**NTIA Report 03-404**![](media/image1.wmf){width="6.502777777777778in"
height="3.251388888888889in"}

**RECEIVER SPECTRUM STANDARDS**

**Phase 1 -- Summary of Research into Existing Standards**

*technical report*

**U.S. DEPARTMENT OF COMMERCE  National Telecommunications and
Information Administration**

**NTIA Report 03-404**

**RECEIVER SPECTRUM STANDARDS**

**Phase 1 - Summary of Research into Existing Standards**

####### **Bernard Joiner**

![](media/image2.jpeg){width="1.7583333333333333in"
height="1.7472222222222222in"}

**U.S. Department of Commerce**

**Donald Evans, Secretary**

Michael D Gallagher, Acting Assistant Secretary

for Communications and Information

####### **NOVEMBER 2003**

TABLE OF CONTENTS

[EXECUTIVE SUMMARY iv](#__RefHeading___Toc50944351)

[GLOSSARY vi](#__RefHeading___Toc50944352)

[Section 1 INTRODUCTION 1](#introduction)

[1.1 Background 1](#number-range-chapterbackground)

[1.2 Objectives 3](#objectives)

[1.3 Approach 3](#approach)

[Section 2 TECHNICAL BACKGROUND 4](#technical-background)

[Section 3 FEDERAL AGENCY STANDARDS 7](#federal-agency-standards)

[3.1 National Telecommunications And Information Administration (NTIA)
7](#national-telecommunications-and-information-administration-ntia)

[3.2 Federal Communications Commission (FCC)
11](#federal-communications-commission-fcc)

[3.3 Department Of Defense (DOD) 12](#department-of-defense-dod)

[3.4 Federal Aviation Administration (FAA)
13](#federal-aviation-administration-faa)

[3.5 Department Of Agriculture 14](#department-of-agriculture)

[Section 4 U.S. INDUSTRY ASSOCIATION STANDARDS
17](#u.s.-industry-association-standards)

[4.1 Telecommunications Industry Association (TIA)
17](#telecommunications-industry-association-tia)

[4.2 Consumer Electronics Association (CEA)
18](#consumer-electronics-association-cea)

[4.3 Radio Technical Commission For Aeronautics (RTCA)
19](#radio-technical-commission-for-aeronautics-rtca)

[4.4 Radio Technical Commission For Maritime Services (RTCM)
24](#radio-technical-commission-for-maritime-services-rtcm)

[Section 5 INTERNATIONAL STANDARDS 26](#international-standards)

[5.1 International Telecommunications Union (ITU)
26](#international-telecommunication-union-itu)

[5.2 International Civil Aviation Organization (ICAO)
28](#international-civil-aviation-organization-icao)

[5.3 European Telecommunication Standard Institute (ETSI)
29](#european-telecommunication-standard-institute-etsi)

[5.4 International Electrotechnical Commission (IEC)
31](#international-electrotechnical-commission-iec)

[5.5 International Maritime Organization (IMO)
33](#international-maritime-organization-imo)

[Section 6 SUMMARY OF FINDINGS 35](#summary-of-findings)

[Section 7 OBSERVATIONS AND RECOMMENDATIONS FOR PHASE 2 STUDY
36](#observations-and-recommendations-for-phase-2-study)

[7.1 Observations 36](#observations)

[7.2 Recommendations for Future Study
39](#recommendations-for-future-study)

[]{#__RefHeading___Toc50944351 .anchor}**EXECUTIVE SUMMARY**

As part of the overall spectrum management process, the National
Telecommunications and Information Administration (NTIA) and the Federal
Communications Commission (FCC) have developed radio regulations to help
ensure that the various radio services operate compatibly in the same
environment without unacceptable levels of radio frequency interference.
These regulations generally focus on sharing spectrum and the
interfering potential of transmitters. Less attention has been given to
the regulation of receiver parameters and the associated non-cochannel
interference issues.

In recent years, there have been a growing number of cases of
non-cochannel interference that has been caused by inadequate
performance of receivers instead of by transmitter performance. One
element in the prevention of non-cochannel interference is the design
and use of quality receivers that are less susceptible to interference.
Receivers are often vulnerable to interference from non-cochannel
signals because of inadequate selectivity. This has resulted in
complaints of interference, sometimes requiring legitimate transmitting
stations to cease or limit their operation even when a poor performing
receiver is mainly at fault. In addition to interference problems, the
lack of receiver standards has hindered efficient management of the
spectrum by putting restraints on adjacent channel assignments in many
areas.

The objective of this task is to undertake a broad review of receiver
spectrum standards to characterize their status and to explore needs and
options for promoting the use of more interference-robust receivers. The
first phase includes the identification of existing standards, both
mandatory and voluntary. This report presents the results of this first
phase. The second phase will examine the underlying requirements, assess
trade-offs among potential regulatory approaches and develop appropriate
recommendations.

With the exception of certain television services, the FCC has not
published receiver spectrum standards and has allowed the marketplace to
determine the appropriate receiver specifications. Realizing that poorly
designed receivers can cause interference and limit the number and type
of transmitters that can operate within a given environment, the FCC is
now considering the adoption of receiver standards. On March 13, 2003,
the FCC adopted a Notice of Inquiry (NOI) to this effect. The NOI
requests, *inter alia*, comments on standards that could be mandatory or
voluntary.

NTIA, on the other hand, has receiver spectrum standards for most
Federal users of the radio spectrum. NTIA has taken the approach that,
for Federal users, the performance of both the transmitter and the
receiver should be regulated. This approach to management of the radio
spectrum emphasizes prevention of interference and improved spectrum
management. Federal agencies generally comply with the NTIA standards,
with some agencies implementing even stricter standards.

Industry associations and standards setting bodies have published
receiver spectrum standards for some radio services. Many manufacturers
adhere to these standards in the interest of providing systems that
perform adequately in adverse operational environments. However, few
standards exist for many non-Federal services and frequency bands.

Many foreign countries have implemented receiver spectrum standards.
Usually, rather than developing standards themselves, they adopt
standards issued by the various international industry and
inter-governmental associations.

The second phase of this study and follow-up work will include an
examination of the need for standards, working with the FCC to establish
standards or other means for preventing non-cochannel interference and
promoting efficient use of the spectrum, updating the Federal standards
in the NTIA manual, and the initiation of a program for greater
promulgating emission characteristics in the Federal bands.

