NEXV3 SIR Sect J_Att J01_PD_v2.5_FAA-E-37021.docx

DEPARTMENT OF TRANSPORTATION

FEDERAL AVIATION ADMINISTRATION

PRODUCT DESCRIPTION (PD)

NEXCOM Version 3 (V3)

ULTRA HIGH FREQUENCY (UHF) RECEIVERS AND TRANSMITTERS

VERY HIGH FREQUENCY (VHF) RECEIVERS AND TRANSMITTERS

Air/Ground Voice Communications (AGVC) Team, AJM-313

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

RECORD OF CHANGES

TABLE OF CONTENTS

LIST OF TABLES

LIST OF FIGURES

LIST OF APPENDICES

FAA-E-37021

February 28, 2023 V 2.5

SCOPE

Identification This document contains the Product Description (PD) for the NEXt generation Air/Ground (A/G) COMmunications (NEXCOM) Version 3 (V3) System Ultra High Frequency (UHF) and Very High Frequency (VHF) Radios. This NEXCOM V3 Radio PD describes the functions and performance requirements necessary for the radio equipment to satisfy the NEXCOM V3 Radio deployment. All requirements in this PD are common to both the UHF and VHF radios unless the requirement specifically addresses a particular radio.

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 V3 Radio Program will replace current UHF/VHF ground-based analog radios at Remote Center Air/Ground (RCAG) and Back-Up Emergency Communications (BUEC) facilities supporting en route Communications.

NEXCOM V3 Radios will operate using the current 25 kHz channel-spacing assignment in the UHF and VHF radio frequency (RF) bands. Both RF bands 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.

NEXCOM V3 radios will be physically compatible with today’s existing NAS equipment, will be equipped with a legacy analog audio interface(s) as well as an ED-137C/1 compliant Internet Protocol (IP)-based audio interface(s) supporting future NAS gateway subsystems and components.

APPLICABLE DOCUMENTS

The following documents form a part of this NEXCOM V3 Radio PD to the extent 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 will take precedence.

Government Documents Specification

Standards

Military:

MIL-HDBK-217F

Change Notice 2 Reliability Prediction of Electronic Equipment. February 1995.

Other Government Documents

FAA Order

JO 6580.3

Remote Communications Facilities Installation Standards Handbook.

Non-Government Documents

December 2005.

Volume 1 Radio. April 2017

ED-137C/1,

Change 1 Interoperability Standards for VoIP ATM Components, Volume 1 Radio, Change 1. May 2020

Volume 4 Recording. March 2019

ED-137C/4,

Change 1 Interoperability Standards for VoIP ATM Components, Volume 4 Recording, Change 1. May 2020

Volume 5 Supervision. April 2019

American National Standards Institute

Document Sources FAA Specifications and Standards Copies of FAA specifications, standards, and publications may be obtained from the NEXCOM Contracting Officer. Requests will clearly identify the desired material by number and state the intended use of the material.

The following Web pages offers publications for download: http://hf.tc.faa.gov/hfds/ and http://everyspec.com/FAA.

Military Standards 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.

Other Government Documents DOE Documents Copies of Department of Energy (DOE) document 10 CFR Part 20 can be downloaded from the Web at https://www.ecfr.gov/current/title-10/chapter-I/part-20.

FCC Documents Copies of Federal Communications Commission (FCC) documents 47 CFR, Part 2, Part 15 and Part 87 may be obtained from the Federal Communications Commission (FCC), 445 12th Street SW, Washington, DC 20554, or downloaded from the Web at https://www.ecfr.gov/current/title-47.

FDA Documents Copies of Food and Drug Administration (FDA) document 21 CFR Part 1040 can be downloaded from the Web at https://www.ecfr.gov/current/title-21/chapter-I/subchapter-J/part-1040.

FEMA Documents Copies of Federal Emergency Management Agency (FEMA) documents can be downloaded from the Web at https://www.nehrp.gov/library/index.htm.

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.

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 https://www.osha.gov/laws-regs/regulations/standardnumber/1910.

Non- Government Documents EIA Documents Copies of Electronic Industries Alliance (EIA) standards may be obtained from https://global.ihs.com/standards.cfm?publisher=ECIA.

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 https://www.etsi.org/index.php/standards#Pre-defined%20Collections.

