I'd just like to ask for some clarifications regarding the GPS functionalities of android phones. When an application activates the GPS of a phone, will the phone need to be on a data plan or should activate the data traffic ( Settings > Wireless & Network settings > Mobile Networks > Data Traffic) for the GPS to get the phone's coordinates?
From Wikipdeia
The Global Positioning System (GPS) is a space-based satellite
navigation system that provides location and time information in all
weather, anywhere on or near the Earth, where there is an unobstructed
line of sight to four or more GPS satellites. It is maintained by the
United States government and is freely accessible to anyone with a GPS
receiver.
If you talk specifically about GPS then it's nothing to do with the data plan or even with your service provider. GPS is totally independent of it. Think of a stand alone GPS receiver device e.g. Garmin GPS 10. It just connects to your laptop through Bluetooth (some with USB cable) and start sending GPS data to it. These devices normally output GPS data in NMEA format. Modern phones includes same sort GPS receiver circuit integrated in them. The thing different here is that these phones consumes GPS data for internally available rather than directly outputting in raw form. That's how you get GPS location information in iPhone and Android smart phones. On the other hand think of GPS navigation devices we use in our cars e.g. Garmin nuvi. It shows the location of car on the integrated maps. There is no sim card in it. Same is with GPS fitness watches.
A good question here is How GPS calculates the location? Best explanation I found is on HowStuffWorks. It's very easy and very well explained. Apart form GPS there are other positioning systems in the world, though GPS is oldest and most widely used. After GPS from US, there is GLONASS from Russia. Some phones support GLONASS too e.g. iPhone 4S and Samsung Galaxy S III. Well there is nothing to worry for developers though. These phones internally use GPS and GLONASS to have high positional accuracy and gives the location in same way.
Other positioning systems includes Compass from China and Galileo. These are under development at the moment. For complete list check this Wikipedia article.
Edit: Location can be also be determined by mobile networks and wifi networks. For example Google Latitude tells your approximate location if you are connected with wifi and even you don't have GPS device connected. In case of location determination by mobile networks, the service provider may charge for location. Normally locations determined by mobile and wifi networks are not very accurate but location can be determined indoors which is a very big problem of GPS location calculation.
Hopefully it will help how things are working.
Cheers! :)
Atleast in India I can access use the GPS whenever I can see the sky, no data plan is required for me.
I haven't tried it on Android but it should be possible to get GPS co-ordinates without a data plan. My iPhone gets GPS locations even when out of reception, I can't see why android would be any different.
Related
Android is constantly changing. Currently, the Fused Location API is being used for location detection. But in my experience, without a Data connection, the GPS signal is not being found anymore.
How do I use the device's GPS only whenever there is no internet available?
Fused location provider uses a hybrid way to find gps using a variety of sensors, WIFI/data and the actual GPS chipset.
It will find the location COARSE/FINE accuracy is up to your case. It will just take a while longer than with the internet connection. If indoors or in an isolated area, it may very well take over a minute or two. Sometimes if the data signals just don't reach the device, yes it can fail.
It does work without WIFI or DATA in most cases.
Hi I am working on a project which requires fetching of user's current coordinates and I am fetching it in high accuracy mode.
Ever since I started testing out this application in my device I have noticed that my money is getting deducted from my balance I am not sure why is it happening.
I currently dont have a data pack and my mobile data is turned of in my device but I am connected to wifi. Even if some application is using internet for some purpose it should make use of the my wifi connection right?
Can anyone please explain me why is my balance getting deducted (if you have faced similar issue) ? Is it really because of the fetching of location in high accuracy mode ?
Thanks.
Edit
I get this dialog box frequently:
GPS coordinates on a android device (or any device for that matter) is received in 2 ways.
From a GPS hardware that connects to your GPS Satellites
From your network, via the GPS location of the tower to which your SIM card is connected to.
The GPS hardware connects to multiple satellites and approximates your location to a point. And this location is the most accurate you can get. It consumes a lot more battery and decipates a lot more heat on the devices, since a lot of current is needed to read from the GPS satellites. This does not use the network at all. If your SIM card cannot make phone calls/and/or/data even then this location can be received.
Your network GPS also does similar, but it takes GPS coordinates of the towers closeby (to which the SIM card is connected to, and then approximates the location of your device. This GPS location (in comparison with the GPS hardware) calculates a less accurate. This consumes GPRS/3G data bandwidth and you will be charged for this.
Both the hardware are completely independent.
Now, some smart ass developers in Google have used sensors like compass, rotation, movement to develop something called AGPS, which takes the GPS location from the GPS hardware, and then uses network and sensor information to ensure that your location is known without use of too much power, and there by lesser heat decipation. This is called AGPS.
I'm developing an app which fuses location from various providers, hoping it will give a more accurate location than if I simply used the Google API. However, the choice of providers would depend on the phone being indoor or outdoor (Network vs GPS, for example).
What is the best way to detect if the device is indoor or outdoor? My first thought would be using the Light sensor, and maybe cell signal strength and WiFi (if there are WiFi networks near, it's likely the device is indoor), but I don't know which weight/confidence I should attribute to these sensors.
Edit: this is for my masters thesis, in which the goal is to get the location from the different providers (GPS, Network and Passive) in the Android API, and fuse them with a formula. Depending on whether the phone is indoor or outdoor, the several locations would have different weights. There would also be parameters like if battery life is priority or not (I haven't developed this formula yet).
Just subscribe to both providers and use location.getProvider() and location.getAccuracy() when new location arrives--to check if it's more/less accurate then previous.
I'd say your best bet is the GPS signal itself, because GPS rarely penetrates buildings.
In built up areas, you'll encompass WiFi networks all over the shop.
