Satellite Radio Authorization: How Does it Work?

Pointers to info on how XM and Sirius systems work, specifically as regards authorization?

When a satellite authorizes a given radio, does it do it by sending that radio (and, as a side effect, all other radios) some kind of digital key that combines with some unique built-in matching key in that particular radio to enable it to decode the broadcast content?

If so, presumably if you stop paying your bill it can also deauthorize your radio by sending something to wipe out the code?

But suppose you put your radio in a shielded box, stop paying, wait a few months until they give up trying to deauthorize you, then bring it back out -- are you still authorized? Or does every authorized radio have to get reauthorized at some periodic interval?

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?

(Not looking to play any games here -- just interested to understand how it works.)

[TELECOM Digest Editor's Note: An interesting problem, and one that the gas company deals with a lot in older inner city areas, which is gradually getting cured. Many years ago, gas was delivered in underground pipes (it still is), but as a matter of economics the gas company used a lot of 'branch lines' off the main feed. For example, there are two dwellings on a piece of land, one sort of behind the other one. Gas company runs a pipe which attaches to one meter, then the pipe 'branches' off and runs to the second meter. First meter owner gets delinquent in paying his gas bill, and refuses to allow access to his basement for the purpose of cutting off his service. Gas company keeps telling the man "let us in your basement so we can lock off your meter." Man refuses to do so, assuming there is no way for gas company to cut his service if they can't get in his basement. What the gas company will do is get a permit from the city to excavate in the street and cut him off at that point. The only trouble is, the person on the other end of the property, with his own meter, which is in good standing, winds up getting cut also.

Needless to say, that man (second meter) raises plenty of hell, and demands his gas service back. Gas company claims it was an accident, and they will turn him back on ASAP, but there is one big problem with natural gas which does not apply with other utilities; before they can turn him back on (with the consequential lighting of his pilot lights to prevent explosions, etc, now they *absolutely must* get the other guy's pilot light relighted as well (or in actual practice cut his meter) to avoid possible explosions at that end. So they turn one neighbor against the other one, telling second meter, "Gee, we would love to restore *your* service but we can't get into first meter and under the law, even if we should not have 'accidentally' cut off your service, we have to light his pilot as well (and all the other pilot lights on the same branch line)." You better believe second meter finds first meter (if he has to break the basement door down himself) and imposes on him to allow the meter to be cut off so that then gas company can turn the line back on, and go around lighting all the pilot lights for all the other residents on the 'branch line'.

Western Union also had similar woes with their clock service fifty or more years ago: a large office building, maybe there were a few dozen clocks on the circuit. Some joker would not pay his clock bill and assume WUTCO can't do anything about it if I don't let them in the office to remove the clock. Their policy was where an individual clock was on an individual circuit, WUTCO would put a 'load' on the line and just leave it there. Eventually the load would overcome the tension from the escapement spring and stop the pendulum from swinging, which had the effect of denying any more clock service. When the guy paid up, the clock man came back out and restarted the clock. But if (as was common) there were fifty clocks and only one setting-circuit handling them all; one joker does not pay and refuses to give up the clock; WUTCO had to shut them all down, then once they were all dead (due to the load on the line), go back and restart the 49 good customers and let the one bad guy sit there and stew in his juices.

Of course there are no clocks with WUTCO works in them any longer, and although gas company still now and then has to resort to cutting off many customers temporarily (and use *them* as tools to get after the bad guy) and delinquencies in paying for gas is more common these days for various economic reasons, gas company is gradually redoing their outside plant infrastructure, so that everyone gets their own direct feed to the gas main, so customers either voluntarily admit the gas man to inspect/lock out their meter for non-payment, or gas company excavates in the street as needed, but now there are no innocent victims in the process, or not as many as in the past.

My understanding is satellite receiving units do not 'talk back' to the satellite; everything is done from the satellite end, and as long as there is any 'unfinished business' with any one receiver, the satellite company just keeps on sending over and over the required codes. DISH has those little plastic 'smart cards' which have to be replaced once a year or so, so I assume if you were not paying, at best, you'd get the remainder of the time available before the Smart Card ran out. I do not know what some of the others are doing. PAT]

Reply to
Loading thread data ... Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.