CWNA Regulatory Frameworks & Compliance 4 — Questions and Answers
Question 1: What is the minimum channel availability check (CAC) time required before a Wi-Fi device can transmit on a DFS channel?
- 60 seconds (Correct answer)
- 10 seconds
- 30 seconds
- 5 minutes
Correct answer: 60 seconds
FCC rules require a 60-second Channel Availability Check before an 802.11 device begins transmitting on a DFS channel.
Question 2: An enterprise is importing Wi-Fi access points from a foreign manufacturer. Which mark must US-bound units carry before sale?
- FCC ID label (Correct answer)
- CE mark
- RCM mark
- TELEC mark
Correct answer: FCC ID label
Radio devices sold in the US must display an FCC ID, issued after the device has been authorized through the equipment authorization process.
Question 3: Under FCC Part 15.407, low-power indoor (LPI) devices in the 6 GHz band are restricted to what maximum EIRP?
- 30 dBm (1 W) (Correct answer)
- 36 dBm (4 W)
- 23 dBm (200 mW)
- 20 dBm (100 mW)
Correct answer: 30 dBm (1 W)
FCC Part 15.407 permits LPI 6 GHz devices up to 30 dBm EIRP when operating indoors without automated frequency coordination.
Question 4: What is the purpose of Automated Frequency Coordination (AFC) for standard power devices in the 6 GHz band?
- Ensure standard power devices do not interfere with fixed microwave and satellite incumbents (Correct answer)
- Automatically select the least congested 6 GHz channel for outdoor use
- Coordinate transmit power between neighboring access points
- Provide dynamic spectrum access for indoor Wi-Fi 6E devices
Correct answer: Ensure standard power devices do not interfere with fixed microwave and satellite incumbents
AFC systems query a geospatial database to determine which 6 GHz channels and power levels are safe for standard power outdoor devices near licensed incumbents.
Question 5: Which regulatory document defines how Wi-Fi equipment must be tested to verify compliance with FCC limits?
- KDB (Knowledge Database) publication procedures (Correct answer)
- RFC published by the IETF
- IEEE 802.11 specification annex
- ETSI EN 301 893
Correct answer: KDB (Knowledge Database) publication procedures
The FCC's Knowledge Database (KDB) provides detailed test procedures and Q&A guidance that equipment must follow to receive FCC authorization.
Question 6: A wireless network causes interference to a neighbor's licensed microwave link. Under FCC rules, who bears the primary responsibility to resolve the interference?
- The unlicensed Part 15 operator must cease operation or fix the interference (Correct answer)
- The licensed microwave operator must adjust its equipment to accept co-channel interference
- Both operators share equal legal responsibility to resolve the issue
- The FCC must mediate and assign new frequencies to both parties
Correct answer: The unlicensed Part 15 operator must cease operation or fix the interference
FCC Part 15 explicitly states that unlicensed devices must accept harmful interference and must not cause harmful interference to licensed services.
Question 7: Which Wi-Fi Alliance certification program validates interoperability and security compliance for 802.11ax devices?
- Wi-Fi CERTIFIED 6 (Correct answer)
- IEEE 802.11ax Mark
- FCC Part 15 Class B
- WPA3-Enterprise
Correct answer: Wi-Fi CERTIFIED 6
Wi-Fi CERTIFIED 6 (and 6E/6 GHz variants) is the Wi-Fi Alliance's interoperability certification for 802.11ax devices.
CWNA Regulatory Frameworks & Compliance 4
What is the minimum channel availability check (CAC) time required before a Wi-Fi device can transmit on a DFS channel?