C3DNA contains affiliate links and is a member of the Amazon Services LLC Associates Program. If you make a purchase using one of these links, we may receive compensation at no extra cost to you. This helps support our research, testing and writing.

FCC Rules: What Frequencies You Can Transmit On

by

The Federal Communications Commission (FCC) regulates all radio frequency transmissions in the United States, allocating specific frequency bands for different services and establishing power limits, technical requirements, and licensing rules. Understanding which frequencies you can legally transmit on—whether for amateur radio, business communications, personal use, or experimental purposes—prevents violations that can result in substantial fines ($10,000+ per violation), equipment confiscation, and criminal penalties for willful or repeated infractions.

Understanding FCC Frequency Allocations

The radio spectrum spans from 3 kHz to 300 GHz, divided into bands allocated for specific services: AM/FM broadcasting, television, cellular communications, aviation, maritime, military, amateur radio, satellite services, and unlicensed devices. The FCC’s Table of Frequency Allocations (Part 2.106) details which services may operate in each frequency range, whether operation requires individual licenses or falls under general authorization, and technical parameters governing transmissions.

Critical concept: The FCC distinguishes between (1) licensed services requiring individual station licenses after examination, application, and fee payment (amateur radio, commercial broadcast, land mobile radio), (2) licensed-by-rule services where purchasing type-accepted equipment constitutes authorization (CB radio, FRS radios, WiFi routers), and (3) unlicensed/Part 15 devices operating under strict power and interference limits without individual authorization. Transmitting on frequencies outside your authorization, exceeding power limits, or using non-certified equipment constitutes illegal operation subject to FCC enforcement action regardless of intent or awareness.

Unlicensed Frequency Bands (Part 15)

ISM Bands and General Unlicensed Use

The FCC designates Industrial, Scientific, and Medical (ISM) bands for unlicensed operation under Part 15 rules, allowing operation without individual licenses if equipment is FCC-certified and power limits are observed.

Primary ISM/Unlicensed Bands:

902-928 MHz (33cm band):

  • Power limit: 1 watt EIRP (Equivalent Isotropically Radiated Power) for spread spectrum
  • Applications:
    • Cordless phones
    • Baby monitors
    • Wireless home automation (Z-Wave, Insteon)
    • Industrial sensors
    • Some amateur radio equipment (shared allocation)
  • Range: Typically 100-300 feet depending on environment
  • Interference: Must accept interference from all sources
  • Shared with amateur radio (33cm band), who have priority

2.4-2.4835 GHz (2.4 GHz band):

  • Power limit: 1 watt conducted power + antenna gain up to 36 dBm EIRP
  • Most heavily used unlicensed band
  • Applications:
    • WiFi (802.11b/g/n/ax)
    • Bluetooth devices
    • Cordless phones
    • Microwave ovens (unintentional radiators)
    • Wireless cameras
    • RC cars and drones
    • Zigbee home automation
  • 14 channels in WiFi (only channels 1, 6, 11 non-overlapping)
  • Extremely congested in urban areas
  • Must tolerate interference (no protection)

5.725-5.850 GHz (5.8 GHz upper band):

  • Power limit: 1 watt conducted power, higher EIRP allowed with directional antennas
  • Applications:
    • WiFi (802.11a/n/ac/ax)
    • Cordless phones
    • Wireless video links
    • Point-to-point data links
  • Less congested than 2.4 GHz
  • Shorter range (higher frequency = more attenuation)
  • Additional 5 GHz bands: 5.15-5.35 GHz and 5.47-5.725 GHz (DFS channels, dynamic frequency selection required to avoid radar)

433 MHz (Europe/International, limited US use):

  • Not a primary ISM band in US
  • Some imported devices operate here
  • Technically illegal for intentional radiators without certification
  • Amateur radio band (70cm) includes this frequency

60 GHz (57-64 GHz):

  • Very high frequency, short range
  • Applications:
    • WiGig (802.11ad/ay)
    • Wireless HDMI
    • Point-to-point links
  • Oxygen absorption at 60 GHz limits range (security benefit)
  • Power limits: 40 dBm EIRP (10 watts)

Part 15 General Rules:

  1. Must use certified equipment:
    • FCC ID label required on device
    • Cannot modify transmitter section
    • Homebrew transmitters generally prohibited
  2. Power limits strictly enforced:
    • Field strength limits at specific distances
    • Antenna gain restrictions
    • Must not cause harmful interference
  3. No interference protection:
    • Must accept all interference received
    • Must immediately cease operation if causing harmful interference to licensed services
  4. Antenna restrictions:
    • Fixed antennas only for some applications
    • Removable antennas must use unique connectors (no standard SMA)
    • Professional installation required for outdoor high-gain installations

WiFi and Wireless Networking (Part 15.247)

