When a map shows a blue dot, it is tempting to call the result 'GPS'. Modern Android location can be more complicated. The operating system may combine satellite observations with network and sensor information to produce a useful estimate.
GNSS is the broader term for satellite navigation systems, including GPS and other constellations. Satellite positioning can provide high-quality outdoor location without requiring the phone to be attached to a particular Wi-Fi network or mobile tower.
Its weaknesses are blocked sky visibility, reflections and the time needed to acquire a good fix.
A phone can observe nearby Wi-Fi networks and use known information about those access points as a location clue. This can be valuable indoors and in dense cities where satellite reception is poor.
The phone does not need to assume that the Wi-Fi router's public IP address equals its precise location; Wi-Fi positioning is based on observed radio environments and platform services.
Cell towers give a phone broad information about the network area it is using. Depending on network conditions and available measurements, cellular information can contribute to a coarse estimate.
It is generally not sensible to advertise 'cell tower location' as if every tower observation creates a precise street-level point.
Modern location providers combine available evidence and trade accuracy against power use. An app may ask for a certain quality of location rather than manually choosing one radio source forever.
This is one reason the source label in consumer apps can be misleading: a useful location may have been produced through several inputs.
A tracking app should record timestamps and, where available, accuracy information, tolerate temporary uncertainty and avoid pretending that every point is equally reliable.
If your route jumps around, continue with Why is my phone location wrong?. If battery life is the problem, read GPS tracking and battery optimization.
Imagine walking from an open park into a shopping centre and then onto an underground train. Outdoors, satellite measurements may dominate because the sky is visible. Inside the shopping centre, Wi-Fi observations and other platform data may become more useful. Underground, the phone may have very limited fresh positioning information and fall back to a coarse or recent estimate.
That transition is normal. A location provider is trying to offer the best answer available under changing radio conditions while managing battery use. The source that is most useful at 14:02 may be almost useless at 14:05.
For tracker users, the practical lesson is to judge a trail by context. Do not insist that every point must be 'pure GPS', and do not assume network-derived positions are worthless. What matters is whether the estimate is timely and accurate enough for the purpose.
Imagine walking from an open park into a shopping centre and then onto an underground train. Outdoors, satellite measurements may dominate because the sky is visible. Inside the shopping centre, Wi-Fi observations and other platform data can become more useful. Underground, the phone may temporarily have very little fresh positioning information at all.
That transition is normal. Android's location stack is trying to produce the best estimate available under changing radio conditions while also managing battery use. The source that is excellent at 14:02 may be poor at 14:05.
Satellite positioning is extremely useful, but refusing every network-derived clue would make phones slower and less capable indoors. Conversely, a coarse cellular estimate should not be marketed as if it were precise satellite GPS. Good tracking software treats the location as an estimate, records the time and accuracy information available, and lets the user interpret it in context.
If your route jumps after entering a building, that does not necessarily mean the app changed from a “good” technology to a “bad” one. It may simply be operating with less useful evidence.