1. What is a channel?
Channel, also known as Channel or frequency band, is a data signal transmission channel that uses wireless signals as the transmission carrier.
The operating frequency of the 2.4G band is 2.4-2.4835 GHz. The 83.5MHz band is divided into 13 channels. The center frequency of each channel is 5 MHz, and 11 MHz is extended up and down respectively, and the channel bandwidth is 22 MHz. China adopts the European/ETSI standard and uses 1-13 channels. As shown in the following figure:
Similar wireless routers use the same or overlapping channels to form a channel competition relationship, which affects the quality of wireless links. To effectively avoid mutual interference caused by overlapping channels, similar wireless routers should work on non-overlapping channels, such as (1, 6, 11) and (1, 7, and 13). However, wireless routers do not have to work on these channels.
II. Automatic channel selection
Early wireless routers preset the same channel (mostly 6) when leaving the factory, because users rarely modify the channel, resulting in mutual influence. With the rapid popularization of wireless applications, wireless routers have added the channel auto-selection function. When the device starts, it detects the distribution of the surrounding wireless channels and selects the optimal channel.
The auto-selection function of wireless channels is as follows: Overlapping channels can cause mutual interference between wireless routes, thus affecting the quality of wireless transmission. The automatic channel selection function enables the router to automatically set the optimal working channel according to the surrounding wireless environment, effectively avoid interference or competition with the same frequency.
3. When do I need to manually select a channel?
In the following applications, we recommend that you manually select the channel of the router:
1. The traditional interface router is recommended to set a fixed channel when WDS wireless bridging or multiple wireless routers are set to roaming network through LAN-LAN cascade;
2. Some wireless terminals may not be able to identify channels 12 or 13. When the router automatically selects the two channels, the wireless terminal cannot find the signal. In this case, the channel of the router must be fixed between 1 and 11.
3. Serious wireless interference. The auto-selection function of wireless channels is automatically set to the optimal working channel according to the current environment after the vro is started. The channel will not change until the vro restarts, but in the actual environment, the wireless environment around the vro may change during operation, causing strong wireless interference. In this case, you need to manually set the channel.
4. How to manually select the optimal Channel
When you manually set the channel of the router, you must avoid using the same channel as other wireless signals to avoid interference with the same frequency. So how can we know the channels used by other wireless signals? There are two methods:
Method 1: Use the WDS scanning function of the router
Some wireless routers support the WDS function on the router interface.
Enable
WDSFunction,
Scan
Wireless signals.
You can view the channels and signal strength of other wireless signals in the surrounding environment from the scan results, as shown in the figure below:
Note:: The new interface and the cloud router set WDS wireless bridging without a fixed channel. When scanning the surrounding wireless signal, the surrounding wireless signal channel is not displayed.
Method 2: use third-party software
The WDS function of some wireless routers does not display the channels with other wireless signals. Third-party software such as inssider can be used. To download and install the inssider software on your computer, you must install a wireless network card. In the software, you can scan the channels and signal strength of wireless signals in the surrounding environment, as shown in the figure below:
Note:: The signal strength is expressed as a negative number. The smaller the absolute value, the stronger the signal. For example, if the intensity of A signal is-45 and that of B is-70, the signal A is stronger than that of B.
Select an unused channel or a weak signal from your wireless router based on the channel and strength used by other signals in the surrounding environment.
