The Particle devices work well for 2) and 3). For 1) you’ll have to find an accurate GPS sensor that can operate indoors. What kind of environment/accuracy are we talking about here?
@Moors7: Thanks for the answer. regarding your question: Environment: indoors (inside a building) where GPS signal is limit/unreliable, but GSM signal is available/reliable. Accuracy: range of 5 feet of error margin.
@mchafik, you should do a google search. Interior position systems can be expensive and are typically based on beacons with known locations which are used to triangulate actual position. These beacons can be bluetooth, wifi or other radios designed for optimal triangulation. There are also hybrid systems that use IMUs (Inertial Measurement Unit) or other non-radio devices to gain further accuracy beyond radio triangulation.
Theoretically, the mesh devices could be used to triangulate the position of one from the known positions of 3 fixed base stations and using the RSSI of the signals. We are a long way away from any sort of out-of-the-box solution using Particle devices. The newer Nordic devices (the manufacturer of the IC that powers the Mesh/Gen3 devices) use a technology that enabled much more accurate measurement of the angle of receipt of a signal and thus can position quite accurately indoors. I have seen a beacon solution from a company called Wirepas (Finnish based and using Nordic semiconductors) - the idea is to use within a warehouse to track pallets to within a few metres.
On Particle 3G and LTE cellular devices, cellular positioning is limited to single tower positioning so the radius of uncertainty is typically 10000 meters.
@rickkas7: since Particle uses u-blox (Boron LTE for example comes w/ SARA-R4) and since u-blox offers the CellLocate feature. Is there a way to access that feature programmatically ? Thank you.