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That actually helps explain an issue I had with my Galaxy Nexus. I worked in an area with spotty coverage, and it was extremely common that it would say I have
by kop316 8y ago
That actually helps explain an issue I had with my Galaxy Nexus. I worked in an area with spotty coverage, and it was extremely common that it would say I have full service coverage, only to have it drop to almost or no signal as soon as I used it to call. That issue was infuriating.
- giancarlostoro 8y agoI noticed this about phones, if you're using GPS and get a call and answer, guess what, no more GPS. So my guess is the phone cuts off the mobile data, and yeah then you'd see the real coverage.
- ajdhsjakafjt 8y agoMobile networks are two-way systems. If you have perfect reception of the mobile network - let's say full bars! - then that doesn't mean the mobile network also has reception of your mobile device. Most of the time, your phone is in RX-only mode to save battery. It listenes for incoming data every millisecond or two, but no more. But as soon as you actively use the network, things change. The basestation must receive your signals as well. This may suddenly and dramatically change the perception of "signal quality". Before it's RX quality only, then it's RX+TX quality. With incoming or outgoing calls, your phone may switch to another technology. While it may be idling in 4G, large parts of the world rely on 2G for voice calls. As soon as the call starts, the phone switched to 2G and naturally shows 2G reception.
- giancarlostoro 8y agoInteresting, yeah I don't know a whole lot about the underlying tech. I figure Google Maps uses my mobile data which explains why it sorta appears to have lost it's own darn mind.
- gsich 8y agoGPS is receive only, no mobile data is used there.
- rzzzt 8y agoAssisted GPS might require data/mobile network connection for the brief period of time the phone figures out where it is, roughly.
- bayindirh 8y agoAssisted GPS talks with the towers around, pings them for distance and gets their coordinates. It's happening on the GSM layer. It's also a no-data exchange IIRC.
- gsich 8y agoNo, I think it's only downloading almanach data for faster GPS.
- bayindirh 8y agoIt's one of the operational modes. On the other mode it calculates the location on behalf of the user and responds back with it [0]. In both modes data connection is required, so I'm mistaken. [0]: https://en.wikipedia.org/wiki/Assisted_GPS https://en.wikipedia.org/wiki/Assisted_GPS
- giancarlostoro 8y agoGoogle Maps uses mobile data to render the maps though do they not?
- gsich 8y agoBut how is this related to GPS?
- cbhl 8y agoCDMA phones (notably, 3G Sprint US, 3G Bell Canada, 3G Telus Canada) couldn't simultaneously use data (say, Google Maps) and voice. GPS lat/long would work fine, but you won't be able to download turn-by-turn directions or map tiles/vectors from Google. LTE (and 3G HSPA, such as AT&T, T-mo, 3G/4G/LTE Rogers Canada, LTE Bell Canada, LTE Telus Canada) don't have this behavior. Voice calls are packet switched (so you can do voice and data at the same time).
- izacus 8y agoThat can also happen if the phone switches between network types when calling - e.g. for a long time you couldn't call over LTE, so your phone switched to UMTS (3G) or GSM (2G) network to make and receive phone calls. So you could have excellent service for data and still lose signal for calls.
- kop316 8y agoThat makes sense too. I thought that also at that time that LTE was relatively new, so in theory, the UMTS or GSM would have a stronger signal than LTE, which would have meant my calls would be fine.