. :)

-- Mike Lang (webflier@erols.com), November 25, 1999.


Moderation questions? read the FAQ