The first of GPS receivers were much simpler than the current, they provide only the latitude and longitude, the rest was for the user, I needed to calculate the location on the map. The next generation has simplified maps, displayed on monochrome screens, but with the evolution of controllers and the fall in prices on color screens, flash memory and other components, they developed rapidly, until the model we have today.

The models combine current location with the coordinates of the 3D digital maps and software that calculates the position on the map, giving directions and voice guidance. Although the signal emitted by the GPS satellites is available for those who want to use, manufacturers of devices offer additional services such as traffic information (obtained using a data connection), updates the maps and so on, usually charging a monthly fee or by annual subscription.

We can say that 25% of the cost of a GPS unit for current is the basic circuits which calculate the coordinates, 50% correspond to other components of the hardware (processor, memory, screen, etc.). And the other 25%, the software and additional services.

With the miniaturization of components, has to make sense to include GPS receivers in smartphones, using the screen, processor, memory and other components. Chipsets current as Navilink NL5350 (used in N95 and other models of Nokia) combine the GPS receiver, the signal processor and a small amount of memory used by him in an incredibly compact packaging, which adds little to the weight and volume of unit. There are also modules that combine the circuitry of the GSM network with the circuits of GPS, providing a more integrated solution, as the XT55-GSC3 (to direct):

The first devices with integrated GPS were very expensive, sometimes costing more than buying a smartphone and a separate GPS navigator. However, with the passing time, prices dropped to the point of GPS integrated spend little to add to the final cost of the device and become standard in more expensive devices. With this, is missing only buy support for the panel, so you can use the smartphone as your browser:

Although the screen is smaller and the whole is less practical to use than an automotive GPS, the smartphone has an advantage, that is the fact you can always load it, avoiding the risk of theft by leaving the GPS in the car. Even without GPS integrated devices (like the photo 6120c) can play the role of browsers with the help of an external GPS receiver, connected via Bluetooth. An accessory more accessible.

Anyway, there are differences between different models of receivers. Initially, the main feature was the number ofchannels supported. The first receivers support only 4 channels (the exact number required to calculate the 3D coordinates), but soon came models with 5, 6, 8, 12, 16, 20, 32 or even 54 channels, creating an arms race similar to that existed at the time of the multimedia kits.

The number of channels of the receiver determines how many satellites it can monitor simultaneously. Most current models offer 12 to 20 channels, which is more than enough, considering that most of the time, only 9 or 10 satellites are visible and only 4 are needed to calculate the 3D position.

The spare channels allow the receiver to track the signal of more satellites and the use to calibrate the position, slightly improving the accuracy. However, the limit "physical" is still the number of visible satellites, which currently is never more than 12 in any part of the world. Therefore, from 12 channels is no longer any difference if the receiver supports 20, 32 or 500 channels, as only 12 will be used.

Therefore, the differentials have been the sensitivity of reception, size, weight and autonomy of the batteries (in case of Bluetooth receivers) or navigation software, the screen size, ergonomics and the available maps (for browsers) without speak on the issue of price, which has always been one of the arguments are most convincing.