How to choose an access point?
An access point is a device designed to transmit an Internet signal from a distribution device, router. Unlike these devices, the access point does not distribute traffic – it is distributed evenly to all devices connected to it. In other words, the function of the access point is to extend the range of routers.
As a rule, they are connected using a twisted pair cable (LAN), and the signal is transmitted over a wireless VLAN channel using Wi-Fi protocols. When selecting the type of wired connection, consider the data transfer rate of the signal source. Depending on this, select a device with a Fast Ethernet, Gigabit Ethernet, or another connection interface, taking into account that the access point’s data transfer speed can not exceed the speed of the distributing device.
As a gateway to the Internet, each access point has an IP address in the global network, static or dynamic. Accordingly, it is assigned a name and other identifiers.
Access points are widely used for network coverage of buildings and premises, organizing access in public places, and serving as repeaters of routers.
Wi-Fi is a wireless data transfer Protocol that is currently widely used for applications in domestic settings, public places, and commercial organizations. Several parameters determine the operation of the channel. These include:
- operating frequency;
- data transfer rate
- network standard.
The operating frequency of Wi-Fi is the clock frequency of the wireless channel. The most commonly used rates are 2.4 GHz and 5 GHz, each of which has its advantages. At 2.4 GHz, the signal is most effectively propagated through mechanical obstacles, but it is the most saturated with interference. Simultaneously, despite the lower penetration capacity, the signal transmitted at a frequency of 5 GHz is affected by interference to a much lesser extent.
There are access points on the market that operate at these and other frequencies, and the existing installation conditions determine their choice. Devices that support both 2.4 / 5 GHz frequencies are very convenient to use – you can evaluate the use of a particular rate in them in manual mode, and switching between frequencies can occur automatically.
It depends on the technical capabilities of the device and the speed of the incoming flow. It can range from 54 Mbit/s to several thousand. It should be noted that the characteristics indicate the nominal speed, the real one, as a rule, differs from the nominal one in a smaller direction.
Devices that work with a Wi-Fi data link use the IEEE 802.11 family of network standards. Different standards differ in bandwidth and frequency, and these differences are displayed in letter indexing. Each standard has specific characteristics.
Note that the value of the specified speed is the connection speed. The standards are not compatible, so access points that support multiple channels at once are common.
Antenna gain and MIMO
The gain factor (CU) of an antenna is its ability to concentrate the transmitted signal in a certain direction. In this case, due to the higher” density ” of the signal compared to evenly radiating antennas, its amplification is created, although physically, the antenna itself cannot amplify the signal power. CU is calculated in decibels (dBi).
From the above, it is evident that the antenna’s gain is related to its directional coefficient and efficiency (taking into account the signal loss in the transmitter structure itself), but this relationship is not linear. Access points have a CU from 2 dBi to 20 dBi and higher.
We should also mention the MIMO data transfer technology. Its essence is that the data stream is transmitted and received not by one but by several antennas simultaneously. This is why the MIMO designation indicates the number of receivers and transmitters, such as MIMO 2×2 or MIMO 4×4. Also, the technology uses simultaneous transmission of multiple data packets over a single channel. Together, this allows you to increase the speed of information transfer significantly – without the use of MIMO, it is difficult to imagine wireless transmission at speed higher than 300 Mbit/s.
The described characteristics are closely related to the coverage range of the access point, ranging from several tens of meters to hundreds of kilometers.
When choosing an access point, pay attention to additional features:
A version of the device. Access points designed for outdoor installation are additionally protected from moisture and dust.
Availability of USB ports.
The possibility of power supply via a “twisted pair” is Swarm, which eliminates the need to install power outlets.
Availability of power supply.
Completeness (protective cover, installation kit, etc.).
What you should pay attention to when purchasing APN
If you still decide to purchase an APN, please note the following characteristics:
- maximum number of connected devices-shows how many devices APN can serve at the same time. Of course, if the APN is installed at home, where 2-4 devices will connect to it, this parameter is not essential, but for organizations where the number of devices exceeds one hundred, this is important;
- how to manage it, whether there is special software from the manufacturer;
- maximum and minimum data transfer speeds;
- the encryption method, WPA or WPA2 is recommended, and the more outdated way is WEP;
- frequency range-also affects the connection speed, compatibility, range, and ability of the signal to bypass physical barriers.
- Select a device based on the price/quality ratio. Ask the seller to tell you which APN is best for your needs.