[]{#__RefHeading___Toc50944352 .anchor}**GLOSSARY**

  ---------- ------------------------------------------------------------
  ADF        Automatic Direction Finding

  AGC        Automatic Gain Control

  AM         Amplitude Modulated

  CB         Citizens Band

  CEA        Consumer Electronics Association

  CW         Continuous Wave

  dB         decibels

  dBm        decibels above one milliwatt

  dBW        decibels above one watt

  DME        Distance Measuring Equipment

  DOD        Department of Defense

  EIA        Electronic Industries Association

  EMC        Electromagnetic Capability

  ETSI       Electronic Telecommunications Standards Institute

  FAA        Federal Aviation Administration

  FAR        Federal Aviation Regulation

  FCC        Federal Communications Commission

  FM         Frequency Modulation

  HF         High Frequency (3 to 30 MHz)

  ICAO       International Civil Aviation Organization

  IEC        International Electrotechnical Commission

  IEEE       Institute of Electrical and Electronics Engineers

  ILS        Instrument Landing System

  IM         Intermodulation

  IMO        International Maritime Organization

  ITU        International Telecommunications Union

  kHz        Kilohertz

  kW         Kilowatt

  MF         Medium Frequency (.3 to 3 MHz)

  MHz        Megahertz

  MIL-STD    Military Standard

  NDB        Non-Directional Beacon

  NTIA       National Telecommunications and Information Administration

  PCS        Personal Communications Service

  PM         Phase Modulated

  RTCA       Radio Technical Commission for Aeronautics

  RTCM       Radio Technical Commission for Maritime Services

  SMR        Specialized Mobile Radio

  TIA        Telecommunications Industry Association

  TSO        Technical Standard Order

  UHF        Ultra High Frequency (300 to 3000 MHz)

  VHF        Very High Frequency (30 to 300 MHz)

  VOR        VHF Omni-directional Range

  µvolt      Microvolt

  V/m        Volts per meter
  ---------- ------------------------------------------------------------

#  INTRODUCTION {#introduction .Style-Heading-1-+-14-pt2}

## Number range CHAPTERBackground

As part of the overall spectrum management process, NTIA and the FCC
have developed radio regulations to facilitate operation of various
radio services in the same environment without unacceptable levels of
radio interference. These regulations generally focus on sharing
spectrum and the interfering potential of transmitters. Less attention
has been given to the regulation of receiver parameters and the
associated non-cochannel interference issues.

In recent years, there have been a number of cases of non-cochannel[^1]
interference that have been caused by the inadequate performance of
receivers instead of by transmitter performance. One element in the
prevention of non-cochannel interference and improvement in spectrum
utilization efficiency is the design and use of receivers that are less
susceptible to interference. Some of the reasons why these interference
and efficiency problems are now becoming apparent may include:

> 1\) continued dramatic increase in overall spectrum use;
>
> 2\) mix of analog and digital technologies that have different
> spectral requirements, channel plans and interference suppression
> capabilities;
>
> 3\) introduction of new services and systems without adopting
> standards needed for electromagnetic compatibility with incumbent
> services and systems;
>
> 4\) design tradeoffs favoring inexpensive radio equipment rather than
> good equipment performance;
>
> 5\) reduction or loss of previously available guard bands;
>
> 6\) equipment manufacturers' lack of knowledge of characteristics of
> equipment operating in the same or adjacent bands;
>
> 7\) increased receiver front-end bandwidth associated with greater
> tuning range of certain receivers; and
>
> 8\) different system channel plans in the same band e.g. specialized
> mobile radio (SMR) and public safety operations sharing the 800 MHz
> band.[^2]

Receiver designs that do not take into adequate account the operational
environment are often vulnerable to interference from non-cochannel
signals because of inadequate dynamic range or selectivity within the
Radio Frequency (RF) or Intermediate Frequency (IF) stages of the
receiver. Some examples of interference due to inadequate receiver
design that have been investigated by NTIA include the following:

> 1\) Fixed-satellite service receiving earth stations that use low
> noise preamplifiers at the antenna and have little or no filtering
> prior to active components,[^3]
>
> 2\) Digital radio relay receivers that use low noise preamplifiers and
> have little or no filtering prior to active components,[^4]
>
> 3\) Unlicensed Part 15 receivers, such as garage door openers, that
> use very wide bandwidths,[^5]
>
> 4\) Analog television and other consumer receivers with generally very
> poor RF selectivity,[^6] and
>
> 5\) VHF maritime receivers with insufficient selectivity.[^7]

In the U.S. regulatory environment, it sometimes is not clear whether
interference problems resulting from design faults in the receiver are
the responsibility of the receiver owner or the transmitter owner to
resolve. Without standards, the quality of the receiver and its
interference susceptibility is left to the buyer of a piece of radio
equipment as an aspect of market-place choices. Nevertheless, user
reaction to interference, in some cases public reaction, may place the
onus on changing transmitter operations regardless of the actual cause
of the interference.

The increased demands placed on the radio spectrum require effective
spectrum management. Currently, efficient spectrum utilization is not
achieved due to limitations on the assignment of adjacent or
semi-adjacent channels in the same or nearby areas in some services.
This results in many potential assignments being unavailable. One
well-known example is the practice by the FCC not to assign adjacent
analog television channels in the same area due to poor receiver
selectivity. Had television receiver standards been implemented, this
frequency assignment constraint would not have been necessary and there
would have been adequate television channels to satisfy demand.[^8]

In response to the *Omnibus Budget Reconciliation Act of 1993* and the
*Balanced Budget Act of 1997*, NTIA identified a total of 255 MHz of
Federal spectrum for reallocation to the private sector to provide
additional spectrum for emerging telecommunications technologies and to
help balance the Federal budget through subsequent auction of the
identified bands.[^9] Because of the large spectrum requirements of the
Federal Government and the mandate to avoid excessive costs or serious
degradation to Federal operations, most of these bands were identified
with some degree of encumbrance. These encumbrances include continued
Federal operations within certain bands at specific sites and continued
Federal operations in adjacent bands. Introduction of new services and
systems in the 17 bands identified for reallocation will open up a
significant number of potential adjacent band interference problems. In
the *Spectrum Reallocation Final Report*, NTIA recognized the potential
problems and recommended that effective receiver standards, either
regulatory or established by industry, be developed for new technologies
operating in the reallocated bands adjacent to high-power Federal
systems.[^10]

Domestically, there has been no clear consensus regarding the best means
to assure development and use of suitably designed receivers.
Previously, the FCC declined to mandate standards for commercial
receivers, stating that the pressures of the marketplace provide the
best means to accomplish this goal. In some commercial areas, such as
Personal Communications Service (PCS), system designers have
successfully applied receiver standards. In other areas, especially
where the consumers have access to products that achieve significantly
different levels of performance, the lack of known standards and
compliance may make it difficult for them to make an informed choice.

## Objectives

The objective of Phase 1 of this task was to undertake a broad review of
receiver spectrum standards to characterize their status, both
domestically and internationally. This Report presents the results of
this phase.

Phase 2 will explore various alternatives and options to promote the use
of receivers that are compatible with their operating environment,
especially in commercial bands adjacent to Federal bands in which
Federal high power equipment is operated. That phase will examine
effectiveness trade-offs of various regulatory and voluntary approaches
and develop appropriate recommendations.

