Content
In this article I want to talk about the fundamental factors of building a quality wireless bridge, since many "network builders" believe that it will be enough to buy quality network equipment, install and get 100% return on them - which in the end not everyone succeeds.
CCQ - what is it?
CCQ (Client Connection Quality) is translated from English as βclient connection qualityβ - which basically shows the percentage ratio of the theoretically possible to the actual current channel bandwidth, in other words, the percentage of bandwidth achieved with the maximum possible on specific equipment.
For example, you use equipment with the maximum possible throughput of 200 Mbps, and in fact on the current channel 100 Mbps - in this case, CCQ is 50%
in network equipment ΠΈ there are two separate indicators
Tx. CCQ (Transmit CCQ) - data transfer rate.
Rx. CCQ (Receive CCQ) - data reception rate.
Three main factors affecting the quality of CCQ
1. Alignment of two antennas. If we talk about a point-to-point wireless bridge, then it is clear that the antennas should look at each other as accurately as possible, βeye to eyeβ.
If you need a point-to-multipoint wi-fi bridge, then initially you need to think through the entire architecture from the provider's sector antenna to the client ones, so that they intersect as accurately as possible.
2. The presence of noise in the channel. Before deciding on the frequency of the wi-fi bridge, be sure to check each frequency for noise, based on this check, stop at a less loaded frequency.
3. Fresnel zone.
Fresnel zone - what is it?
The Fresnel zone is the volume of the radio wave channel between two antennas.
The maximum channel volume is at the center point between the two antennas.
For the highest quality signal, you need to select the cleanest zone, both from physical obstacles and from radio waves (as discussed in the second paragraph).
How to calculate Fresnel zone?
The formula for calculating the Fresnel zone at its central point:
D - distance (km)
f - frequency (GHz)
The formula for calculating the Fresnel zone at any of its points, for example, at the place of an obstacle:
f - frequency (GHz)
D1 - distance to the calculation point you need, from the first antenna (km)
D2 - distance to the calculation point you need, from the second antenna (km)
By carefully working through these three factors, you will end up with a stable wireless bridge, with the highest possible data transfer rate.
Source: habr.com