NEXCOM V3 Radio Draft PD V0.2 - October 27 2020.pdf

NEXCOM V3 Radio October 27, 2020, V 0.2 ii

DEPARTMENT OF TRANSPORTATION

FEDERAL AVIATION ADMINISTRATION

PRODUCT DESCRIPTION (PD)

NEXCOM V3

VERY HIGH FREQUENCY (VHF) RECEIVERS AND TRANSMITTERS

ULTRA HIGH FREQUENCY (UHF) RECEIVERS AND TRANSMITTERS

Technical Operations, ATO

ATC Communications Directorate

DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited.

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Revision Date Action

0.0 10/16/2020 Initial DRAFT issue, non-baselined

0.1 10/22/2020 Changed file name and title page from NEXCOM III to NEXCOM V3, inserted

3.4.2.1.c and updated the related Note 1; updated wording of 3.5.2.2.b

0.2 10/27/2020 Updated Section 2.0, updated table references iv

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1 SCOPE

1.1 Identification

1.2 System Overview

2 APPLICABLE DOCUMENTS

2.1 Government Documents

2.1.1 Specifications

2.1.2 Standards

2.1.3 Other Government Documents

2.2 Non-Government Documents

2.3 Documentation Sources

2.3.1 FAA Documents

2.3.2 Military and Federal Documents

2.3.3 OSHA Documents

2.3.4 FCC Documents

2.3.5 NTIA Documents

2.3.6 IEEE/ANSI Documents

2.3.7 EIA Documents

2.3.8 ETSI Documents

2.3.9 EUROCAE Documents

2.3.10 IEC Documents

2.3.11 IETF Documents

2.3.12 NFPA Documents

3 REQUIREMENTS

3.1 Definitions

3.1.1 “Shall”

3.1.2 “Should”

3.1.3 “Will”

3.2 Radio Requirements

3.2.1 Radio Functions and Software Requirements

3.2.1.1 Modes of Operation

3.2.1.2 Tuning Ranges

3.2.1.3 DSB-AM Modulation Method

3.2.1.4 Firmware and Processor Requirements

3.2.1.5 Radio Service Recovery

3.2.2 Performance Requirements

3.2.2.1 Receiver Requirements

3.2.2.2 Transmitter Requirements

3.2.3 Radio Control, Monitoring, and Reporting

3.2.3.1 Radio Control

3.2.3.2 Radio Control Parameters

3.2.3.3 Radio Query Parameters

3.2.3.4 Radio Monitoring and Reporting

3.2.3.5 Vendor Built-in Test (BIT)

3.2.4 Internet Protocol (IP) Requirements

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3.3 Interfaces

3.3.1 Radio Interfaces

3.3.1.1 Radio Frequency (RF) Connectors

3.3.1.2 Electrical Input Power Connectors

3.3.1.3 Receiver Remote Interface Connector

3.3.1.4 Transmitter Remote Interface Connector

3.3.1.5 Transmitter Local Microphone Connector

3.3.1.6 Receiver Local Headset Connector

3.3.2 Additional Connectors

3.3.2.1 MDT Connector

3.3.2.2 Internet Protocol (IP) Interface Connector

3.3.2.3 Reference Frequency Monitor Connector

3.4 Construction Requirements

3.4.1 Physical Requirements

3.4.1.1 Workmanship

3.4.1.2 Equipment Size

3.4.1.3 Equipment Weight

3.4.1.4 Nameplates

3.4.1.5 Radio Installation/Removal

3.4.1.6 Radio Set-Up

3.4.1.7 Thermal Protection

3.4.1.8 Shock and Vibration Protection

3.4.1.9 Grounding, Bonding, and Shielding

3.4.1.10 Acoustical Noise Criteria Requirement

3.4.1.11 Materials, Processes, and Parts

3.4.1.12 Safety

3.4.1.13 Human Performance/Human Engineering

3.4.1.14 Removable Parts, Mating Connectors, and Interface Cables

3.4.1.15 Test Points

3.4.1.16 Controls

3.4.1.17 Radio Identification (ID) Numbering

3.4.2 Electrical Requirements

3.4.2.1 Input Power Requirements

3.4.2.2 Power Cords

3.4.2.3 Reverse Polarity Protection

3.4.2.4 Circuit Protection

3.4.2.5 Loss of Input Voltage

3.4.3 Environmental Conditions

3.4.3.1 Thermal Design Requirements

3.4.3.2 Operating Conditions

3.4.3.3 Non-Operating Conditions

3.4.4 Electromagnetic Compatibility Requirements

3.4.5 FCC Equipment Certification

3.5 Quality Factors

3.5.1 Reliability

3.5.1.1 Mean Time Between Failures

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3.5.2 Maintainability

3.5.2.1 Mean Time To Repair

3.5.2.2 Periodic Maintenance

3.5.3 Service Life

4 QUALITY ASSURANCE PROVISIONS

4.1 Testing Conditions

4.1.1 Receiver Test Signals and Conditions

4.1.1.1 Test Signal Sources

4.1.1.2 Rated Desired Signal

4.1.1.3 Standard Desired Signal

4.1.1.4 Standard Undesired Signal

4.1.1.5 Squelch Condition For Test

4.1.1.6 Rated Audio Output Power

4.1.1.7 Standard Audio Output Power

4.1.1.8 Rated Audio Band

4.1.1.9 Audio AGC Condition For Test

4.1.2 Transmitter Test Signals and Conditions

4.1.2.1 Coaxial Termination

4.1.2.2 Signal Sources

4.1.2.3 Standard Test Signal

4.1.2.4 Rated Output Power

4.1.3 Test Frequencies

4.1.4 Normal Load

4.2 Tests

4.2.1 Electromagnetic Compatibility Tests

4.3 Verification Methods and Verification Requirements Traceability Matrix (VRTM)

4.4 Reliability Modeling and Prediction Data

5 PREPARATION FOR DELIVERY

6 NOTES

6.1 Notes on Information Items

6.2 Applicable Definitions

6.2.1 Very High Frequency (VHF)

6.2.2 Ultra High Frequency (UHF)

6.2.3 Mean Time Between Failures (MTBF)

6.2.4 Mean Time To Repair (MTTR)

6.2.5 Duty Cycle

6.2.6 Modular Construction

6.2.7 Line Replaceable Unit (LRU)

6.2.8 Adjacent Channel Emissions

6.2.9 Transmitter Spectral Mask

6.2.10 Antenna Transfer Relay (ATR) Function

6.2.11 Initialization

6.2.12 Factory Reset

6.2.13 Warm Reset

6.2.14 Service Restoral

6.2.15 Non-Volatile Memory

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6.2.16 Equipment Failure

6.2.17 Configuration of Chaining Multiple Radios to a Common Antenna Using the ATR

6.2.18 Equipment Size

6.2.19 Local(ly)

6.2.20 Remote(ly)

6.2.21 Push-to-Talk (PTT)

6.2.22 Maintenance Data Terminal (MDT)

6.2.23 MDT Software (MDTS)

6.2.24 Interface

6.2.25 Degraded Performance

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Table 3-1 Transmitter Nominal Radio Frequency Output Power Configurations