2.4 GHz WiFi (802.11b/g/n/ax):

  • Channels 1-11 in US (channels 12-14 prohibited)
  • Power limits:
    • Indoor: 1 watt (30 dBm) conducted power
    • Outdoor point-to-point: Higher power allowed with directional antennas
    • Commercial installations: Professional installer requirements
  • Most routers default to compliant power levels
  • Illegal modifications:
    • Increasing transmit power beyond limits
    • Using amplifiers without proper certification
    • DD-WRT/OpenWRT firmware must maintain FCC compliance

5 GHz WiFi (802.11a/n/ac/ax):

  • Multiple sub-bands with different rules:
    • U-NII-1 (5.15-5.25 GHz): Indoor only, 1 watt conducted
    • U-NII-2A (5.25-5.35 GHz): Indoor/outdoor, DFS required, 1 watt
    • U-NII-2C (5.47-5.725 GHz): Indoor/outdoor, DFS required, 1 watt
    • U-NII-3 (5.725-5.850 GHz): Indoor/outdoor, no DFS, higher power allowed
  • DFS (Dynamic Frequency Selection): Router must detect and avoid radar
  • TPC (Transmit Power Control): Automatic power reduction
  • Outdoor use: U-NII-3 most reliable (no DFS requirement)

WiFi 6E (6 GHz band: 5.925-7.125 GHz):

  • Newest allocation (2020)
  • 1200 MHz of spectrum (double previous WiFi allocation)
  • Low-power indoor: Typical consumer use
  • Standard-power: Access points with automatic frequency coordination (AFC)
  • Very low-power: Wearables and IoT devices
  • Minimal congestion (new band)

Bluetooth and Short-Range Devices

Bluetooth (2.4 GHz):

  • Operates in 2.4-2.4835 GHz ISM band
  • Frequency hopping spread spectrum (FHSS)
  • Power classes:
    • Class 1: 100 mW (20 dBm) – range ~300 feet
    • Class 2: 2.5 mW (4 dBm) – range ~30 feet (most common)
    • Class 3: 1 mW (0 dBm) – range ~3 feet
  • Bluetooth 5: Enhanced range and data rates
  • Mesh networking capabilities
  • Must use certified Bluetooth modules (no homebrew)

Other Short-Range Unlicensed Devices:

  • Garage door openers: 300-400 MHz range
  • Wireless doorbells: Various frequencies (315 MHz, 433 MHz common)
  • RFID tags: 125 kHz (LF), 13.56 MHz (HF), 900 MHz (UHF)
  • Wireless car keys: 315 MHz, 433 MHz, 900 MHz
  • Medical implants: 402-405 MHz (MICS band)

Compliance requirements:

  • All devices must be FCC certified (FCC ID label)
  • Cannot modify transmitter sections
  • Must accept all interference
  • Immediately cease operation if causing harmful interference

Citizens Band (CB) Radio – Part 95A

CB Radio Service

CB radio represents one of the oldest unlicensed radio services, requiring no examination or license but with strict technical rules.

Frequency allocation:

  • Band: 26.965-27.405 MHz (11-meter band)
  • Channels: 40 channels, 10 kHz spacing
  • Channel 9: Emergency communications (monitored by volunteers)
  • Channel 19: Truckers’ channel (highway information)
  • AM mode: Traditional, most common
  • SSB (Single Sideband): Allowed, greater range, channels 36-40 typically used

Power limits:

  • AM mode: 4 watts carrier power (12 watts PEP)
  • SSB mode: 12 watts peak envelope power (PEP)
  • Measurement: At transmitter output (not EIRP)
  • External amplifiers: Illegal (major FCC enforcement focus)

Equipment requirements:

  • Must use FCC-certified CB radios (FCC ID or DOC number)
  • No homebrew transmitters
  • No modifications to increase power
  • Type-accepted antennas (though rarely enforced for mobile use)

Operational rules:

  • No obscene, indecent, or profane language
  • Communications must be brief (5 minutes maximum per transmission)
  • Must ID with callsign “unit number” or name
  • Business use allowed (limited scope)
  • No encryption or codes to obscure meaning
  • Cannot cause harmful interference

Antenna restrictions:

  • Height limit: 20 feet above structure for fixed stations
  • Mobile antennas: No restriction (practical limits apply)
  • Directional antennas allowed
  • Gain limits (implicit in power measurement at antenna input)

Common CB violations:

  • Linear amplifiers: Possessing or operating RF amplifiers designed for 11-meter band (illegal per se, even if not connected)
  • Excessive power: Operating above 12W PEP
  • Continuous transmission: “Dead key” transmissions without modulation
  • Interference: Operating with harmonics or spurious emissions
  • International communication: Prohibited except Canada/Mexico border areas

Enforcement:

  • FCC actively pursues illegal CB amplifier sales
  • Direction finding for intentional interference (“jammers”)
  • Fines: $10,000+ for amplifier possession/operation
  • Equipment forfeiture common

Family Radio Service (FRS) – Part 95B

FRS provides short-range, license-free communications for personal and family use.

