Let’s say a time machine was invented an I sent an iPhone 7 back in time 20 years. Let’s say it’s currently active on the AT&T or Verizon network. What functions would it maintain? Could someone use it to make a phone call? Would the GPS work? Would it display the appropriate time and date? Assume that the time travel itself doesn’t otherwise damage the phone, and that the person using it back in 1996 somehow knows how all the various functions are supposed to work.
20 years ago the US had very limited GSM capability. So no phone calls in most cities. One would need to check the precise bands supported to see if it would work in those countries that did have GSM. You would have trouble getting a SIM to fit, but it isn’t impossible one could cut one down to work. Your current SIM would not work. (After all, how would the network back then know who you were, and most importantly who to send the phone bill to if the account was not to be registered for another 20 years?) So the recipient would need to buy a new one and get a contract. And even then you would be looking at Europe, Australia, some Asian countries. Not Japan, not most of the USA, to get even a simple phone call or SMS to work.
Date and time might work, but depends upon whether the cell you were in was capable of telling you. No data capability, that was some time off. GPS should work. Cellular assist for navigation would not. GPS might take a while to cold start, but should be capable of working out where and when it is.
To add: This is based on my understanding that most of the CDMA networking the US used back then has gone, and iPhones don’t support the legacy protocols. GSM forms the base of the more modern protocols, and the fall back should continue to work, even though most carriers are merrily ripping out the basic GSM systems now.
General availability of GPS wasn’t made available for civilian use until 2000, so GPS would be of limited use in 1996.
GSM was available in 1996, but the actual GSM General Packet Radio Service (GPRS) wasn’t deployed until 2000, and since GPRS was the very first transport layer for mobile TCP/IP, the lack of it would mean that the iPad would have no data service at all.
No Wi-Fieither:
So. No data. No voice, since iPads don’t provide any non-IP voice communications. No electricity, unless you remembered to send the charger through the time machine as well.
If all else fails, it’d make a fine prop in a movie.
Who said anything about iPads?
Before May 2, 2000, Selective Availability was enabled in the GPS system. This means that deliberate random errors of up to about 100 meters were introduced for civilian GPS units. So in 1996, the iPhone GPS would still be functional, but the accuracy would not be as good as you see today.
–Mark
Also there was a rollover of the GPS datum on 21 August 1999. As iPhones were sold from 2007 presumably the software does not address the possibility of the phone existing before the rollover.
I did. I misread the OP. However, everything I said holds for an iPhone as well. Do you really think there’s a meaningful difference between them, except that an iPad doesn’t have mobile voice calling capability? 
None of the communications technologies any mobile smart device needs were available in 1996, unless our time-traveler also brought along a wired Ethernet dongle and can plug into someone’s 10base-T network.
Like I said, possible a nice prop.
It would be a good looking PDA, severely crippled by an almost complete lack of connectivity.
USB exists since 1996. But Apple quite thoroughly made most functions unusable without itunes.
no voice
no mobile data
no wifi
no way of moving data on or of the phone
The iPhone on it’s own isn’t really that big a deal. The infrastructure to do stuff with it…
The camera should be able to work just fine. A pocket-sized video recorder would seem like stuff out of science fiction.
Until someone wanted on the TV, just like a VCR does. In that case, our time traveler had also better have brought a Thunderbolt-to-video dongle with NTSC outputs. Which do exist, but aren’t normal equipment with an iPhone.
Likewise with nice snapshots. Those will be great until someone wants a print, because in 1996 that’s how we actually looked at and kept photos – emulsion on paper.
An iPhone 7? Probably not well, you’d need a 3.5mm headphone jack. flees
You could transfer data using WiFi…
Might have to wait a year or so, though…