14.3.6.1 Overview
A CCA measurement is used to detect a clear channel. Four CCA modes are specified by IEEE 802.15.4-2006:
CCA Mode | Description |
---|---|
1 |
Energy above threshold. CCA shall report a busy medium upon detecting any energy above the ED threshold. |
2 |
Carrier sense only. CCA shall report a busy medium only upon the detection of a signal with the modulation and spreading characteristics of an IEEE 802.15.4 compliant signal. The signal strength may be above or below the ED threshold. |
0, 3 |
Carrier sense with energy above threshold. CCA shall report a busy medium using a logical combination of
Where the logical operator may be configured as either OR (mode 0) or AND (mode 3). |