There are more and more wireless WiFi coverage projects. In the weak current VIP technical team, friends often encounter some problems when doing WiFi coverage projects, especially large and medium-sized wireless coverage, involving practical problems such as channel planning, common frequency interference, network delay and so on. The following are some basic knowledge and common questions about wireless WiFi coverage of weak current engineering construction company.

1. What is common frequency interference

Co frequency interference is an inevitable problem in wireless WiFi Coverage Engineering. Co channel interference refers to the interference and delay when two APS work at the same frequency.

2. Historical origin of co channel interference in wireless WiFi

WiFi design didn't expect it to be so popular. 11 channels are planned, and 11 wireless devices in one area are enough. But later, WiFi was upgraded twice, and a device used two or four channels for transmission at the same time, which led to today's situation. One device uses four channels. In order to avoid mutual interference, the two devices need to be separated by five channels, that is, 1, 6 and 11 are separated from each other, resulting in only three wireless devices in an area, which is obviously less, and is prone to common frequency interference.

3. How to plan the wireless WiFi channel

In the wireless WiFi coverage project, in order to reduce the signal blind area, multiple APS need to be deployed to complete the overlapping area of wireless coverage. Pay attention to the reasonable planning and use of wireless channels. Adjacent APS are separated from each other by 1, 6 and 11.

4. How to deploy wireless AP and channel optimization to avoid co channel interference

The effective way to avoid the same frequency interference is to set the adjacent AP interval as 1, 6 and 11, and the distance between the same channel as far as possible. Professional antenna feeder coverage is adopted for mobile and Telecom. Industrial Wireless APS are connected with 4-8 antennas through feeders. One AP occupies one channel and covers one floor or the whole building, effectively avoiding common frequency interference.

5. What is the impact of WiFi co channel interference

Co channel interference in wireless networks will lead to network packet loss and delay, poor wireless network quality and slow network speed. Since the working frequencies of the two APS are the same, mutual interference leads to frequent repeated data transmission. The higher the network frequency, the more serious the co channel interference.

6. Install antenna fed wireless WiFi coverage walkway

For large and medium-sized wireless WiFi coverage projects, antenna feed coverage mode is recommended. The industrial wireless AP is connected with 4-8 antennas through the feeder, installed in the corridor and penetrating the rooms on both sides. Antenna fed WiFi is a professional coverage mode, which is usually used for mobile and telecom coverage of railway stations, hotels and office buildings. Antenna feed coverage can use one AP for one floor or the whole building to optimize the wireless channel. Layer 1 uses one channel, layer 2 uses six channels, and layer 3 uses 11 channels, avoiding the same frequency interference. Users enter and leave under the same AP to reduce cross AP switching and realize seamless roaming.

7. Install antenna feed wireless WiFi coverage
Where the environment is relatively closed and there are many walls, the corridor device has great attenuation to the wireless signal and can be installed at home. The industrial wireless AP adopts 16-32 antennas, adopts super flexible feeders to enter the room, and indoor beautification antennas are installed. In this way, the coverage signal is uniform and there is no dead corner.