thinQmaster Virtual testing partner Adaptive practice exams that find your weak spots and drill them. Every answer explained. From $69
Enroll

thinQmaster

Find your exam

Five questions free, before you decide.

Step 1 · choose a vendor

In one of our camps? Your practice exams come with the tuition — they are on your study page already.

Wireless & Mobility · Advanced

Energy Detect (ED)

The CCA method that marks the medium busy when any RF energy exceeds a threshold, even if undecodable.

Definition

Energy detect lets Wi-Fi defer to non-Wi-Fi signals or undecodable Wi-Fi. Its threshold is typically 20 dB above signal detect, around -62 dBm for 20 MHz. Strong non-Wi-Fi interference can block transmission through ED.

Exam tip

Energy detect responds to non-Wi-Fi energy; signal detect requires a valid preamble.

Related terms