Communications (IB-PSC) – Design Track
Practice Exam Design Level – Questions
And Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant
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1. What is the primary purpose of a public safety DAS?
A. To provide entertainment broadcasts
B. To provide cellular service to private users
C. To ensure reliable radio communications for first responders
within buildings
D. To increase Wi-Fi coverage in buildings
Public safety DAS is designed to ensure first responders have
reliable radio communications inside buildings, independent of
commercial cellular coverage.
2. Which frequency band is commonly used for public safety radio
communications in the U.S.?
A. 450–470 MHz
B. 700/800 MHz
C. Both A and B
D. 2.4 GHz
Public safety radio systems in the U.S. operate in several bands
including 450–470 MHz (VHF/UHF) and 700/800 MHz.
,3. What is the minimum signal strength generally required at the
edge of a building for public safety radio coverage?
A. -95 dBm
B. -95 dBm to -85 dBm
C. -65 dBm
D. -50 dBm
Design standards typically specify a minimum signal level between
-95 dBm and -85 dBm to ensure reliable communications.
4. Which of the following is the most common method for
distributing RF signals inside a building?
A. Fiber-optic backbone only
B. Distributed Antenna System (DAS)
C. Microwave links
D. Satellite repeaters
A DAS uses multiple antennas distributed throughout a building to
ensure adequate coverage.
5. What is the role of a bi-directional amplifier (BDA) in a public
safety DAS?
A. Converts analog signals to digital
B. Amplifies signals in both uplink and downlink directions
C. Monitors building fire alarms
D. Provides Wi-Fi service
BDAs amplify weak radio signals from the outside and inside to
ensure adequate coverage throughout the building.
6. Which document is typically referenced for NFPA standards for
public safety communications in buildings?
A. NFPA 72
B. NFPA 101
C. NFPA 1221
, D. NFPA 70
NFPA 1221 provides requirements for the installation,
performance, and maintenance of emergency communications
systems.
7. Which factor is most critical when designing DAS antenna
placement?
A. Ceiling color
B. Path loss and building materials
C. Distance to nearest fire exit
D. Number of Wi-Fi users
Building materials like concrete, metal, and glass affect RF signal
propagation and must be considered.
8. What type of DAS is designed to serve a single carrier?
A. Hybrid DAS
B. Passive DAS
C. Active DAS
D. Neutral-host DAS
Active DAS uses powered components to distribute signals for a
single carrier or public safety system.
9. Which of the following best describes a neutral-host DAS?
A. Supports only cellular carriers
B. Supports multiple carriers and public safety systems
C. Is limited to Wi-Fi signals
D. Requires fiber-optic connections only
Neutral-host DAS allows multiple service providers and public
safety radios to share the same infrastructure.
10. Which of these is a primary consideration for DAS power
design?
A. Lighting in the building