[time-nuts] Cell Phone time ?

Mike Feher mfeher at eozinc.com
Sun Nov 25 19:17:36 EST 2007

Well, this may seem like a dumb question to some of you, but, it does have
me baffled a little. I have noticed some time ago that the time indicated on
my cell phone is usually two to four seconds ahead of GPS time. I was under
the impressions that most towers did use GPS time. Anyway, I wrote it off to
thinking that the phone is free running unless connected to a call and hence
the drift. I even tried this theory by dialing my cell phone from my land
line, and low and behold, the times matched with GPS as long as I was
connected. Soon as I disconnected it was immediately off 4 seconds and
eventually settled at about 2 seconds. Since there is a signal indicator on
the cell phone that is active all of the time, it is obviously receiving
something from a local tower. Could that signal not have GPS time embedded
in it? It must have some, since going from one time zone to the other
switches the cell phone time automatically, but obviously not accurately. It
seems like a 2 second window is pretty large to search to make all of those
bits line up so one can talk, or to even have the phone ring. Thanks for any
help in making me understand this small dilemma. Regards - Mike 

Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731

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