## Approach

Existing standards were compiled and reviewed in order to categorize the
various types of standards and associated regulatory frameworks. In the
sections that follow, particularly the tables, concise examples of
different types of receiver standards are provided. For application of a
standard, the complete referenced document should be consulted.[^11]

#  TECHNICAL BACKGROUND {#technical-background .Style-Heading-1-+-14-pt2}

This report focuses on potential non-cochannel interference of an
unwanted transmitter on a victim receiver, and the standards that
recommend receiver design parameters to prevent that interference.

There are two modes whereby an undesired transmitter can interfere with
a non-cochannel receiver. The first mode, usually regulated via limits
on emissions outside the transmitter's authorized bandwidth, involves
unwanted emissions from the transmitter falling in the receiver's tuned
channel. The second mode involves several possible undesired responses
of the receiver to the fundamental emissions in the transmitter's tuned
channel. These modes are generally independent, the former being
dependent on the transmitter's modulation and output filtering, and the
latter on the receiver's selectivity, dynamic range, and intermodulation
rejection capability. It is this second mode that is the subject of this
report.

> These non-cochannel interference mechanisms include:

-   feed through of non-cochannel signals to the demodulator due to
    inadequate selectivity (filtering) at RF and IF stages;

-   blocking due to an undesired very strong signal saturating the first
    amplifier stages and causing severe distortion

-   receiver desensitization resulting from erroneous automatic gain
    control responses to non-cochannel signals;

-   gain compression due to inadequate RF selectivity and dynamic range;

-   spurious responses (to non-cochannel signals that mix with locally\
    generated signals and fall within the receiver passband); and

-   intermodulation of the desired and non-cochannel signals or two or
    more non-cochannel signals in non-linear stages of a receiver (e.g.,
    in connection with gain compression).

The definitions of terms used to specify receiver standards vary among
standardization bodies, especially for technical definitions that
describe the means for measuring compliance. Thus, the source documents
and associated publications, as well as the *IEEE Standard Dictionary of
Electrical and Electronics Terms*, ITU Recommendation SM.332-4,
*Selectivity of Receivers*, and Federal Standard 1037C,
*Telecommunications: Glossary of Telecommunications Terms*, should be
consulted for proper interpretation and application of the standards.
Following are generalized definitions for receiver parameters and other
technical terms used in this report:

-   Adjacent Channel -- A channel with bandwidth equal to, and abutting
    the desired signal channel.

-   Adjacent Channel Rejection (attenuation) -- The ability of a
    receiver to reject signals in the adjacent channel.

-   Adjacent Channel Selectivity -- The ability of a receiver to
    discriminate between a desired signal and an undesired signal in an
    adjacent channel.

-   Blocking -- Saturation of the front end amplifier stage of a
    receiver by an undesired signal on a frequency different from that
    of the desired signal, thereby causing severe distortion and other
    non-linear effects that prevent proper operation of the receiver.
    This is also called the receiver saturation or blanking.

-   Cross Modulation -- The appearance of modulation from an unwanted
    signal on the desired signal.

-   Image Frequency (of a heterodyne receiver) -- The frequency removed
    from the local oscillator frequency, in the direction opposite to
    the direction of the desired signal frequency, by an amount equal to
    the intermediate frequency (i.e., difference between the desired
    channel frequency and the local oscillator frequency).

-   Image Frequency Rejection -- The ability of a receiver to reject
    signals at the image frequency.

-   Intermodulation Rejection -- The ability of a receiver to reject
    intermodulation products produced by the mixing of two or more
    signals at the input to the receiver.

-   Necessary Bandwidth -- For a given class of emission, the width of
    the frequency band which is just sufficient to ensure the
    transmission of information at the rate and with the quality
    required under specified conditions.

-   Non-Cochannel Signal -- Any signal or portion of a signal falling
    outside the authorized bandwidth of the desired signal.

-   Occupied Bandwidth -- The width of a frequency band such that, below
    the lower and above the upper frequency limits, the mean powers
    emitted are each equal to a specified percentage β/2 of the total
    mean power of a given emission. Unless otherwise specified, the
    value of β/2 should be taken as 0.5%. β equals the percentage of
    power outside the occupied bandwidth frequency limits.

-   Out-of-Band Emission -- Emission on a frequency or frequencies
    immediately outside the necessary bandwidth that result from the
    modulation process, but excluding spurious emissions.

-   Selectivity -- Rejection (attenuation) of an undesired signal at
    frequencies close to the desired signal frequency. It is often
    specified as the amount of frequency difference between desired and
    undesired signals needed to produce a specified attenuation of the
    undesired signal.

-   Sensitivity Depression or Desensitization -- The level of a
    non-cochannel signal that increases a receiver signal power
    threshold or decreases receiver gain by a defined amount.

-   Spurious Emission -- Emission on a frequency or frequencies which
    are outside the necessary bandwidth and the level of which may be
    reduced without affecting the corresponding transmission of
    information. Spurious emissions include harmonic emissions,
    parasitic emissions, intermodulation products and frequency
    conversion products, but exclude out-of-band emissions.

-   Spurious Response -- Undesired receiver response resulting from
    mixing of the local oscillator and undesired signals. This includes
    the response to undesired signals at the image frequency.

-   Unwanted Emissions -- Both spurious emissions and out-of-band
    emissions.

#  FEDERAL AGENCY STANDARDS {#federal-agency-standards .Style-Heading-1-+-14-pt2}

## National Telecommunications And Information Administration (NTIA) 

NTIA is responsible for managing Federal Government use of the radio
spectrum. Its regulations, pertaining to Federal Government use of the
frequency spectrum, are contained in the *Manual of Regulations and
Procedures for Federal Radio Frequency Management*.[^12]

The NTIA Manual provides receiver standards for most fixed systems below
15 GHz, most mobile systems below 420 MHz, and most radar systems as
shown in Table 1. Generally, these standards include requirements for
selectivity, spurious response rejection, and intermodulation rejection.
These standards cover a large percentage of the authorized assignments
in the Government Master Frequency File,[^13] including the most
congested Very High Frequency (VHF) and Ultra High Frequency (UHF)
bands.

