Washington Laboratories (301) 417-0220 web: Lindbergh Dr. Gaithersburg, MD 20879 2014/6/61 Wireless Product Testing William H. Graff, AmericanTCB.

Wireless Product TestingWilliam H. Graff, AmericanTCB

FCC 47 CFR Regulations

Part 2 General Requirements

Part 15B Unintentional Radiators

Part 15C/D/E/F Intentional Radiators

Part 18 ISM Devices

All Other Rule Parts: Licensed Devices

Part 2 – General Requirements

Basic reference section on “how to” create an FCC filing.

Oldest part of the FCC rules.

All necessary requirements begin with Part 2

FCC Rules predate industry standards

Equipment Authorizations

There are three basic types of equipment authorizations:o Verificationo Declaration of Conformityo Certification

VerificationSimplest of all Equipment Authorizations

No submission to FCC

Data is held by Applicant/Manufacturer

Proof that equipment was tested and found to be compliant at a given point in time

Examples: Broadcast Receivers, TVs, Class A Digital Devices, BPL (consumer)

Declaration of ConformityMore complex than Verification

No submission to FCC

Must be done at an Accredited Laboratory

Country where testing takes place must have signed MRA with USA

“Responsible Party” must reside on US soil

Examples: Class B computers and peripherals, microwave ovens for consumers,

CertificationUsed for all equipment authorizations involving

Licensed or Unlicensed transmitters. Can be used optionally for Class B

computers/peripherals, comsumer microwave ovens, etc.

Submission to FCC database is mandatoryIs more than just an “engineering report”. It is a

legal document.

Requires a detailed list of “Exhibits” (See 2.1033)Examples: All Licensed transmitters, all Unlicensed

Part 15 “Intentional Radiators”, radar detectors, scanning receivers

Changes to Certified Equipment

Known as “Permissive Change”o Changes which have no effect on RF

emissions or performance [Class 1]o Changes which affect emissions or

performance but still within the limits [Class 2]

o Changes to RF software [Class 3] – This is only applicable to devices which qualify as Software Defined Radio (SDR)

Class I Permissive Change

Changes which have no effect on the emission characteristics of a device

No submission to FCC

Test Report is created, but held by Applicant / Manufacturer

Examples: Color

Class II Permissive Change

Changes which may potentially affect the emissions of a device

Submission required to FCC

Examples: New PCB layout, new antenna, new “host” (re: modular approval)

Forbidden Class II Changes(requires new ID / new submission)

Changes to frequency determining circuit

Changes in RF power

Changes from one RF category to another

Changes to modulation or timing

Changes in basic functionality (i.e. dual band to single band)

Permit-But-Ask ProcedureNew! as of November, 2006

FCC has initiated a new procedure for “troublesome” filings and new technology. Prior to any request for Certification, a TCB must request guidance from FCC on specific items to look for before granting Certification.

Specifically aimed (so far) at 15.239 personal FM transmitters, WiMax devices and 3.5/4G cellphones.

See FCC Memo to TCBs.

Licensed Transmitter Approvals

Licensed Radio Services General Testing Requirements

FCC Part 2.1046 through 2.1057 Cover tests for all licensed devices.

The basics rationale of all FCC tests originate within this section. This is the oldest of the FCC rules

Built for the “narrowband world”, but still adaptable to broadband radio concepts

Licensed Radio Services Test Parameters

2.1046 - Power Output

2.1047 - Modulation Characteristics

2.1049 - Occupied Bandwidth

2.1051 - Antenna Terminal Spurious Emissions

2.1053 - Radiated Spurious Emissions

2.1055 - Frequency Stability for Temperature and Voltage Variations

Licensed Radio Services Test Parameters

Remember that the purpose of performing the measurements required and submitting interpretations is to establish compliance with the technical requirement contained in the Radio Service Rules. These rules are “pre-standards”. In other words they evolved before there were generally accepted measurement standards and practices.

