Configure Wi-Fi Network to Support EAP-SIM:
- The Wi-Fi network, specifically the RADIUS server (Authentication server), must be configured to support EAP-SIM for authentication.
- The network provider’s infrastructure should support 3GPP AAA servers or similar infrastructure that allows the Wi-Fi network to communicate with the Home Location Register (HLR) or Home Subscriber Server (HSS) to authenticate the SIM credentials.
Steps:
- The Wi-Fi access point (AP) is configured to use WPA2-Enterprise (or WPA3-Enterprise for enhanced security).
- In the AP's configuration, select EAP-SIM as one of the supported authentication methods.
- The AP communicates with a RADIUS server, which verifies the subscriber's identity through the Mobile Core Network using the SIM card information.
Wi-Fi Passpoint Network Configuration:
- Passpoint profiles are used to configure client devices to automatically connect to Passpoint-enabled networks.
- The Passpoint profile for a network that supports SIM-based authentication will specify EAP-SIM as the authentication method.
- The network's Online Sign-Up (OSU) Server can also deliver the profile to compatible devices, so they can connect automatically.
Steps:
- In the Access Network Query Protocol (ANQP) settings, configure EAP-SIM as a supported authentication method.
- The ANQP responses from the AP will indicate to the device that the network supports EAP-SIM, allowing devices with SIM cards to select this network for automatic connection.
Device-Side Configuration:
- On the client side (e.g., smartphones or tablets), Passpoint profiles are created by the mobile operator or network provider.
- Devices with Passpoint support will automatically select networks that match their Passpoint profile and initiate EAP-SIM authentication.
Steps:
- The device detects the Passpoint-enabled network and checks the profile for available authentication methods (such as EAP-SIM).
- The device automatically chooses EAP-SIM and sends the SIM card information (IMSI) to the network.
- The RADIUS server communicates with the mobile operator’s backend to verify the SIM card’s information.
Authentication Process (EAP-SIM):
- When a device with a SIM card attempts to connect to a Passpoint-enabled network that supports EAP-SIM, the following occurs:
Steps:
- The device sends a request to authenticate using EAP-SIM.
- The access point forwards this request to the RADIUS server.
- The RADIUS server then communicates with the Mobile Core Network, querying the HLR or HSS to authenticate the device using the IMSI and other SIM data.
- The mobile network sends a challenge-response mechanism back to the device, which uses the SIM card to respond and complete authentication.
- Once authentication is successful, the device is granted access to the network.
SIM-Based Roaming:
- When the network is set up for roaming, SIM-based authentication works across different networks with roaming agreements.
- A device using SIM-based authentication can automatically connect to Wi-Fi networks provided by a partner operator in a different country or region.
Advantages of SIM-Based Authentication in Passpoint:
- Seamless Authentication: Users do not need to manually select a Wi-Fi network or enter credentials. The SIM card handles all authentication automatically.
- Roaming Support: EAP-SIM enables users to roam between Wi-Fi networks that have roaming agreements with the user’s mobile operator, providing a seamless transition between Wi-Fi and cellular networks.
- Security: The authentication process is secure, leveraging SIM credentials that are difficult to compromise. EAP-SIM operates over WPA2/WPA3-Enterprise networks, ensuring encryption during data transmission.