EUROCAE Documents ED-137C Interoperability Standards for VoIP ATM Components, Volume 1 Radio requirements and its related Change 1 requirements, as applicable, are collectively referred to as ED-137C/1 hereafter. ED-137C Interoperability Standards for VoIP ATM Components, Volume 4 Recording requirements and its related Change 1 requirements, as applicable, are collectively referred to as ED-137C/4 hereafter. ED-137C Interoperability Standards for VoIP ATM Components, Volume 5 Supervision requirements is referred to as ED-137C/5 hereafter. EUROCAE documents can be purchased via the Web at https://eshop.eurocae.net.

ICC Documents International Code Council (ICC) publications are available for purchase via the Web at https://www.iccsafe.org/.

IEC Documents International Electrotechnical Commission (IEC) publications are available for purchase via the Web at http://www.iec.ch.

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: https://www.ieee.org/publications/index.html. The American National Standards Institute (ANSI) Web site is located at http://www.ansi.org.

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

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.

REQUIREMENTS

Definitions “Shall” When used in this PD, the word “shall” refers to a compulsory requirement of a system-component, parameter or the complete system.

“Should” When used in this PD, the word “should” refers to a desired, but not a compulsory, requirement of a system-component, parameter or the complete system.

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

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 shall1 be implemented as individual UHF and VHF radios or as multiband UHF/VHF radios1.

b) The radio equipment shall2 be implemented as individual receivers and transmitters, i.e., no transceivers will be considered.

c) The transmitter(s) shall3 be implemented as either individual low power and high power configurations,1,3 or as an extended power transmitter configuration,1,2,3 as defined in Table 31 and Table 311.

d) The UHF high power transmitter,1,2,3 or UHF extended power transmitter,1,2,3 should1 be implemented as defined by the desired operational output power function in Table 31 and Table 311.

e) If implemented, an extended power transmitter configuration,1,2,3 shall4 have a control parameter for configuring low power or high power modes as defined in Table 316.

f) If implemented, an extended power transmitter configuration,1,2,3 shall5 have a control parameter for configuring a RF Output Power Level Low Threshold as defined in ED-137C/5 ANNEX A3 Management Information Base (MIB).

g) If implemented, an extended power transmitter configuration,1,2,3 shall6 have a control parameter for configuring a RF Output Power Level High Threshold as defined in ED-137C/5 ANNEX A3 MIB.

h) The VHF transmitter(s) shall7 have a control parameter for adjusting the CLIMAX Offset as defined in ED-137C/5 ANNEX A3 MIB.

i) The VHF transmitter(s) should2 have a control parameter with the CLIMAX Offset default setting as defined in Table 317.

j) The radio equipment shall8 be implemented such that each individual radio has its own power supply.

k) All radio requirements shall9 be met under all operational modes, conditions, and over the frequency range(s) specified in this PD.1,2,3 Note 1: Multiband radios can be used to fulfill the VHF band or UHF band requirements; however, it is expected that all compulsory equipment size and ratios requirements defined in section 3.4.1.2 will be met.

Note 2: All requirements within this PD apply to the respective transmit power configuration of an extended power transmitter unless otherwise stated, i.e., when the extended power transmitter is configured as a low power transmitter it is expected to perform the same as if it were an individual low power transmitter and when configured as a high power transmitter it is expected to perform the same as if it were an individual high power transmitter.

Note 3: The transmitter radio frequency (RF) output power level in Table 31 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 extended power transmitter configured for the relevant power mode. See section 3.2.2.2.5 and Table 311 for additional details.

Table 31: Transmitter Nominal Radio Frequency Output Power Configurations

(12 to 50)* 2 to 35 or (2 to 50)*

* Desired operational function

Radio Functions and Software Requirements Modes of Operation

a) The radio equipment shall10 operate in DSB-AM (see section 3.2.1.3) using 25 kHz channel spacing.

b) The VHF radio equipment shall11 operate in DSB-AM using 8.33 kHz channel spacing.

c) The VHF radio equipment shall12 be user configurable to allow the equipment to operate in either 25 kHz DSB-AM or 8.33 kHz DSB-AM channel spacing.

d) The VHF radio equipment, when configured for 8.33 kHz channel spacing, shall13 operate in compliance with ETSI specification EN-300-6761 (excluding ETSI sections 4.3 and 5).

Note 1: If a requirement in this PD conflicts with a requirement in ETSI specification EN-300-676, the requirement of this PD will take precedence.

