Gain
Gain provided by each device antenna; if the design provides for antennas with different characteristics (a typical example is both external and internal antennas), then the information, usually, is indicated by the highest value.
Amplification of the signal in this case is provided by narrowing the radiation pattern — just as in flashlights with adjustable beam width, reducing this width increases the illumination range. The simplest omnidirectional antennas narrow the signal mainly in the vertical plane, "flattening" the coverage area so that it looks like a horizontal disk. In turn, directional antennas (mainly in specialized access points, see "Device type") create a narrow beam that covers a very small area, but provides a very solid gain.
Specifically, the gain describes how powerful the signal is in the main direction of the antenna compared to an perfect antenna that spreads the signal evenly in all directions. Together with the power of the transmitter (see below), this determines the total power of the equipment and, accordingly, the efficiency and range of communication. Actually, to determine the total power, it is enough to add the gain in dBi to the transmitter power in dBm; dBi and dBm in this case can be considered as the same units (decibels).
In general, such data is rarely required by the average user, but it can be useful in some specific situations that specialists have to deal with. Detailed calculation methods for suc...h situations can be found in special sources; here we emphasize that it does not always make sense to pursue a high antenna gain. First, as discussed above, this comes at the cost of narrowing the scope, which can be inconvenient; secondly, too strong a signal is also often undesirable, for more details see "Transmitter power".
Operating temperature
Ambient air temperature at which the device is guaranteed to remain operational.
All modern Wi-Fi equipment can easily endure the conditions typical for use in apartments, offices, etc. So it makes sense to pay attention to this parameter mainly when choosing a model for outdoor installation (see above) or indoors , where the conditions are not very different from those outside. At the same time, the upper temperature limit is usually quite high, and even in the heat there are usually no problems with operation (of course, if the device is not installed in direct sunlight — which is not recommended anyway). But the lower temperature threshold can be different, not all "street" equipment is designed for frost. However, among frost-resistant models there are solutions where the minimum operating temperature is
-10 °C and below, and sometimes even
-40 °C and below.