+------+--------+----------+-------------+---------------------------+
| Tabl |        |          |             |                           |
| e 1. |        |          |             |                           |
| Sum  |        |          |             |                           |
| mary |        |          |             |                           |
| of   |        |          |             |                           |
| NTIA |        |          |             |                           |
| Rece |        |          |             |                           |
| iver |        |          |             |                           |
| S    |        |          |             |                           |
| tand |        |          |             |                           |
| ards |        |          |             |                           |
+======+========+==========+=============+===========================+
| NTIA | Fre    | Service  | Parameter   | Requirement               |
| Ma   | quency |          |             |                           |
| nual | Band   |          |             |                           |
| Sec  |        |          |             |                           |
| tion |        |          |             |                           |
+------+--------+----------+-------------+---------------------------+
| 3    | 1      | VHF      | Selectivity | 90 dB                     |
| .9.7 | 62-174 |          |             |                           |
|      | MHz    | Inter-   |             |                           |
|      |        | national |             |                           |
|      |        |          |             |                           |
|      |        | Boundary |             |                           |
|      |        | and      |             |                           |
|      |        | Water    |             |                           |
|      |        |          |             |                           |
|      |        | Co       |             |                           |
|      |        | mmission |             |                           |
+------+--------+----------+-------------+---------------------------+
|      |        |          | Inte        | 80 dB                     |
|      |        |          | rmodulation |                           |
|      |        |          | Rejection   |                           |
+------+--------+----------+-------------+---------------------------+
|      |        |          | Spurious &  | 100 dB                    |
|      |        |          | Image       |                           |
|      |        |          | Rejection   |                           |
+------+--------+----------+-------------+---------------------------+
| 5    | HF     | Fixed &  | Selectivity | The pass band shall be no |
| .3.1 |        | Mobile   |             | greater than the          |
|      | 3 --   |          |             | authorized bandwidth of   |
|      | 30 MHz |          |             | emission and the slope of |
|      |        |          |             | the selectivity outside   |
|      |        |          |             | the pass band shall be    |
|      |        |          |             | 100 dB/kHz                |
+------+--------+----------+-------------+---------------------------+
| 5    | 4      | Fixed    | Spurious    | The receiver unwanted     |
| .3.3 | 06.1 - |          | Rejection   | signals shall be          |
|      | 420    |          |             | attenuated at least 60 dB |
|      | MHz,   |          |             | relative to the receiver  |
|      | 932    |          |             | sensitivity at the center |
|      | -935/9 |          |             | of the pass band          |
|      | 41-944 |          |             |                           |
|      | MHz,   |          |             |                           |
|      | 1.71 - |          |             |                           |
|      |        |          |             |                           |
|      | 15.35  |          |             |                           |
|      | GHz    |          |             |                           |
+------+--------+----------+-------------+---------------------------+
|      |        |          | Selectivity | The 3 dB receiver         |
|      |        |          |             | bandwidth should be       |
|      |        |          |             | commensurate with the     |
|      |        |          |             | authorized emission       |
|      |        |          |             | bandwidth plus twice the  |
|      |        |          |             | frequency tolerance of    |
|      |        |          |             | the transmitter. The 60   |
|      |        |          |             | dB receiver bandwidth     |
|      |        |          |             | shall not exceed five     |
|      |        |          |             | times the 3 dB receiver   |
|      |        |          |             | bandwidth                 |
+------+--------+----------+-------------+---------------------------+