Tuning Ranges

a) The radio equipment shall14 be capable of tuning and operating at all frequencies within the relevant band as defined in Table 32.

b) The radio equipment shall15 have a control parameter for configuring all frequencies within the relevant band as defined in ED-137C/5 ANNEX A3 MIB (i.e., Nominal Frequency or Current Frequency).

c) The radio equipment should3 have a control parameter with default settings for UHF and VHF frequencies as defined in Table 317.

d) The radio equipment shall16 have a control parameter for channel spacing within the VHF band as defined in ED-137C/5 ANNEX A3 MIB (i.e., Frequency Spacing or Channel Spacing).

e) The radio equipment should4 have a control parameter with a default setting for VHF channel spacing as defined in Table 317.

f) The radio equipment should5 have a control parameter for tuning the Lowest Tunable Frequency, within the VHF band, as defined in Table 318.

g) The radio equipment should6 have a control parameter for tuning the Highest Tunable Frequency, within the VHF band, as defined in Table 318.

Table 32: Tuning Ranges

DSB-AM Modulation Method

a) The radio modulation method shall17 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.

Firmware, Processor, Software Upload and Switchover Requirements

a) The radio equipment shall18 be software/firmware (SWFW) upgradeable.

b) The radio equipment shall19 allow local and remote radio SWFW uploads.

c) The radio equipment, as separate entities, shall20 use no more than 50 percent of their non-volatile memory (as defined in section 6.14, Non-Volatile Memory) for storage under worst-case conditions (e.g., when a radio has SWFW active (in-use) and other SWFW version(s) is/are loaded).

d) The radio equipment, as separate entities, shall21 use no more than 50 percent of their random-access memory (RAM), under worst-case conditions (e.g., when a radio has the SWFW active (in-use) and other SWFW version(s) is/are loaded).

e) The peak utilization of the available resources of each processor within receivers and transmitters, inclusive of Digital Signal Processors (DSPs) and Field Programmable Gate Arrays (FPGAs), shall22 not exceed 50% when placed under its maximum usage1.

f) The radio equipment shall23 support a configurable number of concurrent Session Initiation Protocol (SIP) sessions.

g) The radio equipment shall24 support a minimum of 7 concurrent SIP sessions.

h) The radio equipment shall25 have an internal clock for event logging.

i) Any new radio SWFW upload shall26 not overwrite the designated active radio SWFW version.

j) The switchover to the new uploaded radio SWFW version shall27 only occur upon receipt of a manual radio SWFW switchover command.

k) All existing and current radio settings shall28 be retained during a radio SWFW switchover process.

l) Any new settings introduced in a new radio SWFW version, meaning not present in a previous radio SWFW version, shall29 take their default setting after the radio SWFW switchover process.

m) During the radio SWFW switchover process, the new uploaded radio SWFW version shall30 become the active radio SWFW version, while the prior active SWFW version becomes the previous SWFW version.

n) The radio SWFW switchover process shall31 prevent transmitters from switching to a SWFW version intended for a receiver.

o) The radio SWFW switchover process shall32 prevent receivers from switching to a SWFW version intended for a transmitter.

p) If a switchover to the new radio SWFW version is unsuccessful or rejected, the radio shall33 revert to, or remain with, the previous version of the radio SWFW, perform a Warm Reset, if needed, and return to the last operational state.

q) The time to perform a switchover between SWFW versions within the radio equipment should7 be 3 minutes or less.

Note 1: The maximum usage is defined as the maximum load on the radios’ processors when handling maximum number of SIP/RTP sessions, at least 1 SNMPv3 session and 1 recording session (if the recording interface is present).

Radio Service Recovery Automatic Radio Service Recovery

a) The radio equipment shall34 automatically recover from AC and DC power interruptions.

b) The radio equipment shall35 resume operational services after recovery from AC and DC power interruptions.

c) The radio equipment shall36 automatically restore operational service using the radio’s monitoring and control parameter settings that were in effect prior to the electrical power service disruption.

User Invoked Radio Service Recovery

a) The radio equipment shall37 have a Factory Reset, as defined in section 6.11, that is user-invoked via the front panel interface (see section 3.2.3.2.1).

b) The radio equipment shall38 have a control parameter for a Warm Reset as defined in Table 316 and in section 6.12.

