Coverage of Wireless LAN

The development of wireless LAN has become increasingly mature. However, in this development, extensive coverage connections are not common. How can this problem be solved? Multi-AP wireless coverage will be a good solution.

Wireless LAN makes people feel relaxed and free. However, at present, this "freedom" is very limited. Most wireless LAN is confined to a small indoor space, and extensive coverage and connection are not universal.

At present, most wireless LAN is using a GHz frequency band, with poor penetration and diffraction capabilities. In addition, the quality of modern buildings is getting higher and higher, which forms a strong shielding effect on the room, as a result, the area covered by the wireless LAN is very limited, and the AP communication range is limited to a certain extent. Wi-Fi technology is used to establish a "Hotspot" with no barrier transmission distance of only 30 ~ The area is about 50 meters. If the user moves too fast or exceeds this range, the connection to the network will be lost. Wireless LAN users are often bound to a local space. Once they exceed the subnet coverage, they will not be able to continue communication and enjoy the flexibility of the mobile process.

To address this problem, the multi-AP micro-cellular wireless coverage solution is a good solution. It can expand the overall wireless coverage area and achieve roaming at any location. Through the collaboration of multiple APs, this scheme can effectively expand the coverage area of the wireless network and achieve the goal of wireless roaming in large active spaces. In this way, the wireless LAN is not limited to data transmission within a small range, as the name suggests. For example, AboveCable uses the wireless network micro-cell coverage roaming technology. In principle, it is very similar to mobile phone's cellular system. It allows a user to roam freely in different AP coverage areas. As the location changes, the signal is automatically switched from one AP to another. The entire roaming process is completely transparent to users. Although the AP providing the Connection Service is switched, the service will not be interrupted, this allows you to "carry" your own internal network anytime and anywhere. In addition to the bridge function, the AboveCable AP also provides the transfer function. It can transfer a mobile workstation from an AP to the next AP, to ensure a stable connection between the mobile workstation and the wired trunk, and achieve continuous network coverage within a certain range. In addition, AP uses nP & P (network Plug & Play) technology to solve the problem of IP address transformation. This zero-configuration network function makes it possible to access wireless networks conveniently.

To implement micro-cellular coverage, we must first establish a wireless network containing multiple APs, and then form a complete micro-cellular system. The scope of services to be provided is divided into several basic service areas. Each region consists of an AP and its associated wireless workstation, the wireless workstation is associated with the wireless access point using the basic service area identifier BSSID of the AP), covering a region similar to a honeycomb. Each micro-cell has a coverage radius of dozens of meters. Internal devices use the same channel to communicate with each other. Channels of adjacent cells are different, and links between cells use wireless devices. In a wireless micro-cellular system, each AP becomes the first device to provide services. It controls user authentication, access policy execution, authorized network services, and resource usage review and tracking.

Then, multiple APs are connected to the wired network respectively to form a multi-AP wireless network based on the wired network. all APs share the essid of the same extended service area ). When a customer enters one or more aps in the nearest region, it automatically selects an AP for connection based on the signal strength and packet error rate. Once accepted by an AP, the client converts the frequency band that sends and receives signals to the AP frequency band to access the resources of the entire network.