WLAN/directional radio technology

Reading time 4 minutes

Updated – December 30, 2022

Basics

WLAN serves as local access to a network infrastructure, while the distance between two stations is increased using directional radio antennas.

WiFi everywhere – that’s how you want it to be. But the manufacturers' full-bodied promises often don't keep what they seem to promise.

To be honest, it is not due to their supposedly excessive range promises, but rather due to the local conditions, which do not correspond to the ideal standard: reinforced concrete, walls, ceilings, trees, etc. all represent obstacles to radio waves. The shorter the wavelength, the higher the damping caused by obstacles.

WiFi is covered by two band ranges: 2.4 GHz and 5 GHz.

There are different IEEE standards within these bands, currently represented in the 2.4 GHz band are 802.11b with up to 11 MBit/s at a 20m range, 802.11g with up to 54 MBit/s at 25...50m range, in the 5th GHz band 802.11n with up to 600 MBit/s with a range of 70m, 802.11ac with up to 1,300 MBit/s, as well as in the 60 GHz band 802.11ad with up to 7 GBit/s with a range of 50m and 802.11ay with up to 175 GBit/s with a range of just 10m.

As is usual with DSL data throughput information, the range here also says “up to” x meters. This generally assumes a clear line of sight.

WiFi coverage

Daring fellows recommend using so-called repeaters to increase the range. This ignores the fact that the repeater would have to send and receive at the same time in order to be able to deliver the same data transfer rate. But that's exactly what he can't do. While he is listening, he cannot speak and vice versa. Therefore, the throughput that can be achieved with a repeater is reduced by 50%.

If you want homogeneous Wi-Fi coverage, then you can't avoid having a corresponding number of Wi-Fi access points, if in doubt even one per room if you want almost maximum performance to be available everywhere.

The radiation diagrams, which show the radiation characteristics of the AccessPoint, are often ignored because they are rarely shown in the technical data sheets of the AccessPoints. Depending on the arrangement of the antennas, this can be circular, conical, or similar to an ellipse, or a combination of all. Knowing these characteristics, the illumination of corners can be increased if necessary, provided that these measurement data are taken into account when installing the AccessPoint. For special applications, there are also sector antennas that specifically illuminate a narrow, conical corridor.

Selection of components

Products from well-known manufacturers, including routers, are often found and perform their job safely for household use. If you want an environment that can be administered remotely, if necessary, but primarily consistently and cleanly, you should use an enterprise provider (e.g Ubiquity) evade. Ubiquity poses with his Unifi-Products Enterprise technology available inexpensively for the consumer sector.
All rack-mountable components have a relatively high operating temperature, but are also certified for this.
When installed in a network cabinet, in my opinion automatic ventilation using efficient fans makes sense, although not required by the manufacturer's specifications.

It must be taken into account that quality cannot be offered at a discount price. If you buy cheap, you buy twice. Although one often tends to ignore this truism, it catches up with us again and again with absolute reliability - sometimes sooner, sometimes later...

Case study

Below I present an extensive installation of 1x router (AVM 9590 Cable), 1x Security Gateway Pro 4, 12x switches, 9x access points (everything Ubiquity) and 1x 1 Gbit/s radio link (MicroTik), which covers a bungalow with three residential units with 360 sqm of living space and 2,000 sqm of outdoor area for around 90 clients.

Security Gateway Pro 4 / Unifi Cloud Key

The Unifi Security Gateway Pro 4 acts as a router and firewall in the enterprise segment, has two WAN and two LAN ports, each 1 Gbit/s, so that a redundant DSL connection can be implemented if necessary, e.g. WAN 1 -> cable DSL, WAN 2 -> LTE and, like all Unifi components, is administered via a controller that can be accessed via a browser.

The so-called Unifi Cloud Key enables (also remote) administration via mobile phone app or browser and eliminates the need to install the Unifi controller software on a computer. It is connected to any switch.
There is also one for this Rack mount accessory.

WAN 1 is connected to port 1 AVM 6950 Cable connected. Please note that the AVM router uses a different subnet than the Unifi infrastructure (e.g. AVM 192.168.0.x and WAN 1 192.168.1.x). LAN 1 leads directly to the switch (here 48-port).

Using the Unifi Security Gateway and the controller, any number of LAN and WLAN networks can be configured within a few minutes, including guest networks with a guest login portal or without a separate login, all with VLAN support, of course.

Three LAN networks, each with their own subnet, and four WLAN networks were set up here.

Unifi switch

All Unifi switches can be administered via the controller and some have POE according to 802.3at/af and SFP ports. The switching capacity is 16 / 20 (8-port / POE).. 104 (24-port) GBit/s.

Switches used here are:

• Unifi Switch 8-port (4-port POE)
• Unifi Switch 8-port POE 2 SFP
• Unifi Switch 48 port 2 SFPs
  

Unifi AccessPoint

Ubiquiti offers different variants, including: Unifi AP AC LR (long range, indoor), and PRO (outdoor).

Long range sounds tempting at first, finally more range, up to 183m. Yes on the receiving side, BUT: which of the local devices, such as cell phones, tablets etc. support a long range mode on the sending side?!
So please forget about LR straight away, it's better to go for PRO with a range of up to 122 m, even for indoor use.
Well, 122m, one access point should be enough for the whole apartment! Incorrect: “122m”, firstly “up to” and secondly “open field visibility condition”.
Even a single exterior wall reduces the 600 Mbit/s available outside to approx. 140 Mbit/s, both times based on a distance of 2m at an angle of 45° to the access point! Each additional wall reduces the data throughput again.

The Unifi AP AC PRO-Version offers 3 x 3 TX/RX MIMO antennas at 2.4 GHz and 5 GHz with a maximum throughput of 450 MBit/s or 1.3 GBit/s, has 2 x 1 GBit/s LAN ports (e.g. for a LAN-connected POE video camera).

Radiation diagrams are below https://help.ui.com/hc/en-us/articles/115005212927-UniFi-UAP-Antenna-Radiation-Patterns available.

MikroTik radio link

Ubiquiti currently offers a new directional radio antenna Ubiquiti PowerBeam 5AC ISO Gen2 with 450 MBit/s over a distance of up to 25km (!) (may be of interest to farmers) at an acceptable price. However, Otto-Normal has to bridge distances of less than 100m (house – garden). This realizes that MikroTik 1Gbps Wireless Wire Kit with a stable 800 MBit/s over a distance of 60m. For example, parallel video streams from 5 high-resolution Hikvision cameras, Netflix TV, games console, games PC, two cell phones and tablets, as well as two Raspberry Pi computers are processed here.

The only downside: the antennas have to be administered via their own IPs via the web GUI. With the Unifi radio link, this would work via the Unifi controller.
If you can live with this limitation, this MikroTik solution is recommended.