Frequency allocation:

  • Channels: 22 channels in 462 and 467 MHz range (UHF)
  • Shared with GMRS (General Mobile Radio Service) on some channels
  • Channel 1-7, 15-22: FRS exclusive or shared
  • Channel 8-14: Shared with GMRS (lower power on FRS)

Power limits:

  • Channels 1-7, 15-22: 2 watts maximum
  • Channels 8-14: 0.5 watts maximum (shared with GMRS)
  • Removable antennas prohibited (permanent antennas only)
  • Range: Typically 0.5-2 miles depending on terrain

Equipment requirements:

  • Must use FCC-certified FRS radios
  • Fixed, non-removable antennas
  • Cannot modify radios
  • Common brands: Motorola Talkabout, Midland, Cobra

Operational rules:

  • No license required
  • Personal or business use allowed (local, short-range)
  • Cannot relay communications (repeater use prohibited)
  • Recreation, outdoor activities, family communications
  • CTCSS/DCS privacy codes allowed (do not provide security, only squelch)

FRS vs. GMRS:

  • FRS: No license, lower power, fixed antennas
  • GMRS: License required ($35/10 years), higher power, removable antennas, repeater access
  • Many “bubble pack” radios labeled “FRS/GMRS” now FRS-only (post-2017 rule changes)

General Mobile Radio Service (GMRS) – Part 95E

GMRS requires an FCC license but no examination, offering higher power and repeater access for family communications.

Licensing:

  • License type: Individual license
  • Cost: $35 (10-year term, effective 2021 reduction)
  • No exam required
  • Coverage: Licensee and immediate family members
  • Application: FCC Universal Licensing System (ULS) online
  • Callsign: Issued automatically (WRAE format)

Frequency allocation:

  • Channels: 30 channels (462 and 467 MHz)
  • Main channels: 1-22 (shared with FRS on some)
  • Repeater inputs: 467 MHz (channels 15-22)
  • Repeater outputs: 462 MHz (channels 15-22)
  • Interstitial channels: 8 additional channels between main channels

Power limits:

  • Handheld: Up to 5 watts
  • Mobile/base: Up to 50 watts on main channels
  • Repeater channels: 50 watts
  • Specific channels have specific limits (see FCC Part 95 for details)

Equipment requirements:

  • Must use FCC-certified GMRS radios (FCC ID required)
  • Removable antennas allowed (unlike FRS)
  • Cannot modify certified radios
  • Popular radios: Midland GMRS, Motorola GMRS, Baofeng GMRS (some models)

Repeaters:

  • GMRS repeaters allowed (require license)
  • Channels 15-22 designated for repeater use
  • 5 MHz offset (462 MHz transmit, 467 MHz receive or vice versa)
  • CTCSS/DCS tones commonly required for repeater access
  • Many open repeaters available (check mygmrs.com)
  • Closed repeaters require permission from licensee

Operational rules:

  • Station identification required (callsign)
  • ID at beginning and end of exchange, every 15 minutes during
  • Family members use licensee’s callsign + identifier (e.g., “WRAE123 unit 2”)
  • Personal, family, business communications allowed
  • No music, advertising, or broadcasting
  • No encryption (except for remote control of devices)

Advantages over FRS:

  • Higher power (50W vs. 2W)
  • Removable/external antennas
  • Repeater access (greatly extends range)
  • Mobile and base station use
  • Better radios available

Range:

  • Handheld to handheld: 2-5 miles typical
  • Mobile/base: 10-20 miles typical
  • With repeater: 20-50+ miles possible
  • Terrain and antenna height dominate range

Amateur Radio Service (Ham Radio) – Part 97

Licensing and Privileges

Amateur radio offers the most extensive frequency privileges for unlicensed individuals, but requires passing written examinations demonstrating technical and regulatory knowledge.

License classes:

Technician Class:

  • Entry-level license
  • Exam: 35 questions (multiple choice)
  • Passing score: 26 correct (74%)
  • No Morse code requirement (eliminated 2007)
  • Privileges:
    • All amateur frequencies above 30 MHz (VHF/UHF/microwave)
    • Limited HF privileges (portions of 10m, 15m, 40m, 80m bands)
    • CW (Morse code) on all HF bands
    • 1500 watts PEP maximum (except specific band limits)
  • Cost: Exam fee ~$15 (set by Volunteer Examiner)

General Class:

  • Intermediate license (requires Technician)
  • Exam: 35 questions (in addition to Technician)
  • Passing score: 26 correct
  • Privileges:
    • Most HF band privileges
    • SSB voice on HF bands (long-distance communication)
    • Digital modes on HF
    • All Technician privileges retained
    • Worldwide communication capability

Amateur Extra Class:

  • Highest license class
  • Exam: 50 questions (in addition to General)
  • Passing score: 37 correct (74%)
  • Privileges:
    • All amateur radio frequencies and modes
    • Exclusive Extra-class band segments (less crowded)
    • Access to most DX frequencies
    • Prestige and recognition

Call signs:

  • Issued by FCC automatically after passing exam
  • Format varies by license class:
    • Technician: Usually 2×3 format (e.g., KE7XYZ)
    • General: Can request 1×3 or 2×2 (e.g., W7XY, AB7XY)
    • Extra: Can request 1×2 or 2×1 (e.g., K7XY, W7X)
  • Vanity callsigns available (request specific call if available)

License term:

  • 10 years
  • Renewable online (no re-examination)
  • Free renewal
  • Grace period: 2 years after expiration to renew

Amateur Radio Frequency Bands

Amateur radio has allocations across the radio spectrum, from LF to microwaves, with different propagation characteristics and uses.

HF (High Frequency) Bands – Long Distance:

160 meters (1.8-2.0 MHz):

  • Privileges: All classes (CW), General/Extra (voice)
  • Propagation: Nighttime, regional to continental
  • Uses: Ragchewing, contests, DX (long-distance)
  • Power: 1500W PEP max
  • Characteristics: Large antennas required, noise floor high

80 meters (3.5-4.0 MHz):

  • Privileges: Technician (CW only, 3.525-3.6 MHz), General/Extra (voice)
  • Propagation: Nighttime, 500-2000 miles typical
  • Uses: Regional communication, nets, DX at night
  • Power: 1500W PEP max
  • Characteristics: Excellent nighttime band, atmospheric noise

40 meters (7.0-7.3 MHz):

  • Privileges: Technician (CW, 7.025-7.125 MHz), General/Extra (voice)
  • Propagation: Day and night, 500-3000 miles
  • Uses: DX, regional, emergency communications
  • Power: 1500W PEP max
  • Characteristics: Most reliable HF band, 24-hour propagation

30 meters (10.1-10.15 MHz):

  • Privileges: General/Extra only
  • Modes: CW and digital only (no voice)
  • Power: 200W PEP max (lower limit)
  • Propagation: Daytime, worldwide
  • Characteristics: Narrow band, shared with other services, DX popular

20 meters (14.0-14.35 MHz):

  • Privileges: General/Extra (voice)
  • Propagation: Daytime worldwide DX, best overall DX band
  • Uses: International communication, contesting, DX chasing
  • Power: 1500W PEP max
  • Characteristics: Most popular HF band, excellent for beginners

17 meters (18.068-18.168 MHz):

  • Privileges: General/Extra only
  • Propagation: Daytime DX
  • Power: 1500W PEP max
  • Characteristics: Narrow band, less crowded, good DX

15 meters (21.0-21.45 MHz):

  • Privileges: Technician (CW/data, 21.025-21.2 MHz), General/Extra (voice)
  • Propagation: Daytime DX during solar maximum, dead during minimum
  • Power: 1500W PEP max
  • Characteristics: Solar cycle dependent, excellent when open

12 meters (24.89-24.99 MHz):

  • Privileges: General/Extra only
  • Propagation: Similar to 15m, solar dependent
  • Power: 1500W PEP max
  • Characteristics: Narrow band, less crowded

10 meters (28.0-29.7 MHz):

  • Privileges: Technician (28.0-28.5 MHz all modes), General/Extra (entire band)
  • Propagation: Sporadic E, F2 layer during solar max, occasional long-distance
  • Uses: DX, FM repeaters, SSB, AM, CW, digital
  • Power: 1500W PEP max (200W on 28.0-28.3 MHz)
  • Characteristics: Most privileges for Technicians, fun band

6 meters (50-54 MHz):

  • Privileges: Technician and above (all modes)
  • Propagation: Sporadic E (spring/summer), tropospheric, meteor scatter
  • Uses: “Magic band,” DX during openings, local FM
  • Power: 1500W PEP max
  • Characteristics: VHF but propagates like HF during openings

VHF/UHF Bands – Local and Satellite:

2 meters (144-148 MHz):

  • Privileges: Technician and above (all modes)
  • Propagation: Line of sight, tropospheric, occasional sporadic E
  • Uses: FM repeaters, simplex, satellites, SSB weak-signal work, digital
  • Power: 1500W PEP max
  • Characteristics: Most active VHF band, repeater networks

1.25 meters (222-225 MHz):

  • Privileges: Technician and above
  • Propagation: Line of sight
  • Uses: FM, weak signal, data
  • Power: 1500W PEP max
  • Characteristics: Less popular than 2m/70cm, good for experimentation

70 centimeters (420-450 MHz):