+------+--------+----------+-------------+---------------------------+
| Tabl |        |          |             |                           |
| e 1. |        |          |             |                           |
| Sum  |        |          |             |                           |
| mary |        |          |             |                           |
| of   |        |          |             |                           |
| NTIA |        |          |             |                           |
| Rece |        |          |             |                           |
| iver |        |          |             |                           |
| S    |        |          |             |                           |
| tand |        |          |             |                           |
| ards |        |          |             |                           |
| (co  |        |          |             |                           |
| ntin |        |          |             |                           |
| ued) |        |          |             |                           |
+======+========+==========+=============+===========================+
| NTIA | Fre    | Service  | Parameter   | Requirement               |
| Ma   | quency |          |             |                           |
| nual | Band   |          |             |                           |
| Sec  |        |          |             |                           |
| tion |        |          |             |                           |
+------+--------+----------+-------------+---------------------------+
| 5.3  | 2      | Fixed &  | Spurious    | All exc. portable: 85 dB  |
| .5.1 | 9.7-50 | Mobile   | Rejection   |                           |
|      | MHz,   |          |             | Portable: 50-60 dB        |
|      | 1      | (Wide    |             | (depending on band)       |
|      | 62-174 | Band)    |             |                           |
|      | MHz,   |          |             |                           |
|      | 406    |          |             |                           |
|      | .1-420 |          |             |                           |
|      | MHz    |          |             |                           |
+------+--------+----------+-------------+---------------------------+
|      |        |          | Adjacent    | All exc. portable: 80 dB  |
|      |        |          | Channel     |                           |
|      |        |          | Rejection   | Portable: 50-70 dB        |
|      |        |          | (Analog)    |                           |
+------+--------+----------+-------------+---------------------------+
|      |        |          | Adjacent    | All exc. portable: 50-55  |
|      |        |          | Channel     | dB                        |
|      |        |          | rejection   |                           |
|      |        |          | (Digital)   | Portable: 50 dB           |
+------+--------+----------+-------------+---------------------------+
|      |        |          | Inte        | All exc. portable: 60-70  |
|      |        |          | rmodulation | dB                        |
|      |        |          | Rejection   |                           |
|      |        |          |             | Portable: 50 dB           |
+------+--------+----------+-------------+---------------------------+
| 5.3  | 138    | Fixed &  | Spurious    | All exc. portable: 70 dB  |
| .5.2 | -150.8 | Mobile   | Rejection   |                           |
|      | MHz,   |          |             | Portable: 60 dB           |
|      | 1      | (Narrow  |             |                           |
|      | 62-174 | Band)    |             |                           |
|      | MHz,   |          |             |                           |
|      | 406    |          |             |                           |
|      | .1-420 |          |             |                           |
|      | MHz    |          |             |                           |
+------+--------+----------+-------------+---------------------------+
|      |        |          | Adjacent    | All exc. portable: 60-70  |
|      |        |          | Channel     | dB                        |
|      |        |          | Rejection   |                           |
|      |        |          |             | Portable: 50-60 dB        |
+------+--------+----------+-------------+---------------------------+
|      |        |          | Inte        | All exc. portable: 70 dB  |
|      |        |          | rmodulation |                           |
|      |        |          | Rejection   | Portable: 50 dB           |
+------+--------+----------+-------------+---------------------------+
| 5    | 2.9-40 | Radars   | Selectivity | The overall receiver      |
| .5.2 | GHz    |          |             | selectivity               |
|      |        | (        |             | characteristics shall be  |
|      |        | Criteria |             | commensurate with or      |
|      |        | B)       |             | narrower than the         |
|      |        |          |             | transmitter bandwidth     |
+------+--------+----------+-------------+---------------------------+
|      |        |          | Spurious    | 50 dB, except where       |
|      |        |          | Rejection,  | broadband front ends are  |
|      |        |          | excluding   | required                  |
|      |        |          | image       |                           |
+------+--------+----------+-------------+---------------------------+
|      |        |          | Stability   | Frequency stability of    |
|      |        |          |             | receivers shall be        |
|      |        |          |             | commensurate with, or     |
|      |        |          |             | better than that of the   |
|      |        |          |             | associated transmitter    |
+------+--------+----------+-------------+---------------------------+
| 5    | All    | Radars   | Selectivity | The overall receiver      |
| .5.3 | Radar  |          |             | selectivity               |
|      | Bands  | (        |             | characteristics shall be  |
|      |        | Criteria |             | commensurate with or      |
|      |        | C)       |             | narrower than the         |
|      |        |          |             | transmitter bandwidth.    |
|      |        |          |             | Receivers shall be        |
|      |        |          |             | capable of switching      |
|      |        |          |             | bandwidth limits to       |
|      |        |          |             | appropriate values        |
|      |        |          |             | whenever the transmitter  |
|      |        |          |             | bandwidth is switched     |
+------+--------+----------+-------------+---------------------------+
|      |        |          | Spurious    | 60 dB                     |
|      |        |          | Rejection,  |                           |
|      |        |          | excluding   |                           |
|      |        |          | image       |                           |
+------+--------+----------+-------------+---------------------------+
|      |        |          | Image       | 50 dB                     |
|      |        |          | rejection   |                           |
+------+--------+----------+-------------+---------------------------+
|      |        |          | Stability   | Frequency stability of    |
|      |        |          |             | receivers shall be        |
|      |        |          |             | commensurate with, or     |
|      |        |          |             | better than that of the   |
|      |        |          |             | associated transmitter    |
+------+--------+----------+-------------+---------------------------+
| 5    | 2      | Radars   | Selectivity | The overall receiver      |
| .5.4 | .7-2.9 |          |             | selectivity               |
|      | GHz    | (        |             | characteristics shall be  |
|      |        | Criteria |             | commensurate with or      |
|      |        | D)       |             | narrower than the         |
|      |        |          |             | transmitter bandwidth.    |
|      |        |          |             | Receivers shall be        |
|      |        |          |             | capable of switching      |
|      |        |          |             | bandwidth limits to       |
|      |        |          |             | appropriate values        |
|      |        |          |             | whenever the transmitter  |
|      |        |          |             | bandwidth is switched     |
+------+--------+----------+-------------+---------------------------+
|      |        |          | Spurious    | 60 dB                     |
|      |        |          | Rejection,  |                           |
|      |        |          | excluding   |                           |
|      |        |          | image       |                           |
+------+--------+----------+-------------+---------------------------+
|      |        |          | Image       | 50 dB                     |
|      |        |          | Rejection   |                           |
+------+--------+----------+-------------+---------------------------+
|      |        |          | Stability   | Frequency stability of    |
|      |        |          |             | receivers shall be        |
|      |        |          |             | commensurate with, or     |
|      |        |          |             | better than that of the   |
|      |        |          |             | associated transmitter    |
+------+--------+----------+-------------+---------------------------+
|      |        |          | Receiver    | Radar systems should have |
|      |        |          | I           | provisions incorporated   |
|      |        |          | nterference | into the system to        |
|      |        |          | Suppression | suppress pulsed           |
|      |        |          | Circuitry   | interference. The         |
|      |        |          |             | following information is  |
|      |        |          |             | intended for use as an    |
|      |        |          |             | aid in the design and     |
|      |        |          |             | development of receiver   |
|      |        |          |             | signal processing         |
|      |        |          |             | circuitry or software to  |
|      |        |          |             | suppress asynchronous     |
|      |        |          |             | pulsed interference. A    |
|      |        |          |             | description of the        |
|      |        |          |             | parametric range of the   |
|      |        |          |             | expected environmental    |
|      |        |          |             | signal characteristics at |
|      |        |          |             | the receiver IF output    |
|      |        |          |             | is:                       |
|      |        |          |             |                           |
|      |        |          |             | Peak I/N ratio:\<50 dB    |
|      |        |          |             |                           |
|      |        |          |             | Pulse width: 0.5 to 4.0   |
|      |        |          |             | μs                        |
|      |        |          |             |                           |
|      |        |          |             | PRF: 100 to 2000 pps      |
+------+--------+----------+-------------+---------------------------+
| 5    | 449    | Radar    | Selectivity | The 3 dB receiver         |
| .5.5 | MHz    |          |             | bandwidth should be       |
|      |        | (        |             | commensurate with the     |
|      |        | Criteria |             | authorized emission       |
|      |        | E, Wind  |             | bandwidth plus twice the  |
|      |        | Profiler |             | transmitter frequency     |
|      |        | Radars)  |             | tolerance of 10 parts per |
|      |        |          |             | million (ppm). The 60 dB  |
|      |        |          |             | receiver bandwidth shall  |
|      |        |          |             | be commensurate with the  |
|      |        |          |             | 60 dB emission bandwidth. |
|      |        |          |             |                           |
|      |        |          |             | Receivers shall be        |
|      |        |          |             | capable of switching      |
|      |        |          |             | bandwidth limits to       |
|      |        |          |             | appropriate values        |
|      |        |          |             | whenever the transmitter  |
|      |        |          |             | bandwidth is switched     |
+------+--------+----------+-------------+---------------------------+
|      |        |          | Spurious    | 60 dB                     |
|      |        |          | rejection,  |                           |
|      |        |          | excluding   |                           |
|      |        |          | image       |                           |
+------+--------+----------+-------------+---------------------------+
|      |        |          | Image       | 50 dB                     |
|      |        |          | Rejection   |                           |
+------+--------+----------+-------------+---------------------------+
|      |        |          | EMC         | Radars shall have the     |
|      |        |          | Provision   | capability to tolerate    |
|      |        |          |             | incoherent pulsed         |
|      |        |          |             | interference of duty      |
|      |        |          |             | cycles less than 1.5      |
|      |        |          |             | percent such that peak    |
|      |        |          |             | interfering signal levels |
|      |        |          |             | 30 dB greater than the    |
|      |        |          |             | receiver noise level at   |
|      |        |          |             | the IF output will not    |
|      |        |          |             | degrade performance       |
+------+--------+----------+-------------+---------------------------+
| 8.   | 1      | Maritime | Adjacent    | 70 dB fixed               |
| 2.29 | 56-162 | Mobile   | Channel     |                           |
|      | MHz    |          | Selectivity | 40 dB portable            |
+------+--------+----------+-------------+---------------------------+
|      |        |          | Spurious    | 85 dB fixed               |
|      |        |          | Rejection   |                           |
|      |        |          |             | 50 dB portable            |
+------+--------+----------+-------------+---------------------------+
| N    |        |          |             |                           |
| ote: |        |          |             |                           |
| This |        |          |             |                           |
| t    |        |          |             |                           |
| able |        |          |             |                           |
| is a |        |          |             |                           |
| sum  |        |          |             |                           |
| mary |        |          |             |                           |
| o    |        |          |             |                           |
| nly. |        |          |             |                           |
| R    |        |          |             |                           |
| efer |        |          |             |                           |
| ence |        |          |             |                           |
| sh   |        |          |             |                           |
| ould |        |          |             |                           |
| be   |        |          |             |                           |
| made |        |          |             |                           |
| to   |        |          |             |                           |
| the  |        |          |             |                           |
| NTIA |        |          |             |                           |
| Ma   |        |          |             |                           |
| nual |        |          |             |                           |
| for  |        |          |             |                           |
| the  |        |          |             |                           |
| full |        |          |             |                           |
| text |        |          |             |                           |
| of   |        |          |             |                           |
| the  |        |          |             |                           |
| s    |        |          |             |                           |
| tand |        |          |             |                           |
| ard. |        |          |             |                           |
+------+--------+----------+-------------+---------------------------+

## Federal Communications Commission (FCC)

The FCC is responsible for regulation of spectrum use by the private
sector and non-Federal agencies. Its regulations are published in Title
47 of the *Code of Federal Regulations*. Generally, the FCC has not
mandated receiver standards in the past. Instead, it has relied on the
market place to encourage manufacturers to design receivers to whatever
specifications are required for market place acceptance. Two exceptions
have been in the area of cable-ready television receivers and unlicensed
devices authorized under FCC Part 15 rules.

