Free Distributed Antenna Systems Installer (DASI) Practice Questions

Sample Practice Questions

Try these 10 sample questions from the Distributed Antenna Systems Installer (DASI) practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1What makes an antenna arrangement a distributed antenna system?

   1. A.Independent antennas each serve a separate radio network.
   2. B.Separated antenna nodes share a source through a distribution medium.Correct answer: B
   3. C.One centrally located antenna serves the entire coverage area.
   4. D.A point-to-point antenna pair connects two radio sites.

   Explanation: The FCC defines a DAS as "A network of spatially separated antenna nodes connected to a common source via a transport medium". The connected antennas distribute a common wireless service across the intended coverage area.

   Reference: 47 CFR § 90.219 — Use of signal boosters — 47 CFR 90.219(a), Distributed Antenna System (DAS)

2. 2Under OSHA's general-industry PPE rule, what should determine the protective equipment selected for DAS maintenance work?

   1. A.The standard PPE kit assigned to everyone with that job title
   2. B.The hazards identified for the actual tasks in the workplaceCorrect answer: B
   3. C.The PPE used on a previous task with different exposure conditions
   4. D.The least protective kit that allows the task to be completed

   Explanation: OSHA requires PPE against "the hazards identified in the hazard assessment". Select protection for the actual work hazards; a job-title kit, a different task’s assessment, or a minimally obstructive kit does not establish suitable protection.

   Reference: 29 CFR § 1910.132 — General requirements for personal protective equipment — § 1910.132(d)(1)(i)

3. 3Which two standards were consolidated into NFPA 1225-2022?

   1. A.NFPA 70 and NFPA 72
   2. B.NFPA 1 and NFPA 101
   3. C.NFPA 1221 and NFPA 1061Correct answer: C
   4. D.NFPA 780 and NFPA 70E

   Explanation: ETA identifies "NFPA 1221 and NFPA 1061" as the standards consolidated by NFPA 1225-2022, distinct from electrical, signaling, and lightning-protection standards.

   Reference: Distributed Antenna Systems Installer Competency Requirements — Page 2, competency 3.1.2.1

4. 4Which coverage measurement indicates received signal strength rather than speech intelligibility or digital error performance?

   1. A.DAQ
   2. B.RSSICorrect answer: B
   3. C.FBER
   4. D.SINR

   Explanation: PCTEL identifies "RSSI / signal strength". DAQ assesses speech, FBER digital errors, and SINR signal quality relative to interference and noise.

   Reference: Public Safety Tester Training — Coverage Testing Overview — Section 17, Common measurements

5. 5Before aiming a donor antenna, how should the installer establish which tower is the intended donor?

   1. A.Use the nearest tower with a clear visible path.
   2. B.Use the tower giving the highest measured signal of any service.
   3. C.Confirm the intended agency donor with the responsible radio authority.Correct answer: C
   4. D.Use the tallest tower in the local coverage area.

   Explanation: Comba requires checking the "correct tower" with the AHJ or communications authority. Distance, height, and strong unrelated signals do not establish the intended public safety donor.

   Reference: Commissioning a BDA — A Walkthrough Guide, Part I — Part 2, Step 1, Verify Donor Tower Location

6. 6Which arrangement supplies a DAS from an off-air source?

   1. A.Receiving the serving network through an external donor antennaCorrect answer: A
   2. B.Connecting a dedicated optical feed directly from the network
   3. C.Connecting an onsite base station through a direct RF cable
   4. D.Injecting a locally generated commissioning test carrier

   Explanation: UFC describes off-air sourcing as using "an external donor antenna to capture cellular signals from local cell towers." The same antenna-fed sourcing principle distinguishes an off-air radio feed from direct wired network or test-generator feeds.

   Reference: Information and Communications Technology Infrastructure Planning and Design — § 2-3.5.4.15, Cellular Coverage, page 51

7. 7Which antenna is a directional array suited to aiming toward one designated donor site?

   1. A.A vertical omnidirectional collinear
   2. B.A quarter-wave ground-plane antenna
   3. C.A Yagi arrayCorrect answer: C
   4. D.An isotropic reference radiator

   Explanation: CISA lists "corner reflectors", "Yagi antennas", and "parabolic dishes" as directional types. A Yagi focuses the donor link toward a selected direction; an omnidirectional pattern serves azimuths around the antenna, and an isotropic radiator is a reference.

   Reference: All-Hazards Communications Technician Pre-Course Study Guide — Study 5, Types of Antennas, guide page 92

8. 8Which drawing view is most useful for checking where DAS cabinets fit in an equipment room and whether their working clearances are allocated?

   1. A.A circuit wiring schematic
   2. B.A vertical cable-riser diagram
   3. C.An equipment-room plan viewCorrect answer: C
   4. D.A front-of-rack equipment elevation

   Explanation: UFC calls for "telecommunication rooms plan views" to allocate equipment space and working clearances. A plan view shows room geometry; a wiring schematic, riser diagram, or rack elevation cannot by itself establish floor-plan clearance.

   Reference: Information and Communications Technology Infrastructure Planning and Design — Table 2-2, Required Drawings, T3DD, page 5

9. 9Two otherwise identical antenna paths measure 10 dB and 20 dB return loss. Which path reflects the smaller fraction of incident power?

   1. A.The 10 dB path, reflecting 1%
   2. B.The 20 dB path, reflecting 1%Correct answer: B
   3. C.The 10 dB path, reflecting 10%
   4. D.The 20 dB path, reflecting 10%

   Explanation: The source states "only 1% of the power is returned". At 20 dB return loss, reflected power is 1%; at 10 dB, it is 10%. Higher positive return loss therefore indicates the better match.

   Reference: Understanding Cable and Antenna Analysis — section 3.0, Return Loss / VSWR

10. 10An approved DAS cable route changed during installation. What should its as-built drawing show?

    1. A.The original bid route regardless of actual work
    2. B.The actual installed route and configurationCorrect answer: B
    3. C.The shortest route proposed for a future project
    4. D.Only the cable manufacturer’s standard installation diagram

    Explanation: The specification states "Ensure that these drawings and documents depict the as-built configuration.". As-built records describe the completed installation. Leaving an obsolete planned route makes them unreliable for maintenance.

    Reference: Building Telecommunications Cabling System — section 1.11.1, Operation and Maintenance Manuals