  • Privileges: Technician and above (all modes)
  • Propagation: Line of sight
  • Uses: FM repeaters, satellites, digital voice (DMR, D-Star, Fusion), television (ATV)
  • Power: 1500W PEP max
  • Characteristics: Second most popular VHF/UHF band, penetrates buildings well

33 centimeters (902-928 MHz):

  • Privileges: Technician and above
  • Propagation: Line of sight
  • Power: 1500W PEP max
  • Characteristics: Shared with ISM devices, less activity

23 centimeters (1240-1300 MHz):

  • Privileges: Technician and above
  • Uses: Amateur television (ATV), data, weak signal, satellites
  • Power: 1500W PEP max
  • Characteristics: Microwave experimentation, high-speed data

Higher microwave bands:

  • 2.3 GHz, 3.4 GHz, 5.6 GHz, 10 GHz, 24 GHz, 47 GHz, etc.
  • Propagation: Line of sight only
  • Uses: Experimentation, contests, microwave DX
  • Very limited activity except specialized operators

Amateur Radio Operating Rules

Station identification:

  • Must ID with callsign at:
    • End of transmission
    • Every 10 minutes during extended communications
    • Beginning not required (but courteous)
  • CW: At least 20 WPM speed
  • Voice: English language
  • Digital: Automatically or manually

Power limits:

  • General: 1500W PEP maximum
  • Exceptions:
    • 30m band: 200W PEP max
    • 60m band: 100W ERP max
    • Certain microwave bands: Lower limits
  • Minimum necessary power rule: Use lowest power needed for communication

Prohibited transmissions:

  • Music (except incidental background)
  • Broadcasting (one-way transmission for public)
  • Business communications (with narrow exceptions)
  • Compensation for operating (except employment as ham radio instructor, emergency comm, etc.)
  • Encryption (except control links, space stations, limited exceptions)
  • Obscenity, indecency, profanity
  • False signals, unidentified transmissions
  • Causing intentional interference

Third-party traffic:

  • Can pass messages for unlicensed individuals
  • Restrictions for international communications (check third-party agreements)
  • Control operator must be present
  • Cannot relay business messages

Emergency communications:

  • Priority during emergencies
  • Can use any frequency if necessary for safety
  • Can exceed power limits if needed
  • Can operate outside license privileges in emergencies
  • Amateur Radio Emergency Service (ARES), Radio Amateur Civil Emergency Service (RACES)

Repeater operation:

  • Open repeaters available on 2m, 70cm, other bands
  • Courtesy: Pause between transmissions for others to join
  • ID as required (control operator IDs for repeater)
  • Closed repeaters require permission
  • Tone access (CTCSS/DCS) common

Digital modes:

  • Automatically controlled stations allowed
  • Must ID automatically in human-readable format
  • APRS (Automatic Packet Reporting System) popular
  • FT8, PSK31, RTTY, and many others
  • Bandwidth limits vary by band

Multi-Use Radio Service (MURS) – Part 95J

MURS provides license-free VHF operation for personal and business use.

Frequency allocation:

  • 5 channels in VHF business band:
    • 151.820 MHz (Blue Dot, 11.25 kHz narrow bandwidth)
    • 151.880 MHz (Green Dot, 11.25 kHz)
    • 151.940 MHz (Red Dot, 11.25 kHz)
    • 154.570 MHz (11.25 kHz)
    • 154.600 MHz (20 kHz wider bandwidth)
  • VHF propagation: Better than UHF, penetrates foliage well
  • Shared with other grandfathered business users

Power and antenna limits:

  • Power: 2 watts maximum
  • Antennas: External antennas allowed (up to 20 feet above structure or tree)
  • Removable antennas permitted
  • Directional antennas allowed
  • Better range than FRS due to VHF propagation and antenna options

Equipment requirements:

  • Must use FCC-certified MURS radios
  • Homebrew radios not permitted
  • Cannot modify certified equipment
  • Limited radio selection (less popular than FRS/GMRS)

Operational rules:

  • No license required
  • Personal or business use allowed
  • Repeaters prohibited
  • Data transmissions allowed (telemetry, remote control)
  • Station ID not required for voice, required for data
  • Cannot cause harmful interference

Uses:

  • Retail store communications
  • Farm and ranch operations
  • Outdoor recreation
  • Property security
  • Better range than FRS in rural areas

MURS vs. FRS/GMRS:

  • Advantages: VHF propagation, external antennas, business use clear
  • Disadvantages: Limited radio selection, less popular, fewer users

Business Radio Service – Part 90 (LMR)

Land Mobile Radio (LMR)

Commercial and business entities can obtain licensed frequencies for internal communications.

