ETA DAS Exam Study Guide (2026)
Everything the Distributed Antenna Systems (DAS) tests, topic by topic: what each section covers, the facts that come up most, and how to study it. Pair it with the free 15-question practice test.
The exam at a glance
| Questions | 75 multiple-choice questions |
|---|---|
| Time | 2 hours |
| Passing score | 75% |
| Format | Closed book; scratch paper and a non-programmable calculator are allowed. No hands-on exam is required for DAS |
| Certifying body | ETA International (Electronics Technicians Association), accredited by ICAC under ISO/IEC 17024 |
| Test provider | Any ETA Certification Administrator (test sites at schools, colleges and military bases), online through Trapeza or on paper, or remotely proctored through ETA's partner ExamRoom.AI for an extra fee |
Mind map: the whole exam on one screen
Read the complete ETA DAS study notes for “DAS Fundamentals and Types”
Our first full set of comprehensive notes, about 14 minutes of reading: What a DAS does · Types of DAS · Coverage and the life cycle · SISO and MIMO, a worked exam example, the traps examiners use and a one-minute recap. Create a free account to read it and see how premium notes work before you decide.
1. DAS Fundamentals and Types
ETA competency area 1.0 (1.1 to 1.3, 1.4.2.3): what a DAS is, active (hybrid fiber-coax, actives at the edge, twisted pair), BDA-fed passive and fully passive systems, in-building and outdoor DAS, wireless coverage, the DAS life cycle for public safety and cellular carriers, and SISO versus MIMO. ETA does not publish topic weights.
Key facts
- A distributed antenna system spreads radio signals from a source through a network of antennas to cover a building or area that a single site can't serve well.
- Passive DAS: coax, splitters, couplers and antennas fed by a BDA (off-air) or a base station; simple, but loss rises with distance and frequency.
- Active DAS: a head-end converts RF to optical or digital signals sent over fiber (or category cable) to powered remote units near the antennas; suits large, multi-carrier venues.
- Hybrid systems use fiber in the riser and coax on each floor; 'actives at the edge' put remote radios at each antenna, fed by fiber or Cat 6A.
- Coverage means usable signal strength and quality (for example RSRP and SINR, or DAQ for public safety) in the required share of the area.
- The DAS life cycle runs from survey and design through installation, commissioning, acceptance and ongoing maintenance and retesting; public safety systems add AHJ permits and annual tests.
- SISO uses one transmit and one receive path; MIMO uses multiple paths and antenna elements to carry parallel data streams, so a 2x2 MIMO DAS needs two paths per location.
Flashcards
Exam tip: Most type questions turn on scale and source: small building with off-air signal suggests a BDA; large multi-carrier site suggests active fiber DAS.
2. Spectrum, Radio Systems and FCC Rules
ETA competency areas 1.4 and 1.5: public safety bands under 47 CFR 90.20, simplex, half-duplex and trunked radio, uplink and downlink balance, cellular bands and technologies (GSM to 5G, FirstNet), and FCC rules for signal boosters (Part 90, section 90.219, consumer versus industrial boosters).
Key facts
- Public safety bands include VHF low (25 to 50 MHz), VHF high (150 to 174 MHz), UHF (450 to 470 MHz), T-band (470 to 512 MHz), 700 MHz narrowband and broadband, and 800 MHz (including NPSPAC), plus 4.9 GHz.
- FirstNet uses 700 MHz Band 14, about 758 to 768 MHz downlink and 788 to 798 MHz uplink.
- Simplex radios talk on one frequency; half-duplex uses separate transmit and receive frequencies through a repeater but one direction at a time; trunked systems share a pool of channels under a control channel.
- Downlink is from the network to the handset; uplink is from the handset to the network. A balanced system has matching downlink and uplink coverage.
- Cellular technologies: GSM (retired), CDMA/UMTS/WCDMA with HSPA, LTE and 5G NR.
- Under 47 CFR 90.219, signal boosters for Part 90 services need the express consent of the licensee, and the licensee remains responsible for interference.
- Class A boosters are channelized (narrow passband per channel); Class B boosters are broadband. Class B Part 90 boosters must be registered with the FCC.
- Consumer cellular boosters are a separate FCC category with their own limits; industrial boosters for multiple carriers need each carrier's consent.
Flashcards
Exam tip: For any booster scenario, ask two questions: does the licensee consent, and does the booster class match how close other users are?
