LAN
In this case, LAN means standard network connectors (known as RJ-45) designed for wired connection of LAN devices — PCs, servers, additional access points, etc. The number of ports corresponds to the number of devices that can be directly connected to wired equipment. way.
In terms of speed,
100 Mbps (Fast Ethernet) and
1 Gbps (Gigabit Ethernet) are the most popular options today. At the same time, thanks to the development of technology, more and more gigabit devices are being produced, although in fact this speed is critical only when transferring large amounts of information. At the same time, some models, in addition to the standard speed of the main LAN ports, may have
a 2.5 Gbps, 5 Gbps and even 10 Gbps LAN port with increased bandwidth.
MU-MIMO
Device support for
MU-MIMO technology - multi-user multi-threaded I / O.
Communication in multiple streams is implemented through the use of multiple antennas on both the transmitting and receiving device. This allows you to increase the bandwidth of the channel, as well as improve the overall quality and stability of the connection. And the term "multi-user" usually means that Wi-Fi equipment is able to simultaneously work with several external devices that support multi-streaming (MIMO). The only exceptions are Wi-Fi adapters (see "Device type") - they are more about the ability to interact with the router / access point as efficiently as possible, which also uses MU-MIMO.
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".
Transmitter power
Rated power of the Wi-Fi transmitter used in the device. If multiple bands are supported (see “Ranges of operation”) the power for different frequencies may be different, for such cases the maximum value is indicated here.
The total transmitting power provided by the device directly depends on this parameter. This power can be calculated by adding the transmitter power and the antenna gain (see above): for example, a 20 dBm transmitter coupled with a 5 dBi antenna results in a total power of 25 dBm (in the main antenna coverage area). For simple domestic use (for example, buying a router in a small apartment), such details are not required, but in the professional field it often becomes necessary to use wireless devices of a strictly defined power. Detailed recommendations on this matter for different situations can be found in special sources, but here we note that the total value of 26 dBm or more allows the device to be classified as equipment
with a powerful transmitter. At the same time, such capabilities are not always required in fact: excessive power can create a lot of interference both for surrounding devices and for the transmitter itself (especially in urban and other similar conditions), as well as degrade the quality of the connection with low-power electronics. And for effective communication over a long distance, both the equipment itself and external devices must have the appropriate power (which is far from alway
...s achievable). So, when choosing, you should not chase the maximum number of decibels, but take into account the recommendations for a particular case; in addition, a Wi-Fi amplifier or MESH system often turns out to be a good alternative to a powerful transmitter.
