In article <email@example.com>, AES
> Pointers to info on how XM and Sirius systems work, specifically as
> regards authorization?
[[.. munch ..]]
> Bottom line: Do individual radios actually talk back to the satellites
> at any point? Or do authorization and other command signals flow only
> from the satellites to the radio?
It is a *one*way* transmission, from the head end to the radio.
The transmitted code contains an "expiration date". if you don't get
a new code by the expiration date, the receiver stops playing.
The system designers _aren't_ "stupid", you know. <grin>
This basic authentication technology is _at_least_ 20-25 years old.
There was 'broadcast' radio (FM 'SCA' sub-carrier) transmission of
stock-market quotes back in the early 80's, if not earlier, that worked
in this precise manner.
I'm not sure, but I think some Muzak(tm) (and/or competitors) background
sound systems worked the same way.
Re: PAT's stories about gas customer woes -- the "2nd meter" party can
simply file a complaint with the state regulators. As a 'public utility',
the gas company is *required* to provide service to anybody 'willing and
able' to pay for it. The problem in the company infrastructure is *not*
a valid reason for cutting off the '2nd meter' customer service. They
can use their 'right-of-way' easement to dig up the piping, and cut off
the non-paying customer, and restore service to the customer in good
standing. *OR* run a new feed-pipe for him. This is the _UTILITY_
_COMPANY's_ problem, and *they* have to "do whatever is necessary" to
This is a situation where the customer can play hardball with the
utility, *and*win*. "No, I'm not going to do _your_job_ for you. NO,
I'm not going to 'be patient'. Get it fixed. *NOW*. " etc. "Breach
of franchise contract" is a _wonderfully_ potent phrase. The risk of
lawsuit damage awards is even more potent. As well as a 'negotiating
point' for demanding non-trivial credits for the the 'mistaken'
[TELECOM Digest Editor's Note: The state regulatory commissions are
pretty much, however, on the side of the utilties on things like
this. If you appeal to the regulators (informally at first, by
speaking on the telephone to the regulator's secretary or clerk) time
and again that person will **assume** at first there is more to the
story than what you have told him. He will take all the details, he
will relay all those details to the gas/electric/telephone company
involved; the utility will respond politely they will be glad to cure
the problem; the regulator's secretary or clerk will close the file
and get back to you saying "I have spoken to (the secretary or clerk)
of the utility's chairman and they assured me it will be promptly
taken care of." Then he will happily hang up his phone and go back to
sleep or his lunch or whatever, feeling assured he has helped another
customer recieve satisfaction. One big expenses at any utility are the
costs of 'doing business' with the state commission; the country club
memberships, the liquor and food tabs, etc. In many small towns, the
commissioners belong to the same clubs, churches, civic organizations,
etc as the utility brass. The utility says to the commission "that
request is unrealistic; we are not set up to do that" and that, as
'they' say, is that. Sometimes the state commission will even assist
the utility in bullying and humiliating the customer, to get the
customer to lay down and be quiet.
Now if *you* are in a position to file a *formal* complaint, engage
the services of an attorney who is licensed and competent to practice
before the commission, then be our guest. Most of us are not thus
equipped. Commmissions, per se, very rarely talk back to big business
per se. Big business runs things, unless/until it just gets to be
too outrageous for even the rotten commissioners to stomach.
Speaking of big business, you may have heard that Walmart got sued
as a class action about a month ago by several state attornies general
on violations of the (fairly uniform) Child Labor Laws. You are not
supposed to have children without majority age (18-21 most places)
operate 'dangerous machinery', i.e. chainsaws, etc even if all they
are doing is attempting to sell the 'dangerous machinery'. Walmart had
been saying 'nuts to that regulation' and telling their youthful
clerks to demonstrate all sorts of hardware and gasoline powered
equipment. Walmart pleaded guilty in late January, and agreed to
pay a fine totaling several hundred thousand dollars, on *one condition*:
There was not to be any news releases on it until after the fine had
been paid (from Bentonville corporate) and the fine got paid sometime
this past week. You can see the full story on line here in the
Telecom Digest Extra pages: http://telecom-digest.org/td-extra either
in the FeedSweep pages or the nytimes.html section. Just look for
the Walmart story.
So, get your lawyer and sue the gas company if it makes you feel