Basic Test Parameters

Power Output: 2.1046o Traditionally thought of as a “caloric”

measurement. Use of common CW power meters were common. Great deal of measurement certainty.

o Part 15 began the usage of “peak reading” power meters. Most unlicensed transmitter sections still require the concept of “peak power” unless specifically stated otherwise

Basic Test Parameters

Modulation Characteristics 2.1047o For analog radio transmissions (AM, FM, SSB)

understanding basic parameters such as audio response and audio low pass filter were necessary to determine compliance. Testing usually required

o For today’s “constant envelope” digital modulation systems this is basically unnecessary, but still must be described. Testing usually not required.

Basic Test Parameters

Occupied Bandwidth 2.1049o Occupied Bandwidth is defined as that portion of

the spectrum where 99% of the emitted energy exists. The results are used to compare modulated spectrum with emissions masks.

o Although not explicitly specified, all Certification reports including Part 15 must have an occupied bandwidth plot

o Plot should be presented for each type of modulation

Basic Test Parameters

Antenna Terminal Spurious Emissions 2.1051

(Also known as Antenna Conducted Emissions)

o View levels of conducted harmonics applied to the antenna.

o An extension of the occupied bandwidth test. Show spurious emissions to 10th harmonic.

o Unless specified elsewhere, RBW should be equal or greater than Tx emission bandwidth

0

Basic Test Parameters

Field Strength of Spurious Emissions 2.1053o Test includes emissions radiated from the cabinet,

chassis, and associated wiring. The specification is the same emission mask under the Radio Service rules extended to the highest frequency specified in 2.1057. Traditionally a “terminated transmitter” is tested without antenna.

o For Licensed equipment, the substitution method described in TIA/EIA 603 is the required test procedure.

o For Part 15 emissions testing, direct measurement of field strength is accepted. Device must be tested with it’s antenna in place.

Basic Test Parameters

Frequency Stability 2.1055o Done over temperature [-30 C to +50 C] and

operating voltage [+/- 15%] specifications.o Battery operated devices should also include B.E.P

[Battery End Point]o Usually defined in ppm but other units such as Hz,

% are accepted as defined in specific rule section.o In most cases, frequency stability is not required for

Part 15

Certification Checklist – Check for Accuracy

Applicant name, address, contact info, email address. There must be agreement with the supplied contact information and the Grantee contact information at FCC website.

Agent Authorization LetterConfidentiality Request LetterFCC ID:Equipment Class – if not known ask!Rule Part(s)Frequency RangePower OutputRequested Emission Designator

Certification Checklist

Associated Application (Composite Request)Confidentiality Request (See separate details for STC)Details to be included with confidentiality.

o Block Diagramo Schematicso Operational Descriptiono Parts/Tune Up

Statement / letter supplied for special requirements or interagency coordination (if required).

Licensed and Unlicensed Transmitter Exhibits

Certification Requirements for exhibits, labeling, etc, differ somewhat from the Licensed world.

Compare 2.1033(c) [Licensed Tx] with 2.1033(b) [Part 15] for Exhibit list

Compare 15.19(a)(3) with 15.19(a)(1) for label language. Devices which are Licensed transmitters only with no accociated receiver can omit all 15.19 langrage

All Part 15 devices must address 15.21 and 15.105 for manual

RF Exposure language is additional

Unlicensed Part 15 Transmitter Approvals

Part 15 Rule Organization

o All general rules including measurement procedures, label requirements, etc. are located in 15.xx (Subpart A)

o All Unintentional Radiators are located in Part 15.1xx of the Rules (Subpart B)

o All Intentional Radiators are located in the 15.2xx sections of the Rules (Subpart C), 15D (unlicensed PCS), 15E (UNII) and 15F (UWB)

Essential Part 15 Transmitter Requirements

15.203 Antenna Requirements

15.204 External amplifier restrictions

15.205 Restricted Bands

15.207 Conducted Requirements

15.209 Radiated Requirements

15 C Intentional Radiators

Special note: FCC 15.207 & FCC 15.209

Equivalent to 15.107 and 15.209 Class B computer limits.

Unless indicated otherwise, all spurious emissions from Part 15 transmitters should be to these limits.

15.203 Antenna Requirements

An intentional radiator shall be designed to ensure that no antenna other than that furnished by the responsible party shall be used with the device.