Licensing:

  • Requires FCC license (not individual, but for business/organization)
  • Application through frequency coordinator
  • Must demonstrate legitimate business need
  • No examination required (organizational license)
  • Licenses typically 10 years

Frequency bands:

  • VHF Low (30-50 MHz): Long-range, foliage penetration
  • VHF High (150-174 MHz): Most common business band, good range
  • UHF (450-512 MHz): Building penetration, shorter range than VHF
  • 800/900 MHz: Trunked systems, public safety, commercial

Power limits:

  • Vary by frequency and application
  • Typically: 5-50 watts mobile, 100+ watts base stations
  • Determined by coordination and FCC rules

Equipment requirements:

  • Must use FCC type-accepted radios for Part 90
  • Cannot use consumer FRS/GMRS radios (different Part)
  • Cannot use amateur radios (different service)
  • Professional-grade radios: Motorola, Kenwood, Icom, Hytera

Operational rules:

  • Station ID required (callsign or name)
  • Licensee responsible for all transmissions
  • Employees can operate under organizational license
  • Encryption allowed
  • Repeater systems common

Applications:

  • Construction companies
  • Security services
  • Delivery and logistics
  • Manufacturing facilities
  • Hotels and resorts
  • Schools and universities
  • Municipalities (non-public safety)

Coordination:

  • Frequency coordinators assign frequencies
  • Prevent interference between licensees
  • Different coordinators for different industries
  • Process ensures efficient spectrum use

Public Safety Radio

Frequency allocations:

  • VHF (150-174 MHz): Police, fire, emergency services
  • UHF (450-512 MHz): Some public safety agencies
  • 700 MHz (763-775/793-805 MHz): Public safety broadband, FirstNet
  • 800 MHz (806-824/851-869 MHz): Trunked public safety systems

Licensing:

  • Government entities only
  • Municipal, county, state, federal agencies
  • Coordinated through regional frequency coordinators
  • Strict eligibility requirements

P25 Digital Standard:

  • Project 25 (P25) digital voice standard
  • Interoperability between agencies
  • Encryption capability
  • Modern public safety systems

Prohibitions:

  • Listening to encrypted communications: Legal (can’t decode without keys)
  • Unauthorized transmission on public safety frequencies: Illegal, severe penalties
  • False distress calls: Federal crime
  • Interfering with emergency communications: Criminal offense

Aviation and Maritime Radio

Aviation Frequencies – Part 87

VHF Aviation Band (108-137 MHz):

  • 118-137 MHz: Voice communications (AM mode)
  • 108-117.95 MHz: Navigation (VOR, ILS)
  • 121.5 MHz: Emergency frequency (monitored by all aircraft)
  • 122.75 MHz: Air-to-air (private aircraft)
  • 123.45 MHz: Unofficial air-to-air (not legal but common)

Licensing:

  • Aircraft station license for aircraft
  • Pilot license (from FAA, not FCC) to operate
  • No separate FCC radio operator license for domestic ops
  • International flights: Restricted Radiotelephone Operator Permit

Operational rules:

  • Plain language (no codes except standard aviation terminology)
  • Callsign: Aircraft tail number (N-number)
  • Follow ATC instructions
  • Monitor 121.5 MHz for emergencies

Prohibitions:

  • Unauthorized transmissions on aviation frequencies: Extremely serious, endangers lives
  • False distress calls: Federal crime
  • Interfering with ATC: Criminal offense, immediate investigation
  • Listening: Legal (anyone can receive)

Maritime Radio – Part 80

Frequency allocations:

  • VHF Marine (156-162 MHz): Voice communications, 25 kHz channels
    • Channel 16 (156.8 MHz): Distress, safety, calling (monitored by Coast Guard)
    • Channel 9 (156.45 MHz): Calling for recreational boats
    • Channel 13 (156.65 MHz): Navigation safety (bridges, locks, ports)
    • Channel 6 (156.3 MHz): Intership safety
  • MF/HF Maritime (2-27 MHz): Long-distance vessel communications
  • 406 MHz: Emergency Position Indicating Radio Beacon (EPIRB)
  • 121.5 MHz: Backup emergency (being phased out)

Licensing:

  • Vessel license: Required for vessels traveling internationally, certain commercial vessels
  • Operator license: Required for commercial operators, international travel
  • Recreational: No license required for domestic VHF marine radio use
  • MMSI (Maritime Mobile Service Identity): Unique 9-digit ID for DSC (Digital Selective Calling)

VHF Marine Radio (Recreational):

  • No license required (domestic use)
  • Must use type-accepted marine VHF radio
  • Power: 25 watts for shore, 5 watts for handheld
  • Transmit only when necessary (keep channels clear)
  • Monitor Channel 16 for emergencies

Operational rules:

  • Channel 16: Distress and calling only, switch to working channel after contact
  • Station ID: Vessel name + callsign (if licensed) or just vessel name
  • Plain language (except standard maritime terminology)
  • No profanity or unnecessary communications

Prohibitions:

  • False distress calls: Federal crime, severe penalties, Coast Guard takes very seriously
  • Using marine VHF for non-maritime purposes (not a phone)
  • Excessive calling or transmitting on Channel 16
  • Encryption prohibited on VHF marine
  • Listening: Legal