3. Safety and RF Exposure
ETA competency area 2.0: OSHA requirements for in-building DAS work (PPE, seismic restraint, weather, lockout/tagout), RF safety and maximum permissible exposure under OSHA, FCC OET Bulletin 65 and IEEE C95.1-2019, and safe handling of fiber and fiber light sources.
Key facts
- OSHA enforces workplace safety: PPE, fall protection, ladders and lifts, and lockout/tagout control of hazardous energy.
- Equipment and racks in seismic zones need anchoring and bracing to the building per code.
- RF exposure limits are maximum permissible exposure (MPE) values; FCC OET Bulletin 65 gives evaluation methods and IEEE C95.1-2019 sets exposure criteria.
- Exposure is highest close to and in front of transmitting antennas; shut down or reduce power under a controlled procedure before working near them.
- Insulated gloves and distance from the side of an antenna are not RF protection.
- Fiber shards need safety glasses, a mat and a sealed container; never look into a fiber or optical port, as transmitters use invisible infrared light.
- On public safety systems, coordinate shutdowns with the monitoring company and AHJ because the fire alarm system supervises the ERCES.
Flashcards
Exam tip: RF safety answers favour removing the hazard (power down) over working around it. Picking 'stand to the side' is a common trap.
Test yourself on these topics
Take the free 15-question ETA DAS test, then save your results to unlock your Readiness Score and the mistakes bank.
4. Building Codes and Public Safety Requirements
ETA competency area 3.0: NFPA 72 Chapter 24, NFPA 1225 (2022, replacing NFPA 1221 and 1061), IFC Section 510, UL 2524, NEC, NESC and TIA-568 and 606-B; enclosures, alarms, battery backup, protected cable paths, coverage, testing, personnel requirements and AHJ code editions.
Key facts
- IFC Section 510 requires emergency responder radio coverage in buildings; NFPA 1225 Chapter 18 gives ERCES installation details. The AHJ decides which editions apply.
- Coverage: 95% of general building areas and 99% of critical areas (fire command center, fire pump rooms, exit stairs and passageways, elevator lobbies, areas the AHJ names).
Flashcards
Exam tip: Make one table of the public safety numbers (95/99%, -95 dBm, DAQ 3.0, 12 h, 20 dB isolation, NEMA 4, 2-hour) and drill it until automatic.
5. RF Signal Characteristics, Decibels and Noise
ETA competency area 4.0: coverage metrics (public safety RSSI and DAQ, SINR, BER, cellular RSSI, RSCP and RSRP), dB, dBm, dBd, dBi and dBc, the 3 dB rule, wavelength, amplitude, free space path loss, fading, multipath, reflection, absorption, diffraction, scattering, isolation and noise floor, noise figure and noise rise.
Key facts
- dB is a ratio; dBm is power relative to 1 mW (0 dBm = 1 mW, 30 dBm = 1 W); dBc is relative to a carrier.
- dBi is antenna gain over an isotropic radiator; dBd is over a dipole. dBi = dBd + 2.15.
Flashcards
Exam tip: Do every link calculation in dB: add gains, subtract losses, and keep antenna gains in dBi.
6. Site Surveys and DAS Equipment
ETA competency areas 5.0 and 6.0: choosing donor sites (distance and azimuth), confirming bands, donor signal measurement and interference mitigation, maximum uplink ERP, indoor RF characterization, equipment and antenna location, cable routing, plenum and riser spaces, DAS signal sources, passive and active DAS components, and Class A and Class B boosters.
Key facts
- The DAS owner or designer selects the donor site by measured signal, distance and azimuth; the donor antenna is usually a directional antenna on the roof aimed at it.
- Confirm all bands and channels of operation with the licensees before design.
Flashcards
Exam tip: Survey questions usually reward the step that protects the macro network: correct donor site, measured interference and limited uplink power.
7. Antennas, Transmission Lines and Passive Components
ETA competency area 7.0: donor and distribution antennas, antenna gain, coax, leaky (radiating) coax, fiber and twisted pair, bend radius, measurements (OTDR, return loss, baselines), connectors and cable preparation, splitters, couplers, tappers and hybrid combiners, cable support, connector weatherproofing, NEC-rated cable, firestopping and maintenance inspection.
Key facts
- Distribution antennas are typically low-gain omnidirectional ceiling antennas or directional panels for corridors and edges.
