Security and Roaming
Supported Wi-Fi Security Modes
ESP32 supports the following Wi-Fi security modes. For detailed configuration and usage, refer to Wi-Fi Security.
Open
WEP
WPA-Personal
WPA2-Personal
WPA3-Personal
Wi-Fi Enterprise
Wi-Fi Easy Connect™ (DPP)
Wi-Fi Easy ConnectTM (or Device Provisioning Protocol) is a secure and standardized provisioning protocol for configuring Wi-Fi devices. More information can be found in esp_dpp.
WPS Enrollee
ESP32 supports WPS enrollee feature in Wi-Fi mode WIFI_MODE_STA or WIFI_MODE_APSTA. Currently, ESP32 supports WPS enrollee type PBC and PIN.
Wireless Network Management
Wireless Network Management allows client devices to exchange information about the network topology, including information related to RF environment. This makes each client network-aware, facilitating overall improvement in the performance of the wireless network. It is part of 802.11v specification. It also enables the client to support Network assisted Roaming. - Network assisted Roaming: Enables WLAN to send messages to associated clients, resulting clients to associate with APs with better link metrics. This is useful for both load balancing and in directing poorly connected clients.
Current implementation of 802.11v includes support for BSS transition management frames.
Radio Resource Measurement
Radio Resource Measurement (802.11k) is intended to improve the way traffic is distributed within a network. In a WLAN, each device normally connects to the access point (AP) that provides the strongest signal. Depending on the number and geographic locations of the subscribers, this arrangement can sometimes lead to excessive demand on one AP and underutilization of others, resulting in degradation of overall network performance. In a network conforming to 802.11k, if the AP having the strongest signal is loaded to its full capacity, a wireless device can be moved to one of the underutilized APs. Even though the signal may be weaker, the overall throughput is greater because more efficient use is made of the network resources.
Current implementation of 802.11k includes support for beacon measurement report, link measurement report, and neighbor request.
Refer ESP-IDF example examples/wifi/roaming/README.md to set up and use these APIs. Example code only demonstrates how these APIs can be used, and the application should define its own algorithm and cases as required.
Fast BSS Transition
Fast BSS transition (802.11r FT), is a standard to permit continuous connectivity aboard wireless devices in motion, with fast and secure client transitions from one Basic Service Set (abbreviated BSS, and also known as a base station or more colloquially, an access point) to another performed in a nearly seamless manner avoiding 802.1i 4 way handshake . 802.11r specifies transitions between access points by redefining the security key negotiation protocol, allowing both the negotiation and requests for wireless resources to occur in parallel. The key derived from the server to be cached in the wireless network, so that a reasonable number of future connections can be based on the cached key, avoiding the 802.1X process
ESP32 station supports FT for WPA2-PSK networks. Do note that ESP32 station only support FT over the air protocol only.
A config option CONFIG_ESP_WIFI_11R_SUPPORT and configuration parameter ft_enabled in wifi_sta_config_t is provided to enable 802.11r support for station. Refer ESP-IDF example examples/wifi/roaming/README.md for further details.
Attention
Distance measurement using RTT is not accurate, and factors such as RF interference, multi-path travel, antenna orientation, and lack of calibration increase these inaccuracies. For better results, it is suggested to perform FTM between two ESP32 chip series devices as station and AP.
Refer to ESP-IDF example examples/wifi/ftm/README.md for steps on how to set up and perform FTM.