Emergency procedures:

  • Mayday: Distress (life-threatening)
  • Pan-Pan: Urgency (safety concern, not immediate danger)
  • SĂ©curitĂ©: Safety message (navigation warnings)

Prohibited Frequencies and Actions

Frequencies You Cannot Transmit On

Government and Military Frequencies:

  • 225-400 MHz: Military aircraft (UHF military air)
  • Numerous HF military frequencies
  • Government exclusive bands throughout spectrum
  • Penalty: Severe, especially if interfering with military operations

Public Safety (non-licensed individuals):

  • Police, fire, EMS frequencies
  • Even licensed amateurs cannot transmit on public safety frequencies outside emergencies
  • Penalty: Criminal charges, FCC fines, jail time possible

Cellular and PCS:

  • 824-894 MHz: Cellular
  • 1850-1990 MHz: PCS (Personal Communications Service)
  • Licensed to carriers (Verizon, AT&T, T-Mobile, etc.)
  • Cell phone jammers: Illegal per se, no exceptions
  • Penalty: $10,000+ per violation, equipment forfeiture, criminal charges

Broadcast bands (transmit without license):

  • AM broadcast (530-1700 kHz): Requires broadcast license
  • FM broadcast (88-108 MHz): Requires broadcast license
  • TV channels: Requires broadcast license
  • Low-power FM (LPFM): Still requires FCC license
  • Part 15 transmitters: Allowed with extreme power limits (range typically <200 feet), but cannot cause interference
  • Penalty: $10,000+ per day of operation, equipment forfeiture

Satellite frequencies:

  • Uplinks to satellites (various bands)
  • GPS L1/L2/L5 frequencies (jamming GPS illegal)
  • Satellite phone uplinks
  • Penalty: Severe, especially GPS jamming (endangers aircraft, maritime, military)

Illegal Devices and Activities

Prohibited devices:

  • Cell phone jammers: Illegal to market, sell, or operate
  • GPS jammers: Illegal, endangers public safety
  • CB amplifiers: Over 4W output illegal
  • Pirate radio transmitters: Unlicensed broadcast stations
  • Radar jammers: Illegal (laser jammers legal in some states, not radar)

Prohibited activities:

  • Transmitting without authorization
  • Operating outside license privileges
  • Using non-certified equipment on services requiring certification
  • Causing intentional interference
  • False distress signals
  • Transmitting obscenity
  • Using encryption on services prohibiting it
  • Operating with excessive power
  • Helping others operate illegally

Enforcement:

  • FCC Enforcement Bureau
  • Fines: $10,000-$100,000+ depending on violation
  • Criminal penalties for willful/repeated violations
  • Equipment forfeiture (FCC can seize equipment)
  • Imprisonment (rare, but for serious violations)

Getting Started Legally

For Casual Users (No License)

FRS radios:

  • Purchase FRS radios (Walmart, Amazon, outdoor stores)
  • $20-60 per pair
  • Immediate use, no paperwork
  • Best for: Family outings, hiking, around property

WiFi and Bluetooth:

  • Consumer equipment automatically compliant
  • Purchase certified devices (nearly all are)
  • No special knowledge needed

CB radio:

  • Purchase CB radio ($50-200)
  • Install and operate (no license)
  • Observe power limits (4W AM, 12W SSB)
  • Best for: Vehicle communication, highway travel, emergency backup

For Short-Range Business Use

MURS:

  • Purchase MURS radios (~$50-150)
  • External antennas for better range
  • No license required
  • Best for: Retail, farms, warehouses

GMRS:

  • Apply for license: FCC ULS (uls.fcc.gov)
  • Fee: $35 for 10 years
  • No exam required
  • Purchase GMRS radios ($50-300)
  • Best for: Family, extended range, repeater access

For Serious Radio Hobbyists

Amateur radio:

  1. Study for Technician exam:
    • Study guides: ARRL Technician Manual, HamStudy.org (free), HamTestOnline ($25)
    • 2-4 weeks of casual study typically sufficient
    • Question pool public (all questions published)
  2. Find exam session:
    • ARRL.org/find-an-amateur-radio-license-exam-session
    • Many held monthly in most areas
    • Some remote/online exams available
  3. Take exam:
    • 35 questions, multiple choice
    • Pass: 26 correct (74%)
    • Fee: ~$15
    • Results to FCC within days
  4. Receive callsign:
    • FCC issues callsign automatically
    • Appears in ULS database
    • Usually 5-10 days after passing
  5. Purchase radio and operate:
    • Handheld VHF/UHF: $25-500 (Baofeng, Yaesu, Icom, Kenwood)
    • Mobile: $150-600
    • HF base station: $500-3000+
    • Join local ham radio club for mentoring

Benefits of amateur radio:

  • Most frequency access of any unlicensed service
  • Worldwide communication potential
  • Emergency communication capabilities
  • Experimentation and learning
  • Active community
  • Public service opportunities

For Business Communications

Business radio (Part 90):

  1. Identify need and expected users
  2. Contact frequency coordinator for your industry
  3. Apply for frequencies through coordinator
  4. FCC processes application (30-90 days typical)
  5. Purchase type-accepted business radios
  6. Implement and train users

Cost considerations:

  • Licensing: $0-500 depending on coordinator
  • Equipment: $200-600 per radio
  • Repeater system: $5,000-50,000+
  • Ongoing: License renewal, maintenance

Compliance and Enforcement

FCC Enforcement Process

Complaint-driven:

  • Most enforcement begins with complaints
  • Interference reports from licensed users
  • Neighbor complaints
  • Reports from monitoring stations

Investigation:

  • FCC field agents investigate
  • Direction finding equipment locates sources
  • Can request to inspect station (with warrant if refused)
  • Measurements and documentation

Notice of Violation:

  • First response often warning/notice
  • Describes violation and required corrective action
  • Deadline for response
  • Opportunity to explain or dispute

Forfeiture (fines):

  • Monetary penalties for violations
  • Base amounts in FCC schedule
  • Aggravating factors increase fines:
    • Repeated violations
    • Intentional interference
    • Operating after warning
    • Lack of cooperation
  • Mitigating factors may reduce fines

Equipment seizure:

  • FCC can seize equipment involved in violations
  • Typically for serious or repeated violations
  • Equipment forfeiture proceedings

Criminal prosecution:

  • Referred to Department of Justice for serious violations
  • Typically: Intentional interference, false distress, repeated operation after warnings
  • Penalties: Fines + imprisonment possible

Avoiding Violations

Before transmitting:

  1. Verify you’re authorized for the frequency
  2. Check equipment is legal for the service
  3. Understand power limits
  4. Know operational rules
  5. Have proper licensing (if required)

Equipment:

  • Purchase from reputable dealers
  • Verify FCC ID on devices requiring certification
  • Don’t modify transmitters
  • Keep equipment in good repair

Operations:

  • Identify your station as required
  • Don’t cause interference
  • Use minimum necessary power
  • Follow band plans and conventions
  • Cease transmitting if causing interference

If problems arise:

  • Respond promptly to FCC inquiries
  • Cooperate with investigations
  • Correct violations immediately
  • Document corrective actions
  • Seek legal advice if facing significant penalties

Conclusion

Legally transmitting radio signals in the United States requires understanding FCC frequency allocations, power limits, and licensing requirements specific to your intended use. For personal communications without examination, Citizens Band radio (26.965-27.405 MHz, 4W AM max) requires no license but prohibits amplifiers, while Family Radio Service (462/467 MHz, 2W max, 22 channels) offers license-free UHF operation with fixed-antenna handheld radios available at retail stores. GMRS provides higher power (50W) and repeater access for $35/10-year license requiring no exam—apply online at the FCC Universal Licensing System (uls.fcc.gov) and receive a callsign covering your entire family within 7-14 days.

Amateur radio (ham radio) provides the most extensive legal frequency access for individuals, spanning 1.8 MHz to 275 GHz across multiple allocated bands, but requires passing FCC examinations. The entry-level Technician license ($15 exam fee, no recurring costs) grants all privileges above 30 MHz including repeater access on 2-meter (144-148 MHz) and 70-centimeter (420-450 MHz) bands, limited HF access, and 1500W maximum power for most bands—study free at HamStudy.org for 2-4 weeks, find exam sessions at ARRL.org, and receive your callsign automatically 5-10 days after passing. General and Extra class licenses require additional exams but unlock full HF band access for worldwide communication via ionospheric propagation.

WiFi and Bluetooth operate legally under Part 15 unlicensed rules on 2.4 GHz and 5 GHz ISM bands without individual licensing, provided you use FCC-certified consumer equipment unmodified. These devices must accept all interference and cannot cause harmful interference—increasing WiFi router power beyond certified limits or using non-certified equipment constitutes illegal operation. Similarly, all IoT devices, garage door openers, wireless doorbells, and short-range communications use type-accepted equipment under Part 15, requiring no licenses but prohibiting modifications.

Transmitting on frequencies outside your authorization carries serious consequences: $10,000+ fines per violation, equipment forfeiture, and criminal prosecution for willful infractions. Cell phone jammers, GPS jammers, pirate FM broadcasters, and unauthorized transmissions on public safety, military, aviation, or maritime frequencies face particularly severe enforcement including potential imprisonment. Always verify frequency authorization, use certified equipment, observe power limits, and immediately cease transmission if causing interference—when in doubt, obtain proper licensing through amateur radio (most flexible) or GMRS (family communications) rather than risk illegal operation.

© C3DNA