Get location (lat / long) without gps just like my google maps location function

Question

Get location (lat / long) without GPS, just like my location function on google maps. I have Google Maps on my mobile phone (Sony Ericsson G502 without GPS). It works great without GPS in India.

1. How does Google find my position?
2. When I look at cellid in the opencellid database, it has fewer entries for India. but google maps works fine on my mobile phone (India)
3.Is Google using an opencellid database or its own ?. if Google uses its own, we have access to the database


4. Is there any commercial cell database for India?

Answer 1

The answer is that cell phones use a variety of location methods, most of which were presented as part of an E-911 (Enhanced 911) or equivalent emergency service for other countries (like 999 in the UK) or since.

I do not know if GSM or CDMA has any localization protocols or standards outside of any E-911, and this is required. Therefore, I doubt that there is a common API for all mobile phones.

Localization of a mobile phone is carried out through:

• regular GPS
• Assisted GPS
• Cell Triangulation / Multilateration
• Cell (tower) identification (search for FCC / etc. Column database)
• Advanced Cell Identification (E-911)
• Uplink Profitability Difference (U-TDOA)
• Arrival Time (TOA)
• Arrival Angle (AOA)
• E-OTD (Extended Observed Time Difference)
• and / or a hybrid of these technologies and approaches.

(Src: Wikipedia / Mobile_phone_tracking )

These approaches are accurate and accurate from ~ 35 km (22 miles) to ~ 5-10 meters (16-32 feet) or better.

3.Is Google using an opencellid database or its own ?.

It looks like they have their own database without a publicly documented API.

4. Is there any commercial Cellid database for India?

I dont know.

Answer 2

Google almost certainly uses a proprietary database. They allow as much as:

This includes analyzing the Wi-Fi access points around you and your IP address of your computer and sending this information to a Google server, then to transfer it to a location that we can show on the map.

http://maps.google.com/support/bin/answer.py?hl=en&answer=153807

Google Street View cars are known to collect data on wireless access points that can be used in such a database.

Answer 3

Skyhook offers an API for geolocation of devices based on Cell ID, Wi-Fi access points and, if available, GPS. IPhone OS uses this to provide CoreLocation functionality.

They have SDKs available for most mobile and desktop OS. This is very good, but you will have to talk to them about licensing.

Answer 4

As other posters noted, Skyhook and Google maintain their own location databases for SSIDs and cell IDs. I believe that Geomena is trying to open an open database of localized identifiers, but it still does not have the breadth of coverage that patented competitors have. Google also provides a simple JavaScript client interface for IP geolocation (called ClientLocation), which can be reasonably accurate for some applications and there are a large number of IP geolocation databases.

If your application is web-based, you can use the W3C Geolocation API, which abstracts out specific geolocation technology and gives your website access to any geolocation method that the browser prefers to use. On iPhone, the Skyhook database is used to locate the phone using a mesh camera or a Wi-Fi or GPS location; Firefox uses the Google Location Service, which uses WiFi triangulation and refuses IP geolocation.

Using some level of abstraction (for example, the W3C API) can have real benefits if you want your application to run on different platforms that have their own location methods, if you want your application to degrade intelligently when only rough ones are available geolocation methods and you want your application to receive the benefits of additional accuracy, as your customers have upgraded to devices with GPS technology.