15.204 “Power Amp” Restrictions

o Officially referred to as a “Transmission System”o For spread spectrum transmitters usually includes the

bi-directional amplifier, DC injector, and spread spectrum transceiver under one FCC ID:

o Amplifiers designed for use with Spread Spectrum Systems must be approved as part of the system and marketed as part of a complete package. Amplifiers cannot be marketed without pairing to specific transceiver.

o Only approved antennas may be sold with the product. New antenna can be added under the Class II PC process.

15.205 Restricted Bands

Bands are generally US Government and military

The field strength of emissions appearing within these frequency bands shall not exceed the limits shown in §15.209.

Basis for all radiated “band edge” requirements.

Caution: Restricted Bands change over time

AC Conducted Limits 15.207

Except for battery-only powered devices, all Part 15 transmitters must have AC Conducted test. This includes Modular Approvals under DA 00-1407Conducted emissions not required for battery powered devices that make no provisions for attachment to AC power.Follow test procedure in ANSI C63.4Unless otherwise specified, all Intentional Radiators must meet 15.207 limits.

Radiated Emission Limits 15.209

Unless specified elsewhere, all Intentional Radiators must meet 15.209 limits anywhere outside of their allotted frequency band.Test set-up per ANSI C 63.4 limits.Limits identical to FCC Class B. Tighter limits apply at all band edgesWatch for specific rules for the device.Intentional radiators must generally be measuredto the 10th Harmonic

Part 15 C – Intentional Radiators

15.215 Additional Provisions to the General Radiated Emission Limitations

o Prolog to 15.217 to 15.255

15.215(b) Emissions outside “parking space” must meet Class B limits.

15.215(c) Emissions should stay within central 80% of band.

15.215(d) Emissions must take into account sweeping, hopping and other modulation techniques – including OOK

Part 15 C Intentional Radiators§15.217 Operation in the band 160-190 kHz. §15.219 Operation in the band 510-1705 kHz §15.221 Operation in the band 525-1705 kHz. §15.223 Operation in the band 1.705-10 MHz. §15.225 Operation within the band 13.110-14.010 MHz. §15.227 Operation within the band 26.96-27.28 MHz. §15.229 Operation within the band 40.66-40.70 MHz. §15.231 Periodic operation 40.66-40.70 MHz and above 70 MHz. §15.233 Operation within the bands 43.71-44.49 MHz, 46.60-46.98 MHz, 48.75-49.51 MHz and 49.66-

50.0 MHz. §15.235 Operation within the band 49.82-49.90 MHz. §15.237 Operation in the bands 72.0-73.0 MHz, 74.6-74.8 MHz and 75.2-76.0 MHz. §15.239 Operation in the band 88-108 MHz. §15.240 Operation in the band 433.5-434.5 MHz. §15.241 Operation in the band 174-216 MHz. §15.242 Operation in the bands 174-216 MHz and 470-668 MHz. §15.243 Operation in the band 890-940 MHz. §15.245 Operation within the bands 902-928 MHz, 2435-2465 MHz, 5785-5815 MHz, 10500-10550 MHz,

and 24075-24175 MHz. §15.247 Operation within the bands 902-928 MHz, 2400-2483.5 MHz, and 5725-5850 MHz. §15.249 Operation within the bands 902-928 MHz, 2400-2483.5 MHz, 5725-5875 MHZ, and 24.0-24.25

GHz. §15.250 Operation of wideband systems within the band 5925-7250 MHz §15.251 Operation within the bands 2.9-3.26 GHz, 3.267-3.332 GHz, 3.339-3.3458 GHz, and 3.358-3.6

GHz. §15.252 Operation of wideband vehicular radar systems within the bands 16.2-17.7 GHz and 23.12-29.0

GHz. §15.253 Operation within the bands 46.7-46.9 GHz and 76.0-77.0 GHz. §15.255 Operation within the band 57-64 GHz. §15.257 Operation within the band 92-95 GHz.

