In this article we will explain why it happens that often the connection to our WiFi network is of poor quality, breaks or cannot be established at all. Each of us, at home or in the office, has faced the so-called problem of weak connection to the wireless router. First of all, let's note that there are many factors that can affect signal quality and are probably unknown to most users.

Usually, the connection we make from our device, be it laptop, phone or other, to the WiFi network is determined by several basic parameters:

• Standard WiFi network
• Signal strength or power
• Number of connected devices
• Security protocols
• External influence from other devices
• Derivation of the parameters listed above

How to measure WiFi network signal strength?

For a good wireless connection, signal strength is a vital parameter, which we have to consider when planning the coverage area. Signal strength is expressed in decibel to milliwatt dBm and we should know that the smaller its value, the better the signal. In WiFi networks, it is represented as a decimal number with a negative value.

We must know that the strength of the signal also depends on the amplifying power of the antennas of the WiFi router and its quality can be affected by various factors, such as other wireless signals, distance between the devices and others.

A signal strength of -30dBm is better than a signal of -65dBm.

The video shows how when moving away from the WiFi access point, the signal strength changes from approx -20 dBm to about 55 dBm and vice versa. The test was done when moving away in a neighboring room about 6 meters away. Here, the main influence is the brick wall between the two rooms, and not so much the distance itself. At the end of the video, the device is in its initial position next to the access point (WiFi router).

What are the standards for WiFi networks?

Each protocol has a certain standard and for wireless WiFi networks it is IEEE 802.11x. The letter x at the end of 802.11 specifies the protocol version. Over time, these standards evolve and newer and newer versions are released that improve the performance of WiFi networks. We will not consider in detail all versions of the WiFi protocol, we will only list them and pay more attention to the most popular ones.

• 11a – 54 Mbps speed, 5 GHz frequency (ratified 1999)
• 11b – 11 Mbps speed, 2.4 GHz frequency (1999)
• 11g – 54 Mbps speed, 2.4 GHz frequency (2003)
• 11n – 450 Mbps speed, 2.4 GHz and 5 GHz frequency (2009)
• 11ac – 1.3 Gbps speed, 5 GHz frequency (2013)
• 11ac (wave 2) – 3.5 Gbps speed, 5 GHz frequency
• 11ax (WiFi-6) – 4 times faster than 11ac standard

Currently the most used protocols are 802.11n and 802.11ac.

See how the two protocols differ in the following table:

How do I choose which channel the WiFi network works on?

Bandwidth at 2.4GHz starts at 2.412GHz and ends at 2.472GHz. It is divided into 14 separate channels, with most of them overlapping except for the channel 1, 3 and channel 11. In each case, the frequencies that we can use are determined by a control body, in Bulgaria this is done by the KRS. The width of each channel can be 20MHz or 40MHz in the 802.11n standard and 20MHz, 40MHz, 60MHz and 160MHz for the standard 802.11ac.
The channel selection when setting to WiFi network is one of the main factors that can affect signal quality. It is good to scan the airwaves in advance to see if the networks around us are not using the same channel.

At the beginning of the video, you will see all possible channels - 14 in number, in the perfect case, when there are no other networks around you, the channels will be free.
Our network Geletron is located on 5th channel (in light blue), we gradually start to include the other networks and notice how many there are. The idea is to choose a channel where there are no competing WiFi networks or even if there are they have as weak a weak signal as possible.
This will reduce the risk of interference and improve signal strength between devices.

Some devices support operating frequencies of 5GHz, such as the 802.11n standard, as well as the standard 802.11ac, which however does not support 2.4 GHz. The good thing about it is that nowadays it is rare and the airwaves are almost always free.
WiFi networks that operate at 5GHz can reach much higher speeds when exchanging data because they use a wider channel bandwidth from 20MHz to 160 MHz. The bad thing about them is that the power of the signal drops dramatically when increasing the distance or the presence of physical obstacles, such as walls, doors and more. In the video above, you saw how many networks use 2.4GHz frequencies, which often cause problems.

Here is an example with 5GHz frequencies:

As you can see, there is only one network in this bandwidth and that is ours. The use of these frequencies is recommended for places with a concentration of many networks, but is it about longer distances or other circumstances, it is better to use the 2.4GHz frequencies.

Keep in mind that the speeds specified by network device manufacturers are rarely exceeded 50% in real life conditions, especially when transferring data, and when there are other factors, these speeds can also degrade to 10%.

Here are some links to an app that can scan WiFi networks, you can use any other you find on the Internet.

Android: https://play.google.com/store/apps/details?id=com.metageek.inSSIDer&hl=en
iPhone: https://itunes.apple.com/us/app/wifi-scanner/id411680127?mt=12
Windows: http://www.techspot.com/downloads/5936-inssider.html
MAC: https://www.macupdate.com/app/mac/48147/inssider

Let's summarize - what could be the reasons for a bad wireless connection:

– our WiFi router / wireless access point has weak technical parameters

– our end device (laptop / phone) has weak technical parameters

– other wireless networks broadcast on the same frequencies / channels

– there are obstructions or a long distance, resulting in weak signal strength

If you manage to remove these obstacles, you will undoubtedly enjoy a stable and fast connection to the wireless network.

So far we have understood some basic things to measure signal strength, the choice of WiFi standard and frequency channels.

What device is best to choose and why, we will show you in the following article.

Consult us if you need professional help for network building, which is safe, reliable and according to established standards.