The FCC established the Spectrum Policy Task Force to study methods of
improving spectrum management. This Task Force recommended that the FCC
consider adopting receiver spectrum standards. The FCC has recently
released a Notice of Inquiry (NOI) on this subject.[^14]

Part 15.17 of the FCC rules, Radio Frequency Devices, has receiver
standards pertaining to non-licensed devices. It advises parties
responsible for equipment compliance to consider the proximity and the
high power of non-government licensed radio stations, such as broadcast,
amateur, land mobile, and non-geostationary mobile satellite feeder link
earth stations, and U.S. Government radio stations, which could include
high-powered radar systems, when choosing operating frequencies during
the design of their equipment to reduce the susceptibility to receive
harmful interference. Information on non-government use of the spectrum
can be obtained by consulting the Table of Frequency Allocations in the
FCC rules. Information on U.S. Government operations can be obtained by
contacting the Director for Spectrum Plans and Policy within the
National Telecommunications and Information Administration.[^15]

This is an example of an approach to prevent interference, which is
based on the expectation that manufacturers or operators characterize
the electromagnetic environment in which the receiver will operate and
develop appropriate voluntary standards or equipment specifications for
receiver compatibility.

Part 15.118 of the FCC rules on cable ready consumer electronics
equipment gives standards for receivers labeled as cable ready. It
provides very detailed requirements and measurement methods for adjacent
channel interference, image channel interference, direct pickup
interference, and tuner overload.[^16]

In another area, while not setting a standard, the FCC's October 1984
Memorandum Opinion and Order for changes to rules related to educational
FM stations recognized the work of the Electronic Industry
Association/Consumer Electronics Group (EIA/CEG). The FCC acknowledges
that it considers this work essential because insufficient information
is now available to allow the drafting of standards for this service.
The FCC recommends that the EIA Committee fill that void by providing
guidance for improved receivers. The FCC emphasizes this point by
stating that "if the industry, for whatever reasons, is unable or
unwilling to set its own receiver standards, it may be necessary for the
FCC to step in." The Order further states that "the FCC may, upon
review, determine that voluntary compliance by receiver manufacturers
with EIA guidelines is appropriate, and we may be able to begin relaxing
the assignment criteria as market penetration of the improved receivers
expands." [^17] Ultimately, it could also decide to provide interference
protection only to those receivers meeting minimum interference
standards.

## Department Of Defense (DOD)

Receiver standards for the military are published by the U.S. Department
of Defense. They pertain to all procurements by the various military
departments. The primary DOD receiver spectrum standards are contained
in two documents: MIL-STD 461E, *Requirements for the Control of
Electromagnetic Interference Characteristics of Subsystems and
Equipmen*t, and MIL-STD 469B, *Radar Engineering Interface Requirement,
Electromagnetic Compatibility.*

MIL-STD 461E is the primary military standard relating to receiver
spectrum standards.[^18] The provisions of this standard primarily
concern high-level radiation that may cause damage to the receiver, but
Appendix A gives examples of various limits for different conditions for
susceptibility to non-cochannel emissions. It includes a requirement to
provide normal operation with an unwanted signal of 0 dBm outside of the
tuning range of the receiver and also for an unwanted signal of 80 dB
above the desired signal within the tuning range. There is also a cross
modulation requirement for continued operation with a
Carrier-to-Interference power ratio (C/I) of -66 dB. It also includes
limits for bulk cable injection, power line interference, and general
environmental levels. It provides detailed test procedures for measuring
receiver parameters.

The second standard, MIL-STD 469B, contains receiver bandwidth, spurious
responses, and image rejection for various classes of radars.[^19] The
standard and requirements are shown in Table 2. Many of these standards
are derived from the NTIA standards.

Table 2. MIL-STD 469B Requirements for radar receivers

+--------+------+------------------------------------------------------+
| Radar  | Gr   | Requirements                                         |
| c      | oup[ |                                                      |
| ategor | ^21] |                                                      |
| y[^20] |      |                                                      |
+========+======+======================================================+
| 1      | B,   | The overall receiver selectivity characteristics     |
|        | C, D | shall be more narrow than the transmitter bandwidth  |
|        |      | described in tables IV, V, and VI[^22] for the       |
|        |      | respective group. The minimum frequency range over   |
|        |      | which the receiver acceptance bandwidth and          |
|        |      | susceptibility requirements apply shall be the F     |
|        |      | ~MIN~ to F ~MAX~ range in table VI.                  |
+--------+------+------------------------------------------------------+
| 1      | B    | Receiver rejection of spurious responses, other than |
|        |      | image responses, shall be 50 dB or better except     |
|        |      | where broadband front ends are required              |
|        |      | operationally.                                       |
+--------+------+------------------------------------------------------+
| 1      | C, D | Receivers shall be capable of switching bandwidth    |
|        |      | limits to appropriate values whenever the            |
|        |      | transmitter bandwidth is switched (pulse shape       |
|        |      | changed). Receiver image rejection shall be at least |
|        |      | 50 dB; rejection of all other spurious responses     |
|        |      | shall be at least 60 dB.                             |
+--------+------+------------------------------------------------------+
| 2      | B,C  | The required acceptance bandwidth is the receiver    |
|        |      | acceptance bandwidth which includes the fundamental  |
|        |      | frequency response and extends from the lowest to    |
|        |      | the highest frequencies on the selectivity curve     |
|        |      | outside of which all other responses are at least 80 |
|        |      | dB below the fundamental frequency response.         |
|        |      | Required acceptance bandwidths are listed:           |
|        |      |                                                      |
|        |      | Type modulation Required acceptance bandwidth (MHz)  |
|        |      |                                                      |
|        |      | Non-FM pulse 20/t                                    |
|        |      |                                                      |
|        |      | FM pulse 20d/t                                       |
|        |      |                                                      |
|        |      | CW 3 × 10 ^-4^ F~o~                                  |
|        |      |                                                      |
|        |      | FM/CW 3 × 10 ^-4^ F~o~ + B~d~                        |
|        |      |                                                      |
|        |      | The radar receiver shall not exhibit any undesired   |
|        |      | response when subjected to signals outside the       |
|        |      | acceptance bandwidth. RF preselection shall be       |
|        |      | employed except where broadband front ends are       |
|        |      | required operationally. The requirement for          |
|        |      | broadband front ends will be determined by the       |
|        |      | contracting activity and incorporated into the       |
|        |      | equipment or subsystem request-for-proposal,         |
|        |      | specification, contract, or order. The minimum       |
|        |      | frequency range over which the receiver              |
|        |      | susceptibility characteristics apply shall be the F  |
|        |      | ~MIN~ to F ~MAX~ range in table VI for Category 2    |
|        |      | radars.                                              |
+--------+------+------------------------------------------------------+

