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.
"Automatically."
The system designers _aren't_ "stupid", you know.
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 fix it.
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' cut-off.
[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:
So, get your lawyer and sue the gas company if it makes you feel better. PAT]