Part 15 Most Common Sections

15.227 27MHz Toys

15.231 Momentary-On Remote Controls

15.235 49MHz Toys

15.239 88 - 108 MHz Personal FM Transmitters*

15.247 Spread Spectrum Transmitters*

15.407 UNII Devices*

Part 15D - Unlicensed PCS Bands

1910 - 1930 MHz2390 - 2400 MHz

Unique Antenna Connector Required3 dBi Max (1 to 1 Power Reductions vs. antenna gain)OK for TCB approvalRarely used FCC section. But more activity this past year as this section has recently been re-written

Still very complicated.

Part 15E - UNIIUnlicensed National Information Infrastructure

5.15 - 5.25 GHz5.25 - 5.35 GHz5.47 - 5.7255.725 - 5.825 GHz**

802.11a transmittersSpecific power and usage limitations for each bandIndoor use only in the 5.25 - 5.35 GHz band. DFS compliance required – filing to FCC

**Also shared with 15.247

Part 15 F: UWB (Ultra-Wide Band)

Adopted in April of 2002

Does not yet qualify for TCB Approval

No standardized test procedures yet adopted

Devices range from see-through-wall devices, ground radar for construction and safety, to low power communication.

Operates over wide area of band (1 to 3 GHz wide signals)

Spread Spectrum Devices

DTS/DSSS and FHSS(WiFi and Bluetooth)

Spread Spectrum Definitions

Direct Sequence and DTS - use a sequential modulation to spread a narrow signal over a relative broad band.

Example: 802.11b/g

Frequency Hopper - uses an encoded narrow band signal that shifts in a pseudorandmly generated frequency shifts.

Example: Bluetooth

Hybrid – a combination of both Frequency Hopping and Direct Sequence systems

Spread Spectrum Frequencies

o Operate in the Industrial, Scientific, and Medical bands on a secondary basis.

o ISM bands are global and not restricted by ITU regions

o No protection from interferenceo 902 - 928 MHzo 2400 - 2483.5 MHzo 5725 - 5850 MHz

WiFi 802.11b/g channels

FCC rule interpretations do not allow the end user to select the country or region, nor do they allow the end user to download “International” driver channel sets. The only legal channels are Channel 1 (2412MHz) to Channel 11 (2462 MHz)

FCC Rules for Spread Spectrum Transmitters

Power Output 1 Watt Max (except for specific cases)

EIRP 4 Watts Max (except Point to Point)

Antenna Gain: limited to +6 dBi without power reduction from transmitter of 1 dB power for every 1 dB antenna exceeds 6 dBi

Unique antenna connector required (except under professional installation)

Additional FCC Requirements

For systems operating strictly as a Point to Point systems

o in the 2400 - 2483.5 MHz band, the power reduction requirement is 1 dB for every 3 dB the antenna exceeds 6 dBi

o in the 5725 - 5850 MHz band may employ antennas with directional gain greater than 6 dBi without reduction in transmitter output power.

Additional Requirements

o Must Operate on Non-Interference Basis (cannot interfere with others)

o Must accept that interference may affect operation – no legal recourse

o Out of Band requirements including being 20 dBc down in any 100 kHz outside the Band of Operation (In reality, ~75 dBc down from peak in the Restricted Bands is probably necessary)

Spread Spectrum Testing

o Radio testing typically performed in several parts

o Lab bench testing for all conducted testso Listed open field test site or Semi-Anechoic

Chamber required for all radiated tests.

Spread Spectrum Test Software Requirements

o Must be able to turn on/off transmitter, select antenna ports, and go to receive-only mode.

o Must be able to select low , mid, and high channels.o Must be able to run in continuous transmit mode.

This means without any carrier pulsing. If this requirement cannot be met, then additional corrections are required for many tests.

o Must be able to check across all data rates and modulations.

o For Bluetooth, must be able to set to DH1, DH2, DH3

MIMO (802.11n) Considerations

o 802.11n is not a huge compliance issue.o Be sure to measure RF Pout across each

“chain” or output porto Pout on Grant will be sum of all powers.o SAR measurements are still under

development by the Commission. Some guidance is available

Family Antenna Approvals

Allows the use similar antennas without re-testing or filing a Class II Change.

o Example: A 2dBi inverted-f antenna originally approved for use with a specific device. A manufacturer can substitute a 0dBi inverted-f from a different supplier without re-testing as long as conducted TX output power remains the same

o If new antenna of greater gain or different type, then Class II PC must be filed.

