I know it is not always true of analog basestations but, surely, all digital modulation
basestations use a GPS receiver to at least derive an input for the PLL circuits?
But do they use the GPS signals for time-of-day indication? I have to ask because my cellular phone does not show the correct time. It is not as if is not power-cycled: it is usually turned on once a day (Monday through Friday during school term) so the power has been recycled over one hundred times this year, so far. (Anybody who doesn’t know my opinions about cell phones will think I am joking about my phone use. I am not.)
I can find nothing in any blog on cellular phones about this problem, and don’t ask me to look in the product manual: I have no idea where it is, and I know nothing more about my phone beyond the base functionality of receiving and sending a call.
So, maybe the carriers just use a regular old-fashioned digital clock to derive time-of-day? Maybe they do...but that kind of confuses my understanding about how you can smoothly move from cell-to-cell. Making use of the capabilities that are
available, police forces are employing cell phone log information in criminal prosecutions, based on call times, to show that a phone was being used at the time of an accident. This has already
started in the UK, with police checking call records after accidents.
The evidence certainly seems to be in that cellular phone use really does cause
accidents, with driver performance being compared to driving while impaired through alcohol. But suppose the logs are not right in time terms. What use are they ? Surely, they will be challenged by defense attorneys?
But the situation is even more strange. My Samsung cell phone has displayed a time that is three minutes ahead of real time. That was during the winter. Come daylight savings time it is now fifty-three minutes slow – in other words, it didn’t take any notice of the time change.
My spouse’s Nokia phone displays the correct time.
And my daughter’s Motorola phone displays a time that is one hour and fifty-three minutes slow (it is also 15 days behind on the date).
These three different times are on the same network in the same cell.
Can a reader enlighten me with a sensible reason as to why these fundamental errors are occurring? Or is there an invisible Nokia time gremlin that has found a way of eating into competitive products?
