Wi-Fi GPS

When you use Wi-Fi only iPad, do you noticed that the LBS applications can sensor the location you are. There isn’t GPS hardware in Wi-Fi only iPad or Android tablets. Why do they still find where we are? They are using Wi-Fi GPS!

In traditional GPS, devices scan GPS satellites in sky and calculate current location. For Wi-Fi GPS, devices scan Wi-Fi APs, send the APs’ MAC address to Apple and Google, to inquiry those APs’ location. When they get APs’ location, they also get themselves’. Very simple, isn’t it?

Then, here comes a question. How Apple and Google know those APs’ exact location?

Because they have tremendous agents!

Yes, every iPhone or Android phone is a GPS agent.

When an iPhone scan an AP, it get AP’s MAC address first, then use phone’s build-in GPS to get current exact latitude and longitude. After that, the iPhone sends the information to Apple anonymously.

Apple collects the information to build a tremendous “World AP location Table”. Google alos does this in same way.

When a Wi-Fi only iPad scan the AP, it sends the AP’s MAC address to apple to ask location. Apple query it in its big table and give the result. Simple, but effective.

That means a Wi-Fi only iPad can still enjoy much convenient which a GPS brings, like many LBS applications.

Will you still like to spend $200 more on a 3G iPad?