Modular Approval - DA00-1407

Must have its own FCC ID number on the module itself. o An ID inside manual is never sufficient.

An additional label is required on the outside of the final host device with wording such as:

o “Contains Inside FCC ID: XXXxxx”

Must meet the Requirements of OET 65 for RF Safety

Full Modular Approvals

By Definition, these transmitters must have own reference oscillator. In addition a separate letter on Applicant letterhead addressing all these items must accompany the filing:

1. RF shielding.2. Buffered data input/output ports 3. Power supply regulation4. Permanent antenna or unique connector5. Testes in “stand alone” condition6. Labeled with own ID number7. Instructions to operator / OEM integrator8. Must meet RF Exposure requirements.

Limited Modular Approval (LMA)

If any of the 8 elements on the preceding slide cannot be met, a limited modular approval may be obtained in some circumstances. LMAs define special circumstances where Certification is valid

Example 1: Wireless mini-PCI 802.11b/g card without voltage regulation

Example 2: Wireless mini-PCI 802.11b/g card with SAR results which may apply to a specific chassis or model notebook PC host.

15.203 Unique Connector Requirement

Standard Connectors now include: o SMA, TNC, BNC are not allowedo MMCX, MCX and reverse SMA,TNC are

possible candidates for in this listo “Integral Antenna” requirements which used

to be part of 15.407 have been eliminated

15.204 Power Amplifier Restrictions

o Must be seen as a complete end-to-end “transmission system”.

o Must include seperately approved transmitter and antenna, in addition to amplifier.

o Amplifiers designed for use with Spread Spectrum Systems must be approved as part of the system and marketed as part of a complete package.

o Additional clarification to 15.204 requirements exist in FCC Knowledgebase.

Spread Spectrum RF Exposure Requirements 15.247 (b)(4) : System shall be operated to ensure that public is not exposed to levels of RF emissions that exceed the recommended FCC Guidelines

References:

o OET 65 Supplement C o TCB July 17, 2002 Exclusion list

General RF Exposure Definitions Fixed or mast mounted on permanent outdoor structures.

Mobile equipment - greater than 20 cm to the body

Portable equipment -20 cm or less to the body.

Note: A device may be subject to multiple categories depending on its use. In this specific case, particular attention must be all possible usage conditions.

Spread Spectrum RF Exposure Requirements

Fixed and Mobile Devices must meet OET-65 MPE RF Safety Requirements (1 mW/cm2 for 2.4 GHz Devices)

Portable devices are subject to SAR evaluation when conducted or EIRP output power is greater than 60/f(GHz) if contact with antenna is possible, or 120mW/f(GHz) if a distance of 2.5cm can be assured.

o Does not apply to 15.407 UNII 802.11a. All RF category Portable 802.11a devices must undergo SAR evaluation regardless of RF Pout

Spread Spectrum Test System Requirements o All reading below 1 GHz in Quasi-Peak.o All readings in both Peak and Average above 1 GHz.o Plots of Band Edge Measurements or Marker Delta

method

Spread Spectrum Testing Transmit Power Peak Measurement - Antenna conducted measurement

Use power meter with peak head detectoro Note: Certain power meters with VBW specifications

less than the 6 dB bandwidth of the fundamental have caused concern and should be avoided

Diode detector/signal generator substitution method with an oscilloscope.

RMS measurement techniques during the period of the data burst allowed.

Spread Spectrum Testing Radiated Transmit Power Peak Measurement.

With highest gain of each antenna family

With lowest gain antenna and EUT at Max Power

Spectrum Analyzer settings:o RBW = 1 MHzo VBW > RBW

Spread Spectrum Testing

Band Edge (Radiated) Low and Highest Frequency of operation

Peak Readings o RBW = 1 MHz VBW > RBW

Average Readings o RBW = 1 MHz VBW = 10Hz

Spread Spectrum Testing Harmonics (Radiated)

o Frequencies : Low, Middle, Highest channels

Spectrum Analyzer settingso Peak mode: RBW = 1 MHz VBW > RBWo Average: RBW = 1 MHz, VBW = 10 Hz.

