Chapter 11

Using Maps

Your tablet is more than a laptop without a keyboard. Depending on the device, it’s also a map, compass, GPS navigation system, and a restaurant guide—all rolled into one.

There are a lot of apps that use maps; but in order to do so, those apps have to know where your tablet is. To that end, many Android tablets have GPS units, some have cell phone data, and all of them so far have Wi-Fi.

In general, tablets can be located by the following:

• GPS (global positioning satellites)
• Cell phone towers
• WPS (Wi-Fi positioning system)

There are more than 27 global positioning satellites orbiting the Earth. Your tablet’s GPS unit attempts to find the signal from at least three of them and triangulate your position. However, this requires your tablet to have a chip that detects GPS signals and be in an area that can detect them. If you’re indoors or around lots of tall buildings, your tablet might not pick up a GPS signal.

Your location can also be estimated using relative positions to cell phone towers. This isn’t as accurate as GPS because cell towers are positioned for efficient signal reception, not triangulation, so it’s less likely you’ll be in a spot with three overlapping points.

The third method of locating your phone comes from using a map of known public Wi-Fi spots. It’s a method that works well in urban areas and indoors—precisely the places where GPS does poorly. Because this approach requires only a Wi-Fi signal, it even works on laptops, netbooks, and tablets.

Depending on your hardware, your tablet may use a combination of all three methods to know where it is.

You can enable and disable your tablet’s ability to track you by opening the Settings panel and then choosing Location & security. Figure 11–1 shows the options available on a Wi-Fi Samsung Galaxy Tab 10.1.

Figure 11–1. Location & security options

You can choose to enable both the Use GPS satellites and Use wireless networks options. The latter option uses both Wi-Fi and cellular networks if your tablet is capable of this. You can also choose to enable or disable the Use location for Google Search option. You can disable this option if you have privacy concerns about Google tracking your location; however, enabling it gives you better results for local searches.