Table 3-2 Tuning Ranges

Table 3-3 Receiver Selectivity Profile

Table 3-4 Receiver Spurious Frequency Rejection Undesired Signal

Table 3-5 Receiver Intermodulation Undesired Signals

Table 3-6 Receiver Audio Frequency Response Audio Bands

Table 3-7 Receiver Collocation Cases

Table 3-8 Receiver Rejection of Signals Outside the Band Undesired Signal Cases

Table 3-9 Receiver Automatic Gain Control (AGC) Stabilization Undesired Signal

Table 3-10 Transmitter Audio Input Signal Ranges

Table 3-11 Transmitter RF Output Power Ranges

Table 3-12 Transmitter Back Intermodulation Cases

Table 3-13 Transmitter Adjacent Channel Power Mask

Table 3-14 Typical MDT Hardware/Software

Table 3-15 Minimum Required Control Parameter Set

Table 3-16 Minimum Desired Control Parameter Set

Table 3-17 Minimum Required Query Parameter Set

Table 3-20 Radio Functions and Labeling

Table 3-21 Maximum Current Limits

Table 3-22 Operating Conditions

Table 3-23 Non-Operating Conditions

Table 4-1 Rated Audio Bands

Table 4-2 Test Channels

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Figure 3.1 Illustration of Normal, Alert, and Alarm Range for a Parameter

Figure 6.1 Transmitter Spectral Mask

Figure 6.2 Conceptual Illustration of Internal Filter/Antenna Transfer Relay Configuration

Figure 6.3 Conceptual Illustration of Transceiver Configuration

Figure 6.4 Conceptual Illustration of Transmitter Main/Standby Configuration

Figure 6.5 Rack Unit Definitions

LLIISSTT OOFF AAPPPPEENNDDIICCEESS

Appendix A List of Acronyms ............................................................................................................... A-1

Appendix B Verification Requirements Tracability Matrix (VRTM) ................................................... B-1

Appendix C FAA ED-137 Radio Maintenance Data Terminal Software (MDTS) Requirements…….C-1

1 SCOPE

1.1 Identification

This document contains the Product Description (PD) for the NEXt generation air/ground (A/G)

COMmunications (NEXCOM) System Ultra High Frequency (UHF) and Very High Frequency

(VHF) radios. This PD describes the features and performance requirements necessary for the radio equipment to satisfy the NEXCOM Version 3 Radio Program. All requirements in this PD are common to both the UHF and VHF radios unless the requirement specifically addresses a particular radio.

1.2 System Overview

The Federal Aviation Administration (FAA) requires A/G voice communications links to provide Air Traffic Control (ATC) services to all classes of National Airspace System (NAS) users. These links support all phases of flight including en route, terminal approach control, flight service and terminal space-based ground movements; departures and arrivals. The

UHF/VHF radios are used to ensure aircraft separation, transmit instructions and clearances, permit hand-offs, provide weather services and pilot reports (PIREPs), and communicate with

Automated Flight Service Stations (AFSSs). Civilian aircraft, including air carrier and general aviation, are served in the VHF band while Department of Defense (DOD) aircraft are served in the UHF band.

The NEXCOM Version 3 Radio Program will replace current UHF/VHF ground-based analog radios at Remote Center Air/Ground (RCAG) facilities supporting En Route Communications.

Version 3 radios will operate using the current 25 kHz channel-spacing assignment in their respective radio frequency (RF) bands. Each radio band will support signal-in-space communications using a double sideband-amplitude modulation (DSB-AM) waveform. The

VHF radios will also have frequency tuning capabilities to operate on 8.33 kHz channel-spacing assignments in accordance with International Civil Aviation Organization (ICAO) defined standards.

Version 3 radios will be physically compatible with today’s existing NAS equipment, be equipped with a legacy analog audio interface(s) as well as an ED-137C compliant Internet

Protocol (IP)-based audio interface(s) supporting future NAS gateway subsystems and components.

2 APPLICABLE DOCUMENTS

The following documents form a part of the NEXCOM Version 3 Radio PD. Each document is applicable in full unless specified herein. The version of each identified document that is in effect at the time of vendor proposal receipt for the FAA is applicable, unless explicitly noted. In case of conflict between the documents referenced and the contents of this PD, the contents of this

PD shall take precedence.

2.1 Government Documents

2.1.1 Specifications

FAA: Federal Aviation Administration

FAA-G-2100H Electronic Equipment, General Requirements. May 2005.

2.1.2 Standards

FAA-STD-019E Lightning and Surge Protection, Grounding, Bonding and Shielding

Requirements for Facilities and Electronic Equipment. December 2005.

FAA-STD-025E Preparation of Interface Documentation. August 2002.

HF-STD-001B Human Factors Design Standard, December 2016

Military:

MIL-STD-461G Requirements For The Control Of Electromagnetic Interference Characteristics of Subsystems and Equipment. December 2015.

MIL-STD-810G

Change 1

Department of Defense Test Method Standard. April 2014.

MIL-STD-889B

Change Notice 3

Dissimilar Metals. May 1993.

MIL-HDBK-454B

Notice 1

General Guidelines for Electronic Equipment. December 2012.

MIL-HDBK-217F

Change Notice 2

Reliability Prediction of Electronic Equipment. February 1995.

OSHA: Occupational Safety and Health Administration

29 CFR Part 1910 Occupational Safety and Health Standards: Subpart S, Electrical.

2.1.3 Other Government Documents

FAA Order

JO 6580.3

Remote Communications Facilities Installation Standards Handbook.

FCC: Federal Communications Commission

47 CFR Part 2 Frequency Allocations and Radio Treaty Matters; General Rules and

Regulations. October 2015.

