Espressif Systems ESP Faq page 165

Chapter 4. Software framework
4.10.107 How to configure the Wi-Fi country code when the ESP end product needs to be
sold worldwide?
• Different Wi-Fi country codes need to be set for different countries.
• The default country code configuration can be used for most countries, but it is not compatible
with some special cases. The default country code is CHINA {.cc="CN", .schan=1,
.nchan=13, policy=WIFI_COUNTRY_POLICY_AUTO}. While in the ESP-IDF v5.0 or
later version, the dafualt one has been changed to "01" (world safe mode) {.cc="01",
.schan=1, .nchan=11, .policy=WIFI_COUNTRY_POLICY_AUTO}） . Since chan-
nels 12 and 13 are passively scanned by default, they do not violate the regulations of most coun-
tries. Besides, the country code of the ESP product is automatically adapted to the router that
it is connected to. When disconnected from the router, it automatically goes back to the default
country code.
Note:
• There is a potential issue.
the ESP end product can not scan the router.
icy=WIFI_COUNTRY_POLICY_MANUAL to enable ESP end products to actively scan on chan-
nels 12 and 13.
• Some countries, such as Japan, support channels 1-14, and channel 14 only supports 802.11b. ESP
end products cannot connect to routers on channel 14 by default.
4.10.108 Sometimes the rate drops or even a disconnection occurs after a period of iperf
testing. What is the reason and how to solve it?
• Possible reasons:
– Bad network environment.
– Incompatibility between the computer or mobile phone and the ESP32-S2 or ESP32-S3 sof-
tAP.
• Solutions:
– In the case of a bad network environment, change the network environment or test in a shielded
box.
– In the case of incompatibility, disable menuconfig > Component config > Wi-Fi >
WiFi AMPDU RX. If disconnections occur again, disable menuconfig > Component
config > Wi-Fi > WiFi AMPDU TX.
Note:
• AMPDU stands for Aggregated MAC Protocol Data Unit and is a technique used in the IEEE
802.11n standard to increase network throughput.
• When WiFi AMPDU RX is disabled, the device will not receive AMPDU packets, which will
affect the RX performance of the device.
• When WiFi AMPDU TX is disabled, the device will not send AMPDU packets, which will affect
the TX performance of the device.
4.10.109 Why is this log frequently printed when the phone connects to the ESP32-S3
that works as the Wi-Fi AP based on the ESP-IDF v5.0 SDK?
Espressif Systems
If the router hides the SSID and is on channel 12 or 13,
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In this case, you need to set pol-
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