## Federal Aviation Administration (FAA)

The Federal Aviation Administration is responsible for regulations
pertaining to flight operations. For communications and navigation
equipment, the FAA publishes Technical Standard Orders (TSOs) which
refer to Radio Technical Commission for Aeronautics (RTCA) standards for
their technical requirements.[^23] Some of the TSOs are voluntary, at
least for certain applications, and some are mandatory. For instance, in
order to be identified with the applicable TSO marking, TSO-C32d
prescribes that HF radio receiving equipment must meet the standards set
forth in RTCA Document No. DO-163, *Minimum Performance Standards -
Airborne High Frequency Radio Communications Transmitting and Receiving
Equipment Operating Within the Radio Frequency Range 1.5-30 Megahertz*.
[^24] For their own receivers, the FAA uses procurement specifications
for VHF/UHF AM Air/Ground Radio Communication Receivers. The
specifications are given in Table 3.[^25]

Table 3. FAA VHF/UHF AM Air/Ground Radio Communication Receiver
Specifications

  ----------------------------------- -----------------------------------
  Parameter                           Requirement

  Selectivity, +/- 9 kHz              6 dB

  Selectivity, +/- 25 kHz             60 dB

  Spurious response rejection         70 dB

  Desensitization                     80 dB

  Intermodulation rejection           75 dB

  Cross Modulation rejection (+/- 0.5 70 dB
  MHz)                                

  Cross Modulation rejection (+/- 1.0 75 dB
  MHz)                                

  Cross Modulation rejection (+/- 1.5 80 dB
  MHz)                                
  ----------------------------------- -----------------------------------

## Department Of Agriculture

The Department of Agriculture has requirements given in their *Minimum
Standard Specifications for Analog Only FM Land Mobile Radio
Communications Equipment*.[^26] Test methods and definitions are based
primarily on TIA/EIA--603--A, *Land Mobile FM or PM Communications
Equipment Measurements and Performance Standards* but include additional
limits. These specifications are given in Table 4, Table 5, and Table 6.
[^27] The Department of Agriculture specifications are unique because
they have separate specifications for Economy, Standard, and High
Performance equipment. This concept may also be applicable for the
private sector because it could enable consumers to make purchase
decisions based on required performance and cost.

Table 4. Department of Agriculture VHF Low-Band Receiver Specifications

  ------------------ ------------- -------------- ------------- --------------
  Parameter          Type          Economy        Standard      High
                                                                Perfor-mance

  Adjacent Channel   Portable      70 dB          N/A           75 dB
  Selectivity                                                   

                     Mobile        70 dB          80 dB         85 dB

                     Base          N/A            85 dB         85 dB

  Spurious Rejection Portable      65 dB          N/A           70 dB

                     Mobile        80 dB          80 dB         90 dB

                     Base          N/A            85 dB         100 dB

  Intermod-ulation   Portable      60 dB          N/A           65 dB
  Rejection                                                     

                     Mobile        70 dB          75 dB         75 dB

                     Base          N/A            75 dB         75 dB

  Note: N/A = Not                                               
  Applicable                                                    
  ------------------ ------------- -------------- ------------- --------------

Table 5. Department of Agriculture VHF High-Band Receiver Specifications

  ------------------ ---------- ---------- ----------- -------------- ------------ ----------- --------------
  Parameter          Type       Wideband                              Narrowband               

                                Economy    Stan-dard   High           Economy      Stan-dard   High
                                                       Perfor-mance                            Perfor-mance

  Adjacent Channel   Portable   70 dB      75 dB       75 dB          60 dB        63 dB       65 dB
  Selectivity                                                                                  

                     Mobile     70 dB      80 dB       85 dB          70 dB        70 dB       73 dB

                     Base       85 dB      85 dB       85 dB          78 dB        78 dB       80 dB

                     Aviation   80 dB      N/A         N/A            70 dB        N/A         N/A

  Spurious Rejection Portable   70 dB      70 dB       75 dB          70 dB        70 dB       75 dB

                     Mobile     80 dB      80 dB       90 dB          80 dB        80 dB       80 dB

                     Base       80 dB      85 dB       100 dB         80 dB        85 dB       100 dB

                     Aviation   85 dB      N/A         N/A            80 dB        N/A         N/A

  Intermod-ulation   Portable   65 dB      65 dB       75 dB          65 dB        65 dB       65 dB
  Rejection                                                                                    

                     Mobile     70 dB      75 dB       75 dB          70 dB        70 dB       70 dB

                     Base       75 dB      75 dB       75 dB          70 dB        70 dB       75 dB

                     Aviation   70 dB      N/A         N/A            70 dB        N/A         N/A
  ------------------ ---------- ---------- ----------- -------------- ------------ ----------- --------------

Table 6. Department of Agriculture UHF Receiver Specifications

  ------------------ ---------- ---------- ----------- -------------- ------------ ----------- --------------
  Parameter          Type       Wideband                              Narrowband               

                                Economy    Stan-dard   High           Economy      Stan-dard   High
                                                       Perfor-mance                            Perfor-mance

  Adjacent Channel   Portable   70 dB      N/A         75 dB          60 dB        N/A         65 dB
  Selectivity                                                                                  

                     Mobile     70 dB      80 dB       85 dB          70 dB        70 dB       73 dB

                     Base       75 dB      85 dB       85 dB          75 dB        78 dB       80 dB

                     Aviation   80 dB      N/A         N/A            70 dB        N/A         N/A

  Spurious Rejection Portable   70 dB      N/A         75 dB          70 dB        N/A         75 dB

                     Mobile     80 dB      80 dB       90 dB          80 dB        80 dB       80 dB

                     Base       75 dB      85 dB       100 dB         75 dB        85 dB       100 dB

                     Aviation   85 dB      N/A         N/A            80 dB        N/A         N/A

  Intermod-ulation   Portable   65 dB      N/A         75 dB          65 dB        N/A         65 dB
  Rejection                                                                                    

                     Mobile     70 dB      75 dB       75 dB          70 dB        70 dB       70 dB

                     Base       70 dB      75 dB       75 dB          70 dB        70 dB       75 dB

                     Aviation   70 dB      N/A         N/A            70 dB        N/A         N/A
  ------------------ ---------- ---------- ----------- -------------- ------------ ----------- --------------