Average method assumes carrier is at 100% transmit duty cycle. Different settings may need to be employed if duty cycle is less than 100%

Spread Spectrum Class II changes cover:

o Addition of second antennao Modification of RF Exposure reporto Moving from one RF category to another is

discouraged

Limited test suites can be used.o i.e. PCMCIA card with new layout would

require new SAR test plus radiated emissions only. No bench tests required.

Spread Spectrum Submittal Requirements All spurious emission data above 1 GHz taken with average detector, but peak must be provided to show compliance with 15.35(b)

Data and plots (peak & average) for band edge emissions

Harmonics (peak & average) to 10th harmonic

TX power (radiated & conducted)

15.247 Out of Band Emission Requirements

In any 100 kHz bandwidth outside the frequency band in which the spread spectrum intentional radiator is operating, the radio frequency power that is produced by the intentional radiator shall be at least 20 dB below that in the 100 kHz bandwidth within the band that contains the highest level of the desired power, based on either an RF conducted or radiated measurement.

Transmitter Power Output Test

Preferred RF Pout measurement – Peak Power Meter or RMS during period of data burst

When measuring RF Conducted Power with spectrum analyzer - recommended setting of RBW > 6 dB of EUT emission bandwidth VBW > RBW

Band Edge Testing – below 2400 MHz

o Test on Channel 1o For Frequencies between 2390 - 2400 MHz signals

must be 20 dBc down from fundamental.o For 2390 MHz to 2300 - signals must comply with

15.209 levels (Restricted Bands of 15.205)o Must test in all data rates.

Band Edge Testing – above 2483.5 MHz

o Upper restricted band begins at 2483.5 MHz band edge - all signals must be compliant to 15.209 limits

o Difficulties in compliance when 802.11b/g set to channel 11. This consistently is the hardest test.

o Some equipment programmed to special power limits just to comply with restricted band.

o Must test in all data rates

Harmonics \ Spurious \ Restricted Bands Testing

o Required for Each transmitter and Antenna Combination.

o Lowest, Middle, and Highest Frequency checkedo “Worst Case” RF Pout/data rate checkedo Up to 10th Harmonic of Fundamentalo Requires Pre Amp and High Pass Filtero Testing Distance 3 meters

FCC Submittal Information

Test Data: o Max Output Power (at Antenna port and EIRP)o Quasi-Peak < 1 GHzo Both Peak and Average > 1 GHzo Plots of Band Edge Measurements or Marker Delta

method

UNII Devices (802.11a)

UNII Devices Part 15 Subpart E

Unlicensed National Information Infrastructure

Rules adopted in 1997

These devices are part of the TCB Scope

Frequencies of Operationo 5150 - 5250 MHz (Indoor Use Only)o 5250 - 5350 MHz (DFS/TPC Required)o 5470 - 5725 MHz (DFS/TPC Required)o 5725 - 5825 MHz (Shared with 15.247)

UNII Devices Part 15 Subpart E

Transmitter Power Outputo 5150-5250 MHz Band 50 mWo 5250-5350 MHz Band 250 mWo 5470-5725 MHz Band 250 mWo 5725-5825 MHz Band 1 Watt

All RF category Portable UNII devices must have SAR testing

UNII Devices Part 15 Subpart E

All DFS test reports must be approved by FCC

Client only devices which do not have DFS but will change channels in response to commands from an access point are allowed to be approved by TCBs

Client only devices must be tested with DFS capable “golden transmitter”

Client only devices cannot be capable of “ad-hoc” capability

UNII Devices Part 15 Subpart E

Antennas limited to 6 dBi gain without transmitter power reduction.

Low bands may use antennas > 6 dBi, however transmit power and power spectral density must be reduced by gain of antenna that exceed 6 dBi

5.8 GHz band allows use of up to 23 dBi gain antenna for point to point systems without transmitter power reduction.

Contact InformationWilliam H. Graff

President and Director of Engineering

AmericanTCB, Inc.

6731 Whittier Ave.

McLean, VA 22101

mailto: [email protected]

Corporate Phone: (703)847-4700

Corporate FAX: (703)847-6888

Direct Mobile: +886 920399260

SKYPE: whgraff