Research on the process of WiFi communication--(2) WiFi Transmission authentication process

Second, the WiFi transmission authentication process

(i), terminal and router authentication process

1. Wireless Scanning

The user access process first requires an active/passive scan, then the authentication and association of two processes before connecting with the AP.

2. Certification process

In order to prevent illegal user access, the first need to establish authentication between the user and Ac/fatap/gateway, the authentication mechanism includes two kinds. Only through certification can we enter the association phase.

– No Encryption authentication

Use the SSID (Service Set ID) as the most basic authentication method.

Open System Certification

Closed-Systems Certification

– Shared Key authentication

Use the shared secret to authenticate and use the WEP (Wired equivalent Privacy) key as the shared key.

Figure 6 Certification process

3. Correlation process

If the user wants to access the wireless network via an AP, the user must be associated with a specific AP. When a user selects a wireless network by specifying the SSID and passes the AP authentication, the associated request frame can be sent to the AP. The AP adds user information to the database and responds to the user with the associated response. The user can only associate to one AP at a time, and the association is always initiated by the user.

Figure 7 Association Process

Figure 8 Transfer process

Figure 9 WiFi connection

Figure 10 Information Transfer process

The AP ends with the 802.11b/G protocol between the terminals and translates into a 802.3 protocol to access the traditional LAN network, as shown in 11.

Figure 11 Protocol conversions

Research on the process of WiFi communication--(2) WiFi Transmission authentication process