NCTI Business Services for Technicians Practice Test 2025 - Free Practice Questions and Study Guide

In the 5GHz frequency band, certain segments are designated as DFS (Dynamic Frequency Selection) channels, which are important for mitigating interference with radar systems. The correct response identifies the UNII-2 and UNII-2e bands as those that contain DFS channels.

The UNII-2 band comprises various channels including DFS channels, which enables routers and access points to operate effectively while avoiding radar interference. The UNII-2e band is an extension of this and also includes additional DFS channels. This dual-band capability aligns with regulations that seek to use these channels while maintaining coexistence with radar systems.

Other bands, such as UNII-1 and UNII-3, do not contain DFS channels. UNII-1 primarily consists of non-DFS channels, while UNII-3 includes both non-DFS and standard channels but lacks the specific designation for DFS associated with UNII-2 and UNII-2e. Thus, the identification of UNII-2 and UNII-2e as containing the DFS channels is accurate, reflecting the designated usage as per IEEE and regulatory guidelines.