- Leaky (radiating) coax lets signal escape along its length; used in tunnels, garages and long corridors.
Flashcards
Exam tip: Keep a short list of splitter and coupler losses in your head; many power budget questions are just those numbers added up.
8. Installation, Commissioning, Testing and Troubleshooting
ETA competency areas 8.0 and 9.0: schematics, tools, Motorola R56 practices, PIM-aware antenna placement, grounding and bonding, mounting, test equipment, component installation, BOM and MOP, TIA-606-B labeling, commissioning (power up, baselines, isolation, gain and AGC, noise), sweep testing (return loss, insertion loss, distance-to-fault), PIM testing, coverage surveys, link budgets and grid testing.
Key facts
- Motorola Solutions R56 is a widely used standard for communication site grounding, bonding and installation; ground and bond equipment per the NEC with compression lugs.
- Test equipment includes DMM, spectrum analyzer, FDR cable sweeper, CW signal generator, communications service monitor, cellular survey tools, optical power meters and LAN testers.
Flashcards
Exam tip: Commissioning questions often hide an isolation calculation. Subtract 20 dB from the measured isolation to get the maximum gain.
How to pass
- 75 questions in 2 hours is 96 seconds each. Bring a non-programmable calculator and practise dB arithmetic: dBd to dBi, splitter and coupler losses, EIRP and isolation margins.
- ETA's competency list names specific codes: NFPA 1225 (which replaced NFPA 1221 and 1061), NFPA 72 Chapter 24, IFC Section 510, UL 2524, NEC, NESC, TIA-568 and TIA-606-B. Know what each one controls.
- Learn the public safety numbers by heart: 95% general and 99% critical-area coverage, -95 dBm and DAQ 3.0, 12-hour battery, isolation 20 dB above gain, NEMA 4 enclosures, 2-hour pathways.
- FCC rules are a favourite: licensee consent to rebroadcast, Part 90 and section 90.219, Class A versus Class B boosters, and who stays responsible for interference.
Frequently asked questions
How long should I study for the ETA DAS exam?
Most working candidates need 4 to 8 weeks at 45 to 60 minutes a day. Book your exam once your Readiness Score has stayed at 80 or higher for about a week.
Can I take the ETA DAS exam online?
BICSI's v15 handbook describes the RCDD exam at Pearson VUE test centers, not remote proctoring. Format: closed book; scratch paper and a non-programmable calculator are allowed. no hands-on exam is required for das. Check pearsonvue.com/bicsi for the options in your country.
What score do I need to pass the ETA DAS exam?
75%. The exam has 75 multiple-choice questions and a time limit of 2 hours.
What are the most tested topics?
The outline covers das fundamentals and types, spectrum, radio systems and fcc rules, safety and rf exposure, building codes and public safety requirements, rf signal characteristics, decibels and noise, site surveys and das equipment, antennas, transmission lines and passive components, installation, commissioning, testing and troubleshooting. Use the free practice test to see which ones you need most.
The premium ETA DAS study path
Premium ETA DAS prep is studied one topic at a time. Each step starts with that topic's key notes and flashcard deck, then its own question sets of 25, so you master one topic before you move to the next. When every topic is strong, the 6 full mock exams show you're ready.
Your step-by-step study path
- 1DAS Fundamentals and Types8 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Notes free with an account
- 2Spectrum, Radio Systems and FCC Rules8 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 3Safety and RF Exposure8 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 4Building Codes and Public Safety Requirements8 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 5RF Signal Characteristics, Decibels and Noise7 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 6Site Surveys and DAS Equipment7 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 7Antennas, Transmission Lines and Passive Components7 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 8Installation, Commissioning, Testing and Troubleshooting7 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- Final step: 6 full mock exams75 questions each, timed like test day. Pass them, then book your exam.Premium
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- 3,000 practice questions + 6 full mock exams per exam
- 800 flashcards + 60 key notes per exam, by topic, plus mind maps
- Spaced repetition + mistakes bank
- Readiness Score & detailed reports
- Video lessons as they release
- Content updates during your access
- 5 bonuses: numbers and formulas sheet, standards atlas, study planner and more
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Renews once a year until you cancel. We email you before each renewal. Cancel any time from your account; you keep access until the end of the year you've paid for.
Summarized from BICSI's official candidate information and the rules cited, checked October 2026. Confirm current requirements with ETA International (Electronics Technicians Association), accredited by ICAC under ISO/IEC 17024.