47 CFR Part 15 Radio Frequency Devices. October 2015.

47 CFR Part 87 Aviation Services. October 2015.

NTIA: National Telecommunications and Information Administration

Redbook Manual of Regulations and Procedures for Federal Radio Frequency

Management. September 2017.

2.2 Non-Government Documents

IEEE/ANSI:

Institute of Electrical and Electronics Engineers/

American National Standards Institute

802.3-2018 IEEE Standard for Information Technology – Telecommunications and

Information Exchange between Systems – Local and Metropolitan area

Networks – Specific Requirements, Part 3: Carrier Sense Multiple Access with

Collision Detection (CSMA/CD) Access Method and Physical Layer

Specifications. August 2018.

C62.36-2000 IEEE Standard Test Methods for Surge Protectors Used in Low-Voltage Data, Communications, and Signaling Circuits. 2000.

C62.41.2-2002 IEEE Recommended Practice on Characterization of Surges in Low Voltage

(1000 V and Less) AC Power Circuits. 2002.

C62.45-2002 IEEE Recommended Practice on Surge Testing for Equipment Connected to

Low-Voltage (1000 V and Less) AC Power Circuits. 2002.

EIA: Electronic Industries Alliance

EIA/ECA-310-E Cabinets, Racks, Panels, and Associated Equipment. December 2005.

ETSI: European Telecommunications Standards Institute

EN-300-676-1

(V1.5.2)

Ground-based VHF Hand-Held, Mobile and Fixed Radio Transmitters, Receivers and Transceivers for the VHF Aeronautical Mobile Service Using

Amplitude Modulation; Part 1: Technical Characteristics and Methods of

Measurement. March 2011

EUROCAE: European Organisation for Civil Aviation Equipment

ED-136 Voice Over Internet Protocol (VoIP) Air Traffic Management (ATM) System

Operational and Technical Requirements. February 2009

ED-137C/1 Interoperability Standards for VoIP ATM Components, Volume 1 Radio. April

ED-137C/5 Interoperability Standard for VoIP ATM Components, Volume 5 Supervision.

April 2019

IEC: International Electrotechnical Commission

AS/NZS 60320.1 Appliance Couplers For Household And Similar General Purposes. 2004.

IEC 60320-1 Ed.2.1 Appliance Couplers for Household and Similar General Purposes – Part 1:

General Requirements. 2007.

IETF: Internet Engineering Task Force

RFC-791 Internet Protocol. September 1981.

RFC-1213 Management Information Base for Network Management of TCP/IP-based internets: MIB II

RFC-2131 Dynamic Host Configuration Protocol. March 1997.

RFC-2132 DHCP Options and BOOTP Vendor Extensions. March 1997.

RFC-2460 Internet Protocol, Version 6 (IPv6) Specification. December 1998.

RFC-2816 A Framework for Integrated Services Over Shared and Switched IEEE 802

LAN Technologies

RFC-2819 Remote Network Monitoring Management Information Base

RFC-3315 Dynamic Host Configuration Protocol for IPv6 (DHCPv6). July 2003.

RFC-3411 An Architect For Describing Simple Network Management Protocol (SNMP)

Management Frameworks

NFPA: National Fire Protection Association

NFPA 70 National Electric Code. 2008.

2.3 Documentation Sources

2.3.1 FAA Documents

Copies of FAA specifications, standards, and publications may be obtained from the NEXCOM

Contracting Officer, FAA, 800 Independence Avenue SW, Washington, DC 20591. Requests must clearly identify the desired material by number and state the intended use of the material.

The following documents are available for download from FAA Web pages.

HF-STD-001

http://hf.tc.faa.gov/hfds/.

2.3.2 Military and Federal Documents

Single copies of unclassified military and federal specifications, standards, and publications may be obtained by writing the Naval Publications and Forms Center, 5801 Tabor Avenue, Philadelphia, PA

19120, or by calling (215) 697-3321 Monday through Friday, 8:00 a.m. to 4:30 p.m. Eastern

Standard Time (EST). The following Department of Defense Web site offers military publications for download: http://quicksearch.dla.mil/. The following Web page offers guidance in identifying, locating, or acquiring U.S. military publications and documents:

http://www.loc.gov/rr/news/someplaces.html.

2.3.3 OSHA Documents

Copies of Occupational Safety & Health Administration (OSHA) documents may be obtained from the U.S. Department of Labor Occupational Safety & Health Administration, 200

Constitution Avenue, Washington, DC 20210. A copy of 29 CFR 1910 may be obtained from the following Web site at http://www.access.gpo.gov/cgi-bin/cfrassemble.cgi?title=199829.

2.3.4 FCC Documents

Copies of 47 CFR, Part 2, Part 15 and Part 87 may be obtained from the Federal Communica-tions Commission (FCC), 445 12th Street SW, Washington, DC 20554, or downloaded from the

Web at http://www.ecfr.gov/cgi-bin/text-idx?c=ecfr&tpl=/ecfrbrowse/Title47/47cfrv1_02.tpl

2.3.5 NTIA Documents

Copies of National Telecommunications and Information Administration (NTIA) materials may be obtained from NTIA, Department of Commerce, 14th Street and Constitution Avenue NW, Washington, DC 20230, or through the NTIA Web site at http://www.ntia.doc.gov. The Manual of Regulations and Procedures for Federal Radio Frequency Management, September 2017

Edition is available for download at https://www.ntia.doc.gov/page/2011/manual-regulations-and-procedures-federal-radio-frequency-management-redbook.

http://hf.tc.faa.gov/hfds/ http://quicksearch.dla.mil/ http://www.loc.gov/rr/news/someplaces.html http://www.access.gpo.gov/cgi-bin/cfrassemble.cgi?title=199829 http://www.ecfr.gov/cgi-bin/text-idx?c=ecfr&tpl=/ecfrbrowse/Title47/47cfrv1_02.tpl http://www.ntia.doc.gov/ https://www.ntia.doc.gov/page/2011/manual-regulations-and-procedures-federal-radio-frequency-management-redbook https://www.ntia.doc.gov/page/2011/manual-regulations-and-procedures-federal-radio-frequency-management-redbook

2.3.6 IEEE/ANSI Documents

Copies of Institute of Electrical and Electronics Engineers (IEEE) documents may be requested as follows: by mail at IEEE Customer Service, 445 Hoes Lane, Piscataway, NJ 08854-4141; by phone (800) 701-4333 (in the United States and Canada) or (732) 981-0060 (outside the United

States and Canada); or via the following Web site: http://www.ieee.org/web/standards/ home/index.html. The American National Standards Institute (ANSI) Web site is located at http://www.ansi.org.

