WiFi Location principle

Wi-Fi location and mobile phone base station positioning category, both need to collect WiFi locations information access point. In fact, WiFi is fantastic, it relies on the detection around all the wireless network base station (WiFi Access point) of the MAC address (similar to the format of 10-78-D2-93-58-C2), to the database of the MAC address coordinates, cross-linked set Location. This method is still required to have a network connection to do database query talent completed positioning.
The first to develop this technology is the Skyhook company. The principle of this technique is to take advantage of the following three facts: More and more WiFi hotspots (i.e., APS, or wireless routers). In the city more inclined to space no matter what point can receive at least one AP signal. (in the United States.) It is quite common to receive 3, 5 AP signals at each point.
China will also have more and more hot spots just to power up, no matter how it is encrypted. are bound to emit signals around them. A unique global ID for this hotspot is included in the signal. Even farther away from this hotspot. The connection could not be established. But it is still able to hear its existence.
Hot spots are generally very little variable position, more fixed.
In this way, the locating side simply listens to what hotspots are nearby, detects the signal strength of each hotspot, and sends this information to the Skyhook server. Based on this information, the server queries each hotspot for the coordinates recorded in the database, and the operation is performed. You can know the details of the client, and then tell the client the coordinates. Be able to think about. The more AP signals you receive, the more accurate the positioning will be. The principle is so simple. It's just that. A successful positioning requires two prerequisites: client can listen to the Internet to hear the coordinates of the hotspot in the Skyhook database has the first not to say, whether it is WiFi or edge, only to be able to connect to the Skyhook server.
The second is where the Skyhook database resides.
How does it know the coordinate information of each AP? There is a claim to be collected by the Netizen himself, and then sent to Skyhook,skyhook will pay the money.
But the official site is said to be driving around the streets. Set the AP signal while walking, and use the GPS to locate, thus have the coordinate information.
And they drive the data again and again on a regular basis to adapt to changes in hot spots.
The infrastructure is built on Google Street View cars.
In addition to taking the Street View, Google Street car has done two things
Collect all the public wireless MAC Address along the road, recorded with the latitude and longitude at that time.
But the database is bound to be out of date and need to be updated, when the world is using mobile devices + Google Locator program,
It's a matter of helping to do it unconsciously. The updated method is when WiFi is turned on at the same time as the phone's base station location or GPS location.
Handheld devices can be located in the mobile phone base station positioning or GPS positioning these two ways to obtain the current coordinates. and search the neighborhood via WiFi.
All MAC Address, in ... The Google repository is updated later.

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WiFi Location principle