Are you experiencing problems establishing a Miracast connection or does the connection drop frequently? A common cause is the use of DFS channels (Dynamic Frequency Selection) on the Wi-Fi network. In this article, we explain why this affects Miracast.
What is DFS and why does it interfere with Miracast?
Wi-Fi on the 5GHz band shares certain frequencies with radar systems (such as aviation and weather radars). These shared frequencies are called DFS channels.
- The DFS ranges:
- 5250 – 5350 MHz (Channels 52 to 64)
- 5470 – 5725 MHz (Channels 100 to 140)
When a router transmits on a DFS channel, it is legally required to immediately vacate the frequency if a radar signal is detected. Because Miracast creates a direct "peer-to-peer" connection via your Wi-Fi adapter, the connection conflicts with these scanning protocols. Many Miracast receivers simply do not support DFS channels to keep connections stable.
To resolve this, the channels in the router or access point must be adjusted. Select one of the following 'free' channels (UNII-1 band): 36, 40, 44 or 48. Channels above 144 (if available) are often also DFS-free, but channels 36 to 48 offer the widest compatibility with virtually all Miracast equipment.