2.3.7 EIA Documents

Copies of Electronic Industries Alliance (EIA) standards may be obtained from the Electronic

Industries Alliance, 2500 Wilson Boulevard, Arlington, VA 22201-3834, or by calling

(703) 907-7500, or via the Web at TBS.

2.3.8 ETSI Documents

Copies of European Telecommunications Standards Institute (ETSI) documents may be obtained from the ETSI Secretariat at F-06921 Sophia Antipolis CEDEX, France, or from the ETSI Web site at http://www.etsi.org/WebSite/Standards/Standard.aspx.

2.3.9 EUROCAE Documents

EUROCAE documents can be purchased via the Web at http://boutique.eurocae.net/catalog/ index.php. Special requests for printed copies should be made via e-mail to marie.potez@eurocae.net, or via telephone at +33 1 40 92 79 30.

2.3.10 IEC Documents

International Electrotechnical Commission (IEC) publications are available for purchase via the

Web at http://www.iec.ch. A standards search engine Web site is located at http://www.nssn.org.

2.3.11 IETF Documents

IETF documents are available for download from http://www.rfc-editor.org/rfc.html.

2.3.12 NFPA Documents

Copies of National Fire Protection Association (NFPA) documents may be obtained from NFPA, 1 Batterymarch Park, Quincy, MA 02169-7471. A copy of NFPA 70, National Electrical Code, may be purchased from the NFPA Web site at http://www.nfpa.org/aboutthecodes/

AboutTheCodes.asp?DocNum=70&cookie%5Ftest=1.

http://www.ieee.org/web/standards/home/index.html http://www.ieee.org/web/standards/home/index.html http://www.ansi.org/ http://www.etsi.org/WebSite/Standards/Standard.aspx http://boutique.eurocae.net/catalog/index.php http://boutique.eurocae.net/catalog/index.php mailto:marie.potez@eurocae.net http://www.iec.ch/ http://www.nssn.org/ http://www.rfc-editor.org/rfc.html http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=70&cookie%5Ftest=1 http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=70&cookie%5Ftest=1

3 REQUIREMENTS

3.1 Definitions

3.1.1 “Shall”

When used in this PD, the word “shall” refers to an explicit requirement of a system component or the complete system.

3.1.2 “Should”

When used in this PD, the word “should” refers to a desired characteristic of a system component or the complete system.

3.1.3 “Will”

When used in this PD, the word “will” provides information for a characteristic of a system component or a complete related system.

3.2 Radio Requirements

The technical characteristics described in this PD are for ground based VHF and UHF radio equipment and, unless otherwise specified, apply to both the receiver and transmitter equipment.

A receiver or a transmitter is considered to be a Line Replaceable Unit (LRU).

a) The radio equipment shall be implemented as individual UHF and VHF radios, i.e., no multiband implementations will be considered.

b) The radio equipment shall be implemented as individual receivers and transmitters, i.e., no transceivers will be considered.

c) The transmitter(s) shall be implemented as either individual low power and high power configurations, or as a single extended power range configuration (herein identified as a single enclosure) defined in Table 3-1.

d) The VHF high power transmitter should be implemented as defined by the desired operational features defined in Table 3-1.

e) A single enclosure transmitter shall be user configurable to be a low power or high power transmitter with all relevant range settings and parameters adjusted accordingly.

f) The radio equipment shall be implemented such that there is no less than one power supply per radio, i.e., a single power supply will not supply power for more than one radio.

g) All radio requirements shall be met under all operational modes, conditions, and over the frequency range(s) specified in this PD.

Note 1: All requirements within this PD apply to the respective transmit power configuration of the single enclosure transmitter unless otherwise stated, i.e., when the transmitter is configured as a low power transmitter it is expected to perform the same as if it were an individual low power transmitter.

Note 2 : The transmitter radio frequency (RF) output power level in Table 3-1 below defines the nominal power measured at the Antenna Transfer Relay (ATR) output port and accounts for losses incurred through the

ATR and in-line cavity filter. These values apply to individual low and high power transmitters or the single enclosure transmitter configured for the relevant power mode. See section 3.2.2.2.5 for additional details.

Table 3-1 Transmitter Nominal Radio Frequency Output Power Configurations

Case Low Power

Transmitter (W)

High Power

Transmitter (W)

VHF 12 35 or 55*

UHF 12 55

* Desired operational feature

3.2.1 Radio Functions and Software Requirements

3.2.1.1 Modes of Operation

a) The radio equipment shall operate in DSB-AM (see section 3.2.1.3) using 25 kHz channel spacing.

b) The VHF radio equipment shall operate in DSB-AM using 8.33 kHz channel spacing.

c) The VHF radio equipment shall be user configurable to allow the equipment to operate in either 25 kHz DSB-AM or 8.33 kHz DSB-AM channel spacing configuration.

d) The VHF radio equipment, when configured for 8.33 kHz channel spacing, shall operate in compliance with ETSI specification EN-300-676 (excluding sections 4.3 and 5).

Note: If a requirement in this PD conflicts with a requirement in ETSI specification EN-300-676, the requirement of this PD applies.

3.2.1.2 Tuning Ranges

a) The radio equipment shall be capable of tuning and operating at all frequencies within the relevant band as defined in Table 3-2.

Table 3-2 Tuning Ranges

Case

VHF (MHz) UHF (MHz)

25 kHz Channel

Spacing

8.33 kHz Channel

Spacing 25 kHz Channel Spacing

A 112.000 to 150.000 112.000 to 150.000 225.000 to 399.975

3.2.1.3 DSB-AM Modulation Method

a) The radio modulation method shall be A3E DSB-AM in accordance with FCC regulations in

47 CFR, Part 2, Frequency Allocations and Radio Treaty Matters; General Rules and

Regulations, October 2015; Part 87, Aviation Services, October 2015; and the NTIA Manual of Regulations and Procedures for Federal Radio Frequency Management, September 2017.

3.2.1.4 Firmware and Processor Requirements

a) The radio equipment, as separate entities, shall use no more than 50 percent of their non-volatile memory (as defined in section 6.2.15, Non-Volatile Memory) for storage under worst-case conditions (e.g., when the radio has both the software-in-use and a second software version loaded).

b) The radio equipment, as separate entities, shall use no more than 50 percent of their random-access memory (RAM), under worst-case conditions (e.g., when the radio has both the software-in-use and a second software version loaded).

c) Processor utilization of the receiver and transmitter, as separate entities, shall peak at 50 percent or less.

d) The radio equipment shall have an internal clock for event logging.

e) The radio equipment shall be software/firmware upgradeable.

f) The radio equipment shall allow local and remote software upload.

g) The radio equipment shall revert to the previous version of software, perform an automatic restart and return to the last operational state if a software upload is not successfully completed.

h) The radio equipment shall revert to the previous version of software, perform an automatic restart and return to the last operational state if transmitter software is inadvertently loaded onto a receiver.

Note 1: Simply stated, the radio must reject the software upload.

i) The radio equipment shall revert to the previous version of software, perform an automatic restart and return to the last operational state if receiver software is inadvertently loaded onto a transmitter.

Note 2: See Note 1.

j) If a software upload is rejected, the radio equipment shall send a control reply message indicating the reason for rejection.

k) The vendor shall specify the type(s) of non-volatile storage memory used (e.g., flash, EEPROM, battery backup), the minimum memory retention time for each component, and the procedures to follow to extend this time (e.g., rewriting contents, battery change).

l) All control parameters shall, upon initialization (as defined in section 6.2.11), assume their default values (as defined in section 3.2.3.2 Radio Control Parameters).

3.2.1.5 Radio Service Recovery

3.2.1.5.1 Automatic Radio Service Recovery

a) The radio equipment shall automatically recover from AC and DC power interruptions.

b) The radio equipment shall resume operational services after recovery from AC and DC power interruptions.

c) The radio equipment shall automatically restore operational service using the radio’s control parameter settings that were in effect prior to the electrical power service disruption.

3.2.1.5.2 User Invoked Radio Service Recovery

a) The radio equipment should support provisions that allow for factory and warm resets as defined in sections 6.2.12 and 6.2.13, respectively.

3.2.1.5.3 Radio Service Recovery Restoral Time

a) The receiver shall detect the presence of any RF signal at the antenna port, break squelch, demodulate, and process and present audio to the respective audio interface ports within 6 seconds of power reactivation from a facility service restoral.

b) The transmitter shall re-accept any push-to-talk (PTT) key from a respective PTT key interface, process any available audio stream, and modulate into an RF signal for transmission at the antenna port within 6 seconds of power reactivation from a facility service restoral.

3.2.2 Performance Requirements

3.2.2.1 Receiver Requirements

All receiver performance requirements will be validated using standard test signals as described in sections 4.1.1 and 4.1.3 of this PD unless otherwise stated.

3.2.2.1.1 Receiver Audio Interfaces

a) The receiver shall provide a remote analog audio output at the receiver remote interface connector (see section 3.3.1.3).

b) The receiver remote analog audio level shall be controllable via the Maintenance Data

Terminal (MDT).

c) The receiver remote analog audio level shall be controllable via the front panel interface (see section 3.3.1.3).

d) The receiver shall provide a local analog audio output to be used with a headset/headphone

(see section 3.3.1.6).

e) The local analog audio output level shall be independently controllable from the front panel via a control knob or the front panel interface (if implemented).

f) The receiver shall have a speaker on the front panel utilizing the local analog audio circuit.

g) The receiver speaker shall be disabled when the headset/headphone plug is inserted into the local audio output.

h) The remote and local analog audio outputs shall have a balanced 600 ohm (±10 percent) output impedance.

i) The receiver shall be capable of sending Voice over Internet Protocol (VoIP) audio data via the remote Internet Protocol (IP) interface (see section 3.2.4.1.1).

j) The receiver internal audio delay shall not exceed 20 ms as measured between the envelope of the modulated RF signal applied to the antenna input and the demodulated audio available at the analog audio outputs and the remote IP interface via VoIP.

Note 1: The terms local(ly) and remote(ly) are defined in sections 6.2.19 and 6.2.20, respectively.

Note 2: The receiver’s internal audio delay requirement is not to be misconstrued with the user-selectable voice packet size lengths supporting Voice Communications System (VCS) to Ground Radio Station (GRS) communications. VCS-to-GRS communicate using voice packets with sizes of 10ms, 20ms, and 30ms; with the default setting of 20ms.

Note 3: For verification of the receiver’s internal audio delay requirement, the radio packetization delay is included in the data measurement. Refer to Figure 27, Voice Delay: CWP-Antenna, of ED-137C Volume 1

Radio and Figure 11, Voice Delay Requirements (Ground Components), of ED-136, VoIP ATM System

Operation and Technical Requirements.

3.2.2.1.2 Receiver Sensitivity

a) The receiver RF input shall have 50 ohm characteristic impedance.

b) The receiver shall produce a SINAD of 10 dB or greater at the remote audio output when a rated desired signal between −102 dBm and −86 dBm is present at the receiver RF input.

Note: A rated desired signal is defined in section 4.1.1.2. SINAD is defined as the ratio of (Signal plus Noise plus Distortion) to (Noise plus Distortion).

3.2.2.1.3 Receiver Rejection of Signals Inside the Operating Bands

See section 3.2.2.1.17.

3.2.2.1.4 Receiver Selectivity

a) The selectivity of the receiver shall conform to Table 3-3 with respect to the tuned channel center frequency across the entire frequency band.

Note 1: VHF receivers are required to meet all the conditions in Cases A, B, and C.

Note 2: UHF receivers are required to meet the conditions in Cases A and B for 25 kHz channel spacing.

Table 3-3 Receiver Selectivity Profile

Case Level DSB-AM Bandwidth

(25 kHz Channel Spacing)

DSB-AM Bandwidth

(8.33 kHz Channel Spacing)

A −6.0 dB 9 kHz Minimum 3.5 kHz Minimum

B −60.0 dB 25 kHz Maximum 8.33 kHz Maximum

C −80.0 dB 50 kHz Maximum 25 kHz Maximum

3.2.2.1.5 Receiver Spurious Frequency Rejection

a) The VHF receiver shall not have image frequencies within the 112.000 MHz to 150.000

MHz band.

b) The UHF receiver should not have image frequencies within the 225.000 MHz to

399.975 MHz frequency band.

c) The sensitivity requirements of section 3.2.2.1.2 shall not be degraded by more than 3 dB in the presence of an undesired signal as specified in Table 3-4 for the relevant receiver type.

Note: Collocation testing will not be conducted where the frequency of the interfering signal is coincidental with a known spurious response frequency.

Table 3-4 Receiver Spurious Frequency Rejection Undesired Signal

Case Undesired

Modulation

Undesired Signal

Level (dBm) Undesired Frequencies

VHF CW* −22

All spurious response frequencies including receiver image frequencies

UHF CW* −32 Any image frequency

* Continuous Wave

3.2.2.1.6 Receiver Distortion

3.2.2.1.6.1 Receiver Intermodulation

a) The sensitivity requirements defined in section 3.2.2.1.2 shall not be degraded by more than

3 dB in the presence of two undesired signals as defined in Case A of Table 3-5, with frequencies chosen such that one of the 3rd order products is located on the receiver operating frequency.

b) The sensitivity requirements defined in section 3.2.2.1.2 shall not be degraded by more than

3 dB in the presence of two undesired signals as defined in Case B of Table 3-5, with frequencies chosen such that one of the 3rd order products is located on the receiver operating frequency.

c) The sensitivity requirements defined in section 3.2.2.1.2 shall not be degraded by more than

3 dB in the presence of two undesired signals as defined in Case C of Table 3-5, with the frequencies of the undesired signals offset from the receiver operating frequency by +2.0

MHz and +4.0 MHz, or –2.0 MHz and –4.0 MHz, respectively.

d) The sensitivity requirements defined in section 3.2.2.1.2 shall not be degraded by more than

3 dB in the presence of two undesired signals as defined in Case D of Table 3-5, with frequencies chosen such that the 2nd order products are located on the chosen UHF receiver operating frequency.

Note 1: VHF and UHF receivers are required to meet Cases A through C.

Note 2: UHF receivers are required to meet Case D.

Table 3-5 Receiver Intermodulation Undesired Signals

Case Undesired Signal #1

Modulation

Undesired Signal #2

Modulation

Undesired

Signal Levels

(dBm)

Undesired

Frequency Band

(MHz)

A FM, 404 Hz tone with

75 kHz Deviation

FM - 404 Hz tone with

75 kHz Deviation −5 87.5 to 107.9

B FM, 404 Hz tone with

75 kHz Deviation CW +5 87.5 to 107.9

C DSB-AM, 404 Hz tone at 90%

DSB-AM – 404 Hz tone at 90% −30 Operating Band

D DSB-AM, 404 Hz tone at 30% CW +5 118.000 to 136.975

3.2.2.1.6.2 Receiver Cross Modulation

a) The sensitivity requirements defined in section 3.2.2.1.2 shall not be degraded by more than

2 dB in the presence of a standard undesired signal separated by ±0.5 MHz and at a level

70.0 dB above the rated desired signal.

b) The sensitivity requirements defined in section 3.2.2.1.2 shall not be degraded by more than

2 dB in the presence of a standard undesired signal separated by ±1.0 MHz and at a level

75.0 dB above the rated desired signal.

c) The sensitivity requirements defined in section 3.2.2.1.2 shall not be degraded by more than

2 dB in the presence of a standard undesired signal separated by ±1.5 MHz and at a level

80.0 dB above the rated desired signal.

Note: A standard undesired signal is defined in section 4.1.1.4.

3.2.2.1.7 Receiver Frequency Tolerance

a) The frequency tolerance of the receiver reference frequency shall be within 0.0001 percent

(1 ppm) of its reference value for a period of one year following alignment over the full frequency range specified in section 3.2.1.2, and the temperature range specified in section

3.4.3.2 (Operating Conditions).

b) The reference used to generate the receiver operating frequency shall have a tuning adjustment to compensate for aging during the operational life of the equipment.

c) The receiver operating frequency shall be adjustable to within 1 ppm of the tuned channel center frequency.

d) The external reference frequency monitor port shall have an impedance of 50 ohms.

e) The external reference frequency monitor port shall have a reference signal level greater than or equal to −20 dBm.

f) The receiver shall provide an output of the reference frequency signal for measurement, testing and alignment.

g) The reference signal monitor port shall be sufficiently isolated such that a short circuit applied from the monitor port to ground does not degrade the radio performance as specified in sections 3.2.2.1, Receiver Requirements.

3.2.2.1.8 Receiver Audio Output Control

a) The remote audio output level of the receiver shall be adjustable in the range between

−25 dBm (−0/+1 dB) and +20 dBm (−0/+2 dB) in the presence of a standard desired signal.

b) The remote audio output level of the receiver shall be adjustable in steps smaller than 0.5 dB.

c) The remote audio output level of the receiver should be adjustable in steps smaller than 0.25 dB.

d) The local audio output level of the receiver shall be adjustable in the range between

−25 dBm (−0/+1 dB) and +20 dBm (−0/+2 dB).

e) The local audio output level of the receiver should be adjustable in steps smaller than 0.5 dB.

3.2.2.1.9 Receiver Audio Level Regulation

a) The remote audio output level of the receiver (adjusted for rated audio output power) shall not vary more than ±1.0 dB as a standard desired signal's modulation is increased from 30 to

100 percent.

b) The remote audio output level of the receiver (adjusted for rated audio output power) shall not drop more than 4.0 dB when the load resistance is reduced from 600 to 120 ohms.

Note: The rated audio output power is defined in section 4.1.1.6.

3.2.2.1.10 Receiver Audio Automatic Level Stabilization

a) The remote audio output level of the receiver (adjusted for standard audio output power) shall not vary by more than ±3 dB from a reference audio level for any standard desired signal between −98 dBm and −7 dBm.

Note: The reference audio level is measured with a −50 dBm standard desired signal. The standard audio output is defined in section 4.1.1.7.

3.2.2.1.11 Receiver Audio Mute and Attenuation

a) The receiver shall have a control parameter for muting the receiver remote audio output.

b) The receiver shall have a discrete analog input for muting the receiver remote audio output.

c) The receiver mute feature shall have provisions to be enabled or disabled both locally and remotely.

d) The attenuation level for the muting function shall be selectable from −15 dB, −20 dB, or no audio (no audio is defined as at least 80 dB down from a reference level of +20 dBm).

e) The tolerances for the -15 dB and -20 dB selectable attenuation shall be 2 dB.

f) The default for the selectable attenuation shall be no audio.

g) The muting signal should have an attack time no greater than 10 ms.

h) The receiver should allow a delayed release of the mute attenuation signal.

i) The receiver mute release delay should be configurable from 0 to 250 ms.

j) The receiver mute release delay should be adjustable in increments not to exceed 25 ms.

k) The receiver audio shall be muted when either the control parameter or the input from the receiver remote interface indicate audio muting, and unmute when both indicate no mute.

l) The receiver shall provide a confirmation signal via the receiver remote interface for the duration of the mute.

3.2.2.1.12 Receiver Average Audio Output

a) The remote audio output level of the receiver (adjusted for standard audio output power using a reference desired signal) shall be −13 dBm (±2 dB) averaged over 3 seconds in the presence of a −87 dBm signal, AM modulated at 90 percent using a Government furnished speech sample.

b) The peak remote audio output level of the receiver (adjusted for standard audio output power using a reference desired signal) shall not exceed 0 dBm in the presence of a −87 dBm signal, AM modulated at 90 percent using a Government furnished speech sample.

Note: The reference desired signal is defined as a −87 dBm carrier, amplitude modulated with a 1004 Hz sine wave to a depth of 30 percent. The Government furnished speech sample will be made available prior to release of the final Screening Information Request (SIR).

3.2.2.1.13 Receiver Audio Distortion

a) The remote audio output shall not be distorted by more than 2.0 percent in the presence of a standard desired signal for 30 percent modulation with any RF input level between −67 dBm and −27 dBm, for any input tones within the rated audio band for the relevant channel spacing configuration.

b) The remote audio output shall not be distorted by more than 5.0 percent for 90 percent modulation with any RF input level between −67 dBm and −27 dBm, for any input tones within the rated audio band for the relevant channel spacing configuration.

Note: The rated audio band is defined in section 4.1.1.8.

3.2.2.1.14 Receiver Audio Frequency Response

a) The remote audio output level shall not vary by more than ±2.0 dB from the level achieved with a reference desired signal (see note) when the reference audio input frequency is varied within the rated audio band.

b) The remote audio output level shall decrease monotonically from the level achieved with a reference desired signal as the frequency increases between the ranges indicated by the high frequency rejection band in Table 3-6.

c) The remote audio output level shall be at least 20.0 dB down from the level achieved with a reference desired signal at frequencies indicated by the ultimate frequency rejection band of

Table 3-6.

d) The remote audio output level shall decrease monotonically from the level achieved with a reference desired signal as the audio frequency decreases between the ranges indicated in the low frequency rejection band of Table 3-6 and be down at least 10.0 dB at 100 Hz.

Note: The reference desired signal is defined as a -102 dBm to -7 dBm carrier, amplitude modulated with a

1004 Hz tone to a depth of 90 percent.

Table 3-6 Receiver Audio Frequency Response Audio Bands

Channel

Spacing

(kHz)

Low Frequency

Rejection Band

(Hz)

Audio Pass

Band

(Hz)

High Frequency

Rejection Band

(Hz)

Ultimate Frequency

Rejection Band

(Hz)

25 0 to 300 300 to 3000 3000 to 10000 10000+

8.33 0 to 350 350 to 2500 2500 to 10000 10000+

3.2.2.1.15 Receiver Squelch

3.2.2.1.15.1 Squelch

a) The receiver shall have a squelch system consisting of both an RF level threshold (herein defined as carrier squelch) and an audio signal-to-noise threshold (herein defined as noise squelch).

b) The receiver audio output level shall be at least 90 dB down from a reference level of +20 dBm when the receiver is set for squelch-enabled condition and in the presence of an input

RF signal level less than the squelch RF threshold level.

c) The receiver remote audio level transients shall be 20.0 dB below the audio alignment level under any operating condition or configuration with the alignment level ranging between

−25 dBm to +20 dBm.

d) The carrier squelch feature shall have provisions to be enabled and disabled both locally and remotely.

e) The noise squelch feature shall have provisions to be enabled and disabled both locally and remotely.

3.2.2.1.15.2 Receiver Squelch Adjustment, Sensitivity, and Hysteresis

a) If both the RF Carrier Squelch feature and Audio Signal-to-Noise Squelch feature are enabled, then the receiver remote and local audio shall be enabled when the received signal exceeds both the RF carrier power, and audio signal-to-noise ratio threshold values defined in c) and d) below.

b) The squelch sensitivity, for the RF Carrier Squelch and Audio Signal-to-Noise Squelch features, shall be adjustable both locally and remotely.

c) The Audio Signal-to-Noise Squelch threshold value shall be adjustable in the range of +5 dB to +15 dB in the presence of a DSB-AM signal modulated 30 percent with a 1004 Hz tone.

d) The RF Carrier Squelch threshold level shall be adjustable in 1 dB steps or less in the range from –102 dBm to –65 dBm.

e) The RF Carrier Squelch closing hysteresis shall be not less than 2 dB and not greater than 7 dB with respect to the receiver carrier squelch threshold value.

f) If the Audio Signal-to-Noise Squelch feature is enabled and the RF Carrier Squelch feature is disabled, then the receiver remote and local audio shall be enabled when the received signal exceeds the audio signal-to-noise ratio threshold value defined in c) above.

g) If the RF Carrier Squelch feature is enabled and the Audio Signal-to-Noise Squelch feature is disabled, then the receiver remote and local audio shall be enabled when the received signal exceeds the RF carrier power threshold value defined in d) above.

3.2.2.1.15.3 Receiver Squelch Attack and Release Times

a) The squelch attack time shall not exceed 20 ms with any standard desired signal with an RF level between −102 dBm and −7 dBm.

b) The squelch attack time should not exceed 10 ms with any standard desired signal with an

RF level between −102 dBm and −7 dBm.

c) The squelch release time shall not exceed 35 ms.

Note: For verification of these requirements, the receiver internal audio delay value, up to the limit defined in section 3.2.2.1.1.j, will be subtracted from the raw squelch attack and release time measurements.

3.2.2.1.16 Collocation

a) The sensitivity requirements defined in section 3.2.2.1.2 shall not be degraded by more than a specified value in the presence of a transmitter, configured to be a standard undesired signal except with an AM Depth of 90%, set for rated output power (see section 4.1.2.4), when the transmit-receive frequency separation and path isolation are as defined in Table

3-7.

Note 1: VHF radios are only required to meet Cases A and B from 112.000 MHz to 136.975 MHz, with up to

4dB of additional allowable degradation between 137.000 MHz and 150.000 MHz.

Note 2: UHF radios are only required to meet Case C.

Note 3: Collocation testing will not be conducted where the frequency of the interfering signal is coincidental with a known spurious response frequency.

b) The sensitivity requirements defined in section 3.2.2.1.2 for the UHF receiver should not be degraded by more than a specified value in the presence of a transmitter, configured to be a standard undesired signal set for rated output power, when the transmit-receive frequency separation and path isolation are as defined in Case D of Table 3-7.

Table 3-7 Receiver Collocation Cases

Isolation/Separation Allowable Degradation (dB)

Case Isolation

(dB)

Separation

(MHz)

Low Power

TX

High Power

TX

A 42 ≥0.5 10 16

B 28 ≥ 2.0 10 16

C 31 ≥3.1 7 14

D 31 ≥2.0 14 21

3.2.2.1.17 Receiver Adjacent Channel Rejection

a) The sensitivity requirements of section 3.2.2.1.2 shall not be degraded by more than 3 dB in the presence of a −63 dBm adjacent channel (centered on 25 kHz or 8.33 kHz for VHF or

25 kHz for UHF) undesired signal, AM modulated 90 percent with a 404 Hz tone.

3.2.2.1.18 Receiver Rejection of Signals Outside the Operating Bands

a) The sensitivity requirements of section 3.2.2.1.2 shall not be degraded by more than 2 dB in the presence of an undesired signal as defined in Table 3-8.

b) The sensitivity requirements of section 3.2.2.1.2 should not be degraded by more than 2 dB in the presence of an undesired signal as defined by the desired frequency band for the VHF case in Table 3-8.

Table 3-8 Receiver Rejection of Signals Outside the Band Undesired Signal Cases

Level Modulation Frequency Range

VHF 0 dBm Continuous Wave All frequencies below and above 109 to

153 MHz, respectively

UHF 0 dBm Continuous Wave All frequencies below and above 222 to

403 MHz, respectively

3.2.2.1.19 Receiver Desired Signal Dynamic Range

a) The receiver shall achieve a SINAD of 10 dB or greater in the presence of any standard desired signal modulated 90 percent at any RF level ranging from –102 dBm up to –7 dBm.

b) The receiver shall not be blocked in the presence of any standard desired signal modulated

90 percent at any RF level up to +13 dBm.

c) The receiver shall not be damaged due to the presence of any standard desired signal, modulated to a depth of 90 percent at RF levels up to +25 dBm, for a duration of 5 minutes or less.

Note: Blocking is defined as a 3 dB reduction in the audio level referenced to the audio level setting at the desired signal input of –7 dBm modulated 90 percent with a 1004 Hz tone.

3.2.2.1.20 Receiver Automatic Gain Control (AGC) Stabilization

a) The sensitivity requirements of section 3.2.2.1.2 shall not be degraded by more than a specified level not later than the required attack time after insertion of a specified undesired signal.

b) The sensitivity requirements of section 3.2.2.1.2 shall be met not later than 150 ms after removal of an undesired signal as defined in Table 3-9.

Note 1: The undesired signal, allowable degradation in sensitivity, and attack time are defined in Table 3-9.

Note 2: For verification of these requirements, the receiver internal audio delay value, up to the limit defined in section 3.2.2.1.1.j, will be subtracted from the raw AGC attack and release time measurements.

Table 3-9 Receiver Automatic Gain Control (AGC) Stabilization Undesired Signal

Undesired Signal

Allowable

Degradation in Sensitivity

(dB)

Required

Attack

Time

(ms)

VHF

+14 dBm carrier, continuous wave, 2 MHz from the desired frequency 10 30

UHF

+9 dBm carrier, continuous wave, 3.1 MHz from the desired frequency 7 20

3.2.2.1.21 Receiver Internal Noise Level

a) The receiver audio output SINAD shall be 25 dB or greater in the presence of a −85 dBm standard desired signal.

3.2.2.1.22 Receive Signal Strength Indicator (RSSI)

a) The receiver shall provide a Receive Signal Strength Indicator (RSSI) to the radio control equipment/voice switch.

3.2.2.2 Transmitter Requirements

All transmitter performance requirements will be validated using standard test signals as described in sections 4.1.2 and 4.1.3 of this PD unless otherwise stated.

3.2.2.2.1 Transmitter Audio Interfaces

a) The transmitter shall provide a remote analog audio input at the transmitter remote interface connector (see section 3.3.1.4).

b) The remote audio input shall have a balanced 600 ohm (±10 percent) impedance.

c) The remote audio input shall accept signals at input levels and frequencies specified in Table

3-10.

Table 3-10 Transmitter Audio Input Signal Ranges

Channel Spacing

(kHz)

Audio Frequency

Range (Hz)

Audio Input

Level (dBm)

25 300 to 3000 −25.0 to +20

8.33 350 to 2500 −25.0 to +20

d) The transmission of the remote audio input shall be controlled via a keying signal originating from the control site.

e) The transmitter shall provide a local analog audio input to be used with a microphone (see section 0).

f) The transmission of the local analog audio input shall be controlled via a push-to-talk microphone.

g) The transmitter shall accept VoIP audio input via the remote IP interface.

h) Only one transmitter audio input (local, remote or VoIP) shall be active at one time.

i) The transmitter internal audio delay shallnot exceed 10 ms as measured between the analog audio inputs or the remote IP interface via VoIP and the envelope of the modulated RF signal at the antenna output port.

Note 1: The transmitter’s internal audio delay requirement is not to be misconstrued with the user-selectable voice packet size lengths supporting Voice Communications System (VCS) to Ground Radio Station (GRS) communications. VCS-to-GRS communicate using voice packets with sizes of 10ms, 20ms, and 30ms; with the default setting of 20ms.

Note 2: For verification of the transmitter’s internal audio delay requirement, jitter buffer, which is variable in a

SIP session, is excluded from the data measurement. Refer to Figure 27, Voice Delay: CWP-Antenna, of ED-

137C Volume 1 Radio and Figure 11, Voice Delay Requirements (Ground Components), of ED-136, VoIP

ATM System Operation and Technical Requirements.

3.2.2.2.2 Transmitter Time-Out

a) The transmitter shall contain a time-out function for protection against, and the elimination of, extended periods of continuous keying.

b) The adjustable transmitter time-out shall range from 5 seconds up to 5 minutes in 5-second steps (limiting the maximum continuous keying of the transmitter to this time period).

c) The time-out feature shall have provisions for being disabled (see section 3.2.3), both locally and remotely, to allow the transmitter unlimited continuous transmit operation.

d) The transmitter shall cease radiating upon time-out until the input key signal is…