A family member worked at a military base served by a PBX and we never had any problems. I visited the switchboard room and it was very professional. There were no reports of problems calling other installations.
They used Autovon regularly, but just as a national dialing method via regular phones.
Even big business embraced Centrex like services. When I worked for Ernst & Young the entire New England region was dialable with 4 digits.
_Very_ iffy. The handshake is longer than the typical duration of any of those events involving a moving element.
Further, it would have 'auto-corrected' at the next self-id interval, a matter of a few minutes only. Again, this would have shown in the telco logs, a jump from one tower to a 'distant' one, for _one_ polling interval, followed by a jump back to the original (or one nearby) tower. Two discontinuities on adjacent intervals, and you know there's something funny going on. :)
That simply _isn't_ an issue on the common/shared 'control' channel.
If that phone was _making_ or _receiving_ a call, that is accurate. and I already discussed that situation in the original response.
As far as the control channel goes, that kind of congestion just doesn't happen. Sub-millisecond messages, with circa 100 seconds between repeats, and you can manage 100,000-plus phones from a single tower. Can't do nearly that many calls, but except in _very_ rare situations, not everybody is 'on' the phone at the same time.
I'd regard a _single_ report with suspicion, too. OTOH, if I have a _string_ of such reports, showing spacial consistency -- especially if the target was _in_motion_ -- I would tend to give it considerable credence.
I can't speak to the situation for the Australian case cited, but contemporary U.S. cell systems -- where the phone is -not- GPS equipped -- use *triangulation* from multiple towers to get a fairly precise (i.e., very close to as good as un-augmented GPS) position. That methodology is _very_ difficult to fool by freak events. Especially as the number of towers that report the signal increases.
One service the old Bell System provided for large subscribers was a national private switchable network for the organization; something more sophisticated than mere tie-lines. A person in one location could dial direct to anyone in another location. There were various names, one was "SCAN", though I don't recall what it stood for.
***** Moderator's Note *****I would just *love* to have been a fly on _that_ wall! Imaging the accountants from Ernst & Young sitting across the table from the Bell Labs statisticians, debating the value of a network that deprived AT&T of lots of long distance revenue at the same time it guaranteed that EY employees could dial more quickly.
I bet that got into a food fight during the argument over hookswitch-to-shoulder intervals and their relevance to the net aggregate dial interval differential. ;-)
Bill Horne Moderator
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