I see that LocationManager.NETWORK_PROVIDER.getLastKnownLocation() returns the last location, but how is the location updated? If the GPS is disabled, will it entirely rely on BSSIDs detected by WiFi? What if the WiFi is also disabled? Does it take mobile service tower data into account?
Yes, the location service has basically three levels: GPS, WiFi, Cell tower.
GPS is used with the GPS_PROVIDER, and WiFi and cell tower go both into the NETWORK_PROVIDER bucket.
To quote the NETWORK_PROVIDER description:
This provider determines location based on availability of cell tower and WiFi access points. Results are retrieved by means of a network lookup.
Related
I have the target to obtain geolocation of mobile phone, for this purpose i use three approaches:
Wifi geolocation if wifi access points are present.
GPS if satellites are visible for mobile phone.
Geolocation by cell towers.
I use google location api for the retrieving location by cell towers ids and BSID's of routers.
But, I have problem in particular case - my mobile phone is outside the city and wifi points are not available (first item is not appropriate), gps location also is not eligible because mobile phone is in building and signal from satellites are not available), last variant with location by cells tower works, but result has very bad accuracy (from 100m to a few km).
How can I improve the accuracy to a few tens of meters?
Can i use number of mobile phone for obtaining location of mobile phone?
I want to fetch the location using google play services LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient); when GPS/Wifi is turned off. Reading the articles/blogs regarding FusedLocationApi, its mentioned that this API will provide the accurate location using any of GPS/Wifi or Cellular network. I am confused that if cellar network can provide the location then FusedLocationApi should return the location if Gps/Wifi is disabled but its returning null. Can anyone please let me help/guide to fetch offline location using cellular network.
Regards
You cannot get location using the cellular network through the standard API when GPS and WiFi location are disabled.
The device must have location enabled in order for an application to retrieve location. This is a basic permissions issue for the end user; if the end user requests that no location be available, then no location is available.
When retrieving location, there are two sources of information:
GPS: This uses satellites in space to locate the device. GPS provides the most accurate location, but is slow, especially if you do not have a data connection. On the device this is the "device only" mode.
Network: This uses WiFi and/or the cellular network. There is not a way to choose WiFi and cellular location separately. When you get a location update, the horizontal accuracy is a strong indicator of whether WiFi or the cellular network was used. WiFi accuracy should be in 10's of meters, while cellular will probably be 100's of meters. If you are in an area without WiFi coverage but with cellular coverage, then the network source will still provide location updates.
You can also use both these sources. This is the "high accuracy" location mode.
If you turn both of these off (disable location), then you will not get any location.
I am trying to get the user's current location using phonegap Geolocation api, which says "Common sources of location information include Global Positioning System (GPS) and location inferred from network signals such as IP address, RFID, WiFi and Bluetooth MAC addresses, and GSM/CDMA cell IDs". I am able to properly get the location when internet is ON (irrespective of the state of GPS).
Is there a way to get the location using triangulation when the internet is OFF or not accessible? (GPS might be ON or OFF)
A BIG "NO"! This is like cutting down hands and asking if I could clap now? GPS and NETWORK location providers are the only way to receive user device location.
For GPS location - you need GPS sensors to be ON.
And for NETWORK location you need to have internet connection ON, because in this case the location is calculated on the basis of Cell-Tower/Wifi-spot ID which is then sent to google servers (via internet) to fetch the location details of the respective Cell Tower or wifi spot. Google's location server have its own location approximation algorithms on the basis of which it tells your location.
So, there could be no way you could receive a location when both GPS and INTERNET are OFF.
Note: You can still get the last received location from any of these providers by using LocationManager's getLastKnownLocation() even when the providers are OFF. But this locations are usually outdated ones and are barely of any use.
{ enableHighAccuracy: true }
Enabling that option will allow the Android device to get the location even with the WIFI option disabled.
I'm using network provider for location updates. Do I need to to have internet on my cell?
Here is my code
LocationMngr = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
LocationMngr.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, inteval, 0, this);
I'm getting confused of seeing other's Answer. Then I searched a lot and get some idea about that. While searching only, I have learnt about new concept of A-GPS. I would like to share those things with you.
There are three location providers.
1. GPS Provider
2. Network Provider (AGPS, CellID, WiFi MACID)
3. Passive Provider.
Note: I refer this from this site. As you asked question related to network provider, I will share regarding to that.
Network provider, name itself says that it needs network connection. Refer this article. It need network or WIFI connection to proceed.
A-GPS
GPS on cell phones is a bit more murky. In general, it won't cost you anything to turn on the GPS in your cell phone, but when you get a location it usually involves the cell phone company in order to get it quickly with little signal, as well as get a location when the satellites aren't visible (since the gov't requires a fix even if the satellites aren't visible for emergency 911 purposes). It uses up some cellular bandwidth. This also means that for phones without a regular GPS receiver, you cannot use the GPS at all if you don't have cell phone service.
For this reason most cell phone companies have the GPS in the phone turned off except for emergency calls and for services they sell you (such as directions).
This particular kind of GPS is called Assisted GPS (AGPS).
Note: Even if phone supports it, and network does not then this does not work
No need for Internet for retrieving location (GPS or Network provider). Using Internet can speed up the process and giving you more accurate locations (when dealing with Network provider).
No, the GPS sensors are independent of connections to the internet, so you don't need to worry about internet connectivity if you just want to get your location via GPS. I have a Nexus 10 which has a GPS sensor, and it works just fine when I'm roaming without internet connectivitiy.
no you don't need internet conection.but in some roms it may be some errors in conection.
in gps module you don't need internet but some ways you can use wifi for more performance in.such as google navigation services.
What methods does Google use to match IP addresses to approximate location inside a building using wifi or service-provider?
The actual location identification method is abstracted away. Developers are to only concern themselves with the source.
The NETWORK_PROVIDER source uses the IP Address and Cellular triangulation to identify the user's location.
http://developer.android.com/reference/android/location/LocationManager.html#NETWORK_PROVIDER
Also the method getLastKnownLocation(best) that provides the LocationManager can be used, as GPS won't work indoors. It is not accurate, but it will give a location of a big area.