Our demand for WIFI is just like we need air. We hope that there will be smooth WiFi available anytime and anywhere. In low-density places, it is better to say that you can use wireless routers or a small number of wireless APs to complete this effect. But what about high-density places, such as venues, conferences, classrooms, etc?
For larger venues, our first choice is undoubtedly the wireless AP+AC networking architecture. So how do you apply wireless APs to build, what should you pay attention to during the process? Let's take a look today!
The deployment of WIFI networks is far more complicated than most people think. It is not to say that dozens of APs are put on, and the bandwidth is automatically increased by several times. On the contrary, if you put dozens of APs casually, the bandwidth will quickly drop the bandwidth to be almost unusable due to the competition between APs. That is to say, the rate of bandwidth does not rise but decreases.
Generally for high-density WiFi coverage planning, the following steps should be known:
1, the situation investigation. For example, the size of the site in the field environment, the number of people, the number of WiFi users, the distribution of the layout, etc., it is best to look at the map of the site to have a rough estimate of the size and deployment of the network.
Generally speaking, it is necessary to plan at least one client device for each person. The past experience can be planned according to 0.5 clients. Due to the popularity of smartphones and tablets, it is estimated that 1.5 to 2 clients will be close in the future. It is possible for mobile phones and laptops or tablets to be online at the same time.
2, bandwidth estimation. Generally, to ensure the normal use of relatively lightweight Internet applications, the most basic device should allocate 500kbps of available bandwidth. If you upload a video, the bandwidth is higher.
3, AP planning. After calculating the bandwidth requirements of each area through the above two points, the next step is AP planning.
In a case where the rate requirement is not high, generally only 35 Mbps is guaranteed for most mobile phones, and 70 Mbps or higher can be guaranteed for MIMO supported by notebook computers and the like. For the speed requirement, you can increase the transmission rate by 2~3 times. In order to ensure the communication quality, in order to ensure a better experience, in fact, it should be controlled that each AP accesses the device no more than half of the number just calculated.
4, channel allocation. The wireless AP has 2.4G and 5.8G points. Among the 11 channels of 2.4G, only 1, 6, and 11 channels that do not overlap each other can be used. The 5.8G available non-interfering channels have 5 channels with a width of 20MHz. They are 149, 153, 157, 161, and 165, respectively. Sometimes if it is not possible to cover without overlapping, then consider using a sector antenna to subdivide the coverage area into several sectors.
5. Field deployment. High-gain antennas should be considered for deployment, but reduce the transmit power of each AP so that its coverage area is basically consistent with the planned area. Note that the higher the power, the better. You should let each AP cover only the planned area. Deployment may require some on-site measurement tools to evaluate the effectiveness of the deployment to prevent dead spots due to multipath interference.
6, SSID allocation. Wifi users are usually mobile and may need to go around, possibly from an AP's network to another AP's network. At this point, seamless roaming is required, and the premise is the SSID setting and allocation. The specific approach is to set all wireless APs to the same SSID.
7, user authentication and bandwidth control. In order to prevent malicious network, it is best to do basic authentication for users, be sure to set a password. At the same time, limit the bandwidth usage for each account, which also involves user authentication and bandwidth management, usually requiring additional servers to process.
8, load balancing. In practical applications, there is often a strong signal of the AP and a weak signal of the AP. If an AP can receive the client signal but the strength is too weak to support a certain threshold rate, the client is rejected from this. AP access, which requires the AP to support automatic load balancing.
Finally, if the WiFi network is faulty or cannot be used normally after deployment, you can check and redeploy from the following aspects: insufficient number of APs, unreasonable AP planning, insufficient AP capacity, AC controller crash, The authentication service crashed, the export bandwidth was too narrow, and management was chaotic.
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