Pre-installed soft
The navigation programme, originally installed in the navigator and sold with it, in other words, a set of maps available to the user “out of the box”.
Most modern navigators are equipped with such programs (although the name of pre-installed maps is not indicated for all models). Note that the functionality of complete programs in different models may vary. Most often, these are the simplest maps of the world or the region in which this device is sold. However, there are exceptions: there are models with detailed maps, programs with advanced functionality, etc. Such exceptions are especially common among high-end specialized devices, in particular marine and aviation (see "Scope"). And for some navigators, there may be several options for pre-installed programs and even the ability to select such programs at the request of the user. All these details should be specified in each case according to the manufacturer or seller.
It is also worth considering that the characteristics often indicate only the general name of the cards. At the same time, the same card can be available in several versions that differ in functionality and, sometimes, terms of use (paid / free). However, the main features are basic capabilities, interface device, etc. — usually, are common to all versions. Therefore, by the name of the complete programme, usually, one can quite accurately determine the general capabilities and features of the card's functionality.
Bands number
The number of communication channels supported by the navigator.
One communication channel allows the device to receive one operating frequency from one satellite. Without going into unnecessary details, we can say that the greater the number of channels, the more efficient the navigator works (including in dense urban areas and other adverse conditions) and the less time it takes for a “cold” start. On the other hand, numerous supported frequencies complicates the receiver and increases its cost.
As for the specific number, 12 channels are needed to work effectively with GPS, but today such receivers are considered obsolete and are almost never used. Most low-cost receivers support about 20 channels (there are also more modest solutions, at 16 or even 14 frequencies), mid-range solutions have about 30 – 40 channels, and in advanced models this number is most often 64 or 66 (although sometimes more) .
Battery life
The operating time of the navigator on one battery charge or a set of batteries depends on the power source (see above).
This parameter is more visual and closer to reality than technical information about the type of batteries, battery capacity, etc. However note that the operating time is usually indicated for a conditional perfect situation: a good signal level without the need to reconnect, low screen brightness ( or completely turned off the backlight), minimal use of wireless modules (Wi-Fi, Bluetooth), etc. Practical conditions inevitably differ from perfect — accordingly, the operating time may differ noticeably from the claimed one (usually in the direction of reduction, but sometimes vice versa) . Nevertheless, the operating time stated in the characteristics is quite reliable information, and it is quite possible to evaluate the capabilities of the selected device, as well as compare it with other models.