#  U.S. INDUSTRY ASSOCIATION STANDARDS {#u.s.-industry-association-standards .Style-Heading-1-+-14-pt2}

## Telecommunications Industry Association (TIA)

The Telecommunications Industry Association, in conjunction with the
Electronic Industries Association (EIA), publishes recommended standards
designed to serve the public interest through eliminating
misunderstandings between manufacturers and purchasers, facilitating
interchangeability and improvement of products, and assisting purchasers
in selecting and obtaining with minimum delay, the proper products for
their particular needs. Adherence to their standards, which is very
widespread, is entirely voluntary. There is close coordination between
TIA and the various international standards organizations. Some examples
from their standards include the following:

TIA/EIA TSB 10-F, *Interference Criteria for Microwave Systems* provides
a methodology and criteria for properly coordinating microwave systems
in merged bands. This bulletin provides guidance and examples for
interference protection and coordination in the microwave bands but it
does not give specific receiver standards.[^28]

TIA /EIA -690, *Recommended Minimum Standards for 800 MHz Cellular
Subscriber Units* provides minimum standards for cellular subscriber
units. It includes the receiver requirements shown Table 7.[^29]

Table 7. TIA-690 Requirements for 800 MHz Cellular Subscriber Units

  ----------------------------------------------------- -----------------
  Parameter                                             Requirement

  Adjacent channel rejection                            16 dB

  Semi-Adjacent channel rejection                       60 dB

  Intermodulation rejection                             55 dB

  Spurious Response Rejection                           60 dB
  ----------------------------------------------------- -----------------

TIA/ EIA--382--A, *Minimum Standards - Citizens Band Radio Service
Amplitude Modulated (AM) Transceivers Operating in the 27 MHz Band*
provides definitions, methods of measurement, and minimum standards for
Citizens Band receivers. This standard includes requirements for
receivers as shown in Table 8.[^30]

Table 8. TIA-382-A Requirements for CB AM Transceivers in the 27 MHz
Band

  ------------------------------------------- ---------------------------
  Parameter                                   Requirement

  Adjacent channel rejection                  35 dB

  Alternate channel rejection                 35 dB

  Receiver desensitization immunity           35 dB

  Spurious response rejection                 30 dB

  Cross Modulation rejection                  25 dB

  Intermodulation rejection                   40 dB

  Impulse Noise Limiter and Blanking          10 dB
  ------------------------------------------- ---------------------------

TIA--603--A, Land *Mobile FM or PM Communications Equipment Measurements
and Performance Standards* provides methods of measurements for
receivers and gives detailed procedures on making measurements of
adjacent channel rejection, offset channel selectivity, spurious
response rejection, intermodulation rejection, and blocking rejection.
This standard is widely referenced in the industry for methods of making
measurements. This standard addresses Class B (standard performance) and
Class A (high interference rejection) equipment as shown in Table 9.
This is similar to the Department of Agriculture requirements for
Economy, Standard, and High Performance equipment.[^31]

Table 9. TIA-603-A Requirements for Land Mobile FM and PM Equipment

  --------- -------------------- ---------------- -------- -------- ----------
  Type      Response             Applicable       Fixed    Mobile   Portable
  Service                        Channelization                     

  Class A   Adj Channel          \>20 kHz         75 dB    75 dB    70 dB
            rejection                                               

  Class B   Adj Channel          \>20 kHz         70 dB    70 dB    60 dB
            rejection                                               

  Class A   Adj Channel          15 kHz           65 dB    65 dB    65 dB
            rejection                                               

  Class B   Adj Channel          15 kHz           60 dB    60 dB    60 dB
            rejection                                               

  Class A   Adj Channel          12.5 kHz         45 dB    45 dB    45 dB
            rejection                                               

  Class B   Adj Channel          12.5 kHz         40 dB    40 dB    40 dB
            rejection                                               

  Class A   Spurious rejection   N/A              75 dB    75 dB    75 dB

  Class B   Spurious rejection   N/A              70 dB    70 dB    60 dB

  Class A   Intermodulation      N/A              75 dB    75 dB    70 dB
            rejection                                               

  Class B   Intermodulation      N/A              70 dB    70 dB    50 dB
            rejection                                               

  All       Offset channel       N/A              20 dB    20 dB    20 dB
            selectivity                                             

  Class A   Blocking Rejection   N/A              90 dB    90 dB    80 dB

  Class B   Blocking Rejection   N/A              80 dB    80 dB    70 dB
  --------- -------------------- ---------------- -------- -------- ----------

## Consumer Electronics Association (CEA)

The CEA, in conjunction with the EIA, publishes standards related to
consumer electronics. It has two standards applicable to receiver
susceptibility: EIA/IS-31, *Recommended Design Guideline, Rejection of
Educational Interference to Channel 6 Television Reception*, and
EIA/IS-16-A, *Immunity of Television Receivers and Video Cassette
Recorders (VCRs) to Direct Radiation From Radio Transmissions, 0.5 to 30
MHz.*

The first standard, EIA/IS-31, establishes design guidelines for color
television receivers and Video Cassette Recorders (VCR's) for providing
rejection of educational and non-commercial Frequency Modulated (FM)
broadcast interference.[^32] It was prepared to permit more educational
FM licenses to be awarded. It provides for three levels of desired
television channel 6 reception with specific FM signals in the
educational FM band of 88.1 to 91.9 MHz. It provides a chart plot of the
undesired to desired signal power ratio that causes a noticeable level
of interference vs. frequency offset of the FM channel from television
channel 6.[^33]

The second standard, EIA/IS-16-A, establishes performance guidelines for
the immunity of television receivers and VCR's to radio transmissions
below 30 MHz and provides recommended measurement procedures. It was
established in response to the large number of complaints by consumers
of interference from amateur radio, citizens band and AM radiobroadcast
stations to television receivers in the early days of television. It
states that an AM broadcast, amateur radio, or Citizens Band (CB) signal
of 1 volt per meter (V/m), or any other emission within the 0.5 to 30
MHz band of 0.3 V/m shall not cause noticeable interference to either
the video or the audio of a television receiver.[^34]

## Radio Technical Commission For Aeronautics (RTCA)

RTCA is an association of aeronautical organizations of the United
States from both government and industry. It is dedicated to the
advancement of aeronautics, seeking sound technical solutions to
problems involving the application of electronics and telecommunications
to aeronautical operations. The association's objective is to resolve
conflicts by mutual agreement of its member organizations. RTCA is not
an official agency of the United States government and its
recommendations may not be regarded as statements of official government
policy unless so enunciated by the government organization or agency
having statutory jurisdiction over any matters to which the
recommendations relate. Many RTCA recommendations are indeed included in
TSO's of the FAA.

RTCA has numerous standards for avionics. Due to the critical nature and
safety of flight issues related to aviation