So I am working on this app that will get the location of a wifi hotspot by just detecting it using the sensor wifi of the phone (The phone is not actually connecting to the hotspot wifi, it just detect).
I was doing some preliminary research before start developing the app, and it seems that the Google Geolocation API will do the work for me. However, it is not free (at least what I understood after reading through the API). I had checked other apps that detects wifi hotspot, and I am just wondering if those apps have their own database with all the wifi hotspot information (SSID, location coordinates, etc) so when the wifi sensor detects a wifi hotspot, it will lookup the database and get the information such as location.
Also, I was mentioned by a colleague that Google Maps also stores wifi info. Is is true? Cause I couldn't find any info about that.
Android has multiple LocationProviders, including:
LocationManager.GPS_PROVIDER : get position using GPS
LocationManager.NETWORK_PROVIDER : get position using Wifi, cell network, etc.
LocationManager.PASSIVE_PROVIDER: get position using data provided by already running providers. This allows several apps to share geolocation information)
You don't have to pay anything to use NETWORK_PROVIDER
Some providers might not be present on all devices, depending on phone model and android version.
Providers have different characteristics: NETWORK is fast but not always precise enough, GPS is precise but slow and battery intensive, etc. The best strategy is to request location from several providers, and cancel pending request as soon as you get a location that is good enough depending on your criteria (precision, response time, etc.)
I found this article by Reto Meier quite useful to wrap my head around geolocation on Android
I'm working in android (developing application for mobile and tablets). I am using android version is 2.2.
In my application, I want to capture the longtitude,latitude.
My suprevisor is said to me capture the locations using GPS,AGPS,LBS
I'm new to android .I does not know GPS,AGPS,LBS.
Please send me the details, what are the difference,advantages,disadvantages of these 3?
Don't compare LBS with GPS and AGPS. LBS stands for Location based services . It's a service done with the help of GPS/AGPS . For example 'Requesting the nearest business or service, such as an ATM or restaurant' is a service required by a user. There are many applications available for to provide above service. Those application will use either GPS/AGPS to find the location and service to user based on the location fetched.
So simply any application which use location to serve users are considered as LBS.
Following is the difference between GPS and AGPS
The difference between GPS and A-GPS is actually pretty straightforward. A GPS phone comes with a built-in GPS chip. GPS, short for Global Positioning System, is typically used to determine the location, speed, direction and time of the device. So, for example, in the case of the Mobile, when GPS is activated on the unit, the system would be able to triangulate the position of the receiver when three or more satellites are connected. And since it is able to calculate speed and direction, GPS is also commonly used as a navigation device while driving.
A-GPS (Assisted-GPS), on the other hand, was developed to enhance the performance of GPS. This is especially useful in environments where the GPS chip may have difficulty in getting a satellite signal, such as an urban canyon, or places where there is too much overhead obstruction. What A-GPS does is it leverages on an intermediary called an Assistant Server which provides information on cell ID or other data to help the device identify the right satellites to connect to. This shortens the time needed for a location lock although certain A-GPS solutions require an active connection to a cell phone network.
Pros and Cons of GPS and AGPS:
The realiability and Accuracy is high in the GPS and it is low in AGPS.
The location captured by AGPS is not as accurate as GPS.
The location capturing via GPS is time consuming and power (Battery) consuming, etc.
Hope it helps. For more details on A-GPS
GPS - Global positioning system -> get your location via satellites
AGPS - Assisted GPS -> get your location via satellites and network providers
LBS - Location Based Services -> doesn't have much to do with getting your location.
Basically, in Android you can get your location using following providers:
Network: get your location based on your wifi connection. fairly fast, but not so accurate
GPS: get your location based on GPS receiver. fairly slow, but quite accurate
so you have a trade-off: either to use Network provider and get your results fast, or to use GPS provider and get more accurate data.
Read more here:
http://developer.android.com/guide/topics/location/strategies.html
LBS - Location Based Services
GPS - Global Positioning System
AGPS - Assisted Global Positioning System
LBS
As abbas.aniefa said, We can't say differences of LBS over GPS and AGPS. It is the service which uses GPS/AGPS to find location. Android provides a number of building blocks for location based services.
GPS
GPS, the Global Positioning System run by the United States Military.
This provider determines location using satellites.
Depending on conditions, this provider may take a while to return a location fix.
Advantages
It will give our location accurately,
It will work fine in out-door locations.
Disadvantages
It may be very very slow in in-door locations,
It will quickly drain battery.
It will be slower than network provider.
A-GPS
A-GPS - Assited GPS. Normal GPS can take a long time to get a position fix. 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).
A-GPS will come under network location provider category because it uses GPS chip on device, as well as assistance from the network (cellular network) to provide a fast initial fix.
Advantages
It will give our location very accurately in-door location itself,
Drainage of battery will be saved,
It will be faster than GPS Provider.
Disadvantage
We can not use it with GPS alone. It will depend on network connection.
Over all Differences of GPS and A-GPS
GPS
Uses GPS chip on the device,
Line of sight to the satellites,
Need about 7 to get a fix,
Takes a long time to get a fix,
Doesn’t work around tall buildings.
A-GPS
Uses GPS chip on device, as well as assistance from the network (cellular network) to provide a fast initial fix,
Very low power consumption,
Very accurate,
Works without any line of sight to the sky,
Depends on carrier and phone supporting this (even if phone supports it, and network does not then this does not work).
I think GPS is done/processed via satellite communication without any network service provider.
The AGPS is done/processed via the network (which is provided by service provider such as Airtel,Vodafone,etc).We should pay for service provider for usage of network.
The LBS is processed through the AGPS.
I dont know whether my points are correct or not.Im heard from others and put it.
All are welcome to give their suggestions,ideas,etc.