Data Sheet

3.5 Wi-Fi 3 FUNCTIONAL DESCRIPTION
• Antenna diversity and selection (software-managed hardware)
3.5.2 Wi-Fi MAC
The ESP32 Wi-Fi MAC applies low level protocol functions automatically as follows:
• Request To Send (RTS), Clear To Send (CTS) and Acknowledgement (ACK/BA)
• Fragmentation and defragmentation
• Aggregation AMPDU and AMSDU
• WMM, U-APSD
• 802.11 e: QoS for wireless multimedia technology
• CCMP (CBC-MAC, counter mode), TKIP (MIC, RC4), WAPI (SMS4), WEP (RC4) and CRC
• Frame encapsulation (802.11h/RFC 1042)
• Automatic beacon monitoring/scanning
3.5.3 Wi-Fi Firmware
The ESP32 Wi-Fi Firmware provides the following functions:
• Infrastructure BSS Station mode / P2P mode / softAP mode support
• P2P Discovery, P2P Group Owner, P2P Group Client and P2P Power Management
• WPA/WPA2-Enterprise and WPS driver
• Additional 802.11i security features such as pre-authentication and TSN
• Open interface for various upper layer authentication schemes over EAP such as TLS, PEAP, LEAP, SIM,
AKA or customer specific
• Clock/power gating combined with 802.11-compliant power management dynamically adapted to current
connection condition providing minimal power consumption
• Adaptive rate fallback algorithm sets the optimal transmission rate and transmit power based on actual Signal
Noise Ratio (SNR) and packet loss information
• Automatic retransmission and response on MAC to avoid packet discarding on slow host environment
3.5.4 Packet Traffic Arbitration (PTA)
ESP32 has a configurable Packet Traffic Arbitration (PTA) that provides flexible and exact timing Bluetooth co-
existence support. It is a combination of both Frequency Division Multiplexing (FDM) and Time Division Multiplexing
(TDM), and coordinates the protocol stacks.
• It is preferable that Wi-Fi works in the 20 MHz bandwidth mode to decrease its interference with BT.
• BT applies AFH (Adaptive Frequency Hopping) to avoid using the channels within Wi-Fi bandwidth.
• Wi-Fi MAC limits the time duration of Wi-Fi packets, and does not transmit the long Wi-Fi packets by the
lowest data-rates.
• Normally BT packets are of higher priority than normal Wi-Fi packets.
• Protect the critical Wi-Fi packets, including beacon transmission and receiving, ACK/BA transmission and
receiving.
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