Radio Service Recovery Restoral Time

a) The receiver shall39 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, or be ready to respond to VoIP protocol handshaking requests using a static IP address, within 6 seconds of power reactivation1 from a facility service restoral.

b) The transmitter shall40 re-accept any analog (discrete) push-to-talk (PTT) key from a respective PTT key interface, process any analog audio stream, and modulate an analog stream onto an RF carrier for transmission at the antenna port within 6 seconds of power reactivation1 from a facility service restoral, or be ready to respond to VoIP protocol handshaking requests using a static IP address within 6 seconds of power reactivation1 from a facility service restoral.

Note 1: Power reactivation from a facility service restoral (i.e., restoral of AC and/or DC after the loss or interruption of both AC and DC) corresponds to the radio boot time after a cold start (i.e. switch on of the radio).

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

Receiver Audio Interfaces

a) The receiver shall41 provide a remote1 analog audio output at the receiver remote interface connector (see section 3.3.1.8).

b) The receiver remote analog audio level shall42 be controllable via the Maintenance Data Terminal (MDT).

c) The receiver remote analog audio level shall43 be controllable via the front panel interface (see section 3.2.3.2.1).

d) The receiver shall44 provide a local analog audio output to be used with a headset/headphone (see section 3.3.1.11).

e) The local1 analog audio output level shall45 be independently controllable from the front panel via a control knob or the front panel interface (if implemented).

f) The receiver shall46 have a speaker on the front panel utilizing the local analog audio circuit.

g) The receiver speaker should8 be disabled when the headset/headphone plug is inserted into the local audio output.

h) The remote analog audio output shall47 have a balanced 600 ohm (±10 percent) output impedance.

i) The local analog audio output shall48 provide audio levels of sufficient amplitude, to allow for monitoring of voice traffic, when terminated with headphone impedances in the range of 30 to 600 ohms.

j) The receiver shall49 be capable of sending VoIP audio data via the remote Internet Protocol (IP) interface (see section 3.2.4.3).

k) The receiver internal audio delay shall50 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 6.18 and 6.19, 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, when in VoIP mode, the radio packetization delay will be excluded from the data measurement. Refer to Figure 11, Voice Delay Requirements (Ground Components), of ED-136, VoIP ATM System Operation and Technical Requirements.

Receiver Sensitivity

a) The receiver RF input shall51 have 50 ohm normal load1 characteristic impedance.

b) The receiver shall52 produce a SINAD of 10 dB or greater at the remote audio output when a standard desired signal of no more than −102 dBm is present at the receiver RF input2.

Note 1: The term normal load is defined in section 4.1.4.

Note 2: A desired signal of -102 dBm is herein defined as the rated desired signal (see section 4.1.1.2). SINAD is defined as the ratio of (Signal plus Noise plus Distortion) to (Noise plus Distortion).

Receiver Rejection of Signals Inside the Operating Bands See section 3.2.2.1.17.

Receiver Selectivity

a) The selectivity of the receiver shall53 conform to Table 33 with respect to the tuned channel center frequency across the entire frequency band.

Table 33: Receiver Selectivity Profile

(25 kHz Channel Spacing) DSB-AM Bandwidth (8.33 kHz Channel Spacing)

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.

Receiver Spurious Frequency Rejection

a) The VHF receiver should9 not have image frequencies within the 112.000 MHz to 150.000 MHz band.

b) The UHF receiver should10 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 shall54 not be degraded by more than 3 dB in the presence of an undesired signal as specified in Table 34 for the relevant receiver type.

Table 34: Receiver Spurious Frequency Rejection Undesired Signal

All spurious response frequencies up to 1 GHz1

All spurious response frequencies up to 1 GHz1

* Continuous Wave

Note 1: Collocation testing will not be conducted where the frequency of the interfering signal is coincidental with a known spurious response frequency.

Receiver Distortion Receiver Intermodulation

a) The sensitivity requirements defined in section 3.2.2.1.2 shall55 not be degraded by more than 3 dB in the presence of two undesired signals as defined in Case A of Table 35, 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 shall56 not be degraded by more than 3 dB in the presence of two undesired signals as defined in Case B of Table 35, 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 shall57 not be degraded by more than 3 dB in the presence of two undesired signals as defined in Case C of Table 35, 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 shall58 not be degraded by more than 3 dB in the presence of two undesired signals as defined in Case D of Table 35, with frequencies chosen such that the 2nd order products are located on the chosen UHF receiver operating frequency.

Table 35: Receiver Intermodulation Undesired Signals

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

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

Receiver Cross Modulation

a) The sensitivity requirements defined in section 3.2.2.1.2 shall59 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 shall60 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 shall61 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.

Receiver Frequency Tolerance

a) The frequency tolerance of the receiver reference frequency shall62 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 shall63 have a tuning adjustment to compensate for aging during the minimum useful service life1 of the equipment.

c) The receiver operating frequency shall64 be adjustable to within 1 ppm of the tuned channel center frequency.

d) If a measurement of the receiver frequency reference is required to align the radio to meet the tolerance defined in 3.2.2.1.7.a, the external reference frequency monitor port shall65 have an impedance of 50 ohms.

e) If a measurement of the receiver frequency reference is required to align the radio to meet the tolerance defined in 3.2.2.1.7.a, the external reference frequency monitor port shall66 have a reference signal level greater than or equal to −20 dBm.

f) If a measurement of the receiver frequency reference is required to align the radio to meet the tolerance defined in 3.2.2.1.7.a, the receiver shall67 provide an output of the reference frequency signal for measurement, testing and alignment.

g) If a measurement of the receiver frequency reference is required to align the radio to meet the tolerance defined in 3.2.2.1.7.a, the reference signal monitor port shall68 be sufficiently isolated such that a short circuit applied from the monitor port to ground does not degrade the radio performance as specified in section 3.2.2.1, Receiver Requirements.

Note 1: The minimum useful service life is defined in section 3.5.3.

Receiver Audio Output Control

a) The remote audio output level of the receiver shall69 be adjustable in the range between −25 dBm (−0/+1 dB) and +10 dBm (−0/+2 dB) in the presence of a standard desired signal.

b) The remote audio output level of the receiver shall70 be adjustable in 0.5 dB steps or less.

c) The remote audio output level of the receiver should11 be adjustable in 0.25 dB steps or less.

d) The receiver shall71 have a control parameter for adjusting the remote audio output level as defined in Table 316.

e) The receiver should12 have a control parameter for adjusting the remote audio output level as defined in Table 318.

f) The local audio output level1 of the receiver shall72 be adjustable in the range between −25 dBm (−0/+1 dB) and +10 dBm (−0/+2 dB) in the presence of a standard desired signal.

g) The local audio output level1 of the receiver should13 be adjustable in 0.5 dB steps or less.

Note 1: Receiver local audio interfaces are defined in section 3.2.2.1.1.

Receiver Audio Level Regulation

a) The remote audio output level of the receiver (adjusted for rated audio output power) shall73 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) shall74 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.

Receiver Audio Automatic Level Stabilization

a) The remote audio output level of the receiver (adjusted for standard audio output power) shall75 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.

Receiver Audio Mute and Attenuation

a) The receiver should14 have a discrete analog input for muting the receiver remote audio output.

b) The receiver mute function should15 have a control parameter to be enabled or disabled as defined in Table 318.

c) The receiver should16 have a control parameter for muting the receiver remote audio output as defined in Table 318.

d) The receiver muting function attenuation level should17 be selectable with the following values: −15 dB, −20 dB, or no audio (i.e., “no audio” is defined as at least 70 dB down from a reference level of +10 dBm).

e) The tolerances for the -15 dB and -20 dB selectable attenuation should18 be ±2 dB.

f) The default for the selectable attenuation should19 be no audio.

g) The receiver should20 have a control parameter for selecting the muting function attenuation level as defined in Table 318.

h) The muting signal should21 have an attack time no greater than 10 ms.

i) The receiver audio should22 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.

j) The receiver should23 provide a confirmation signal via the receiver remote interface for the duration of the mute.

Receiver Average Audio Output

a) The remote audio output level of the receiver (adjusted for standard audio output power using a reference desired signal) shall76 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) shall77 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 samples were made available prior to release of the final Screening Information Request (SIR).

Receiver Audio Distortion

a) The remote audio output shall78 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 shall79 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.

Receiver Audio Frequency Response

a) The remote audio output level shall80 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 shall81 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 36.

c) The remote audio output level shall82 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 36.

d) The remote audio output level shall83 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 36 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 36: Receiver Audio Frequency Response Audio Bands

(Hz)

(Hz)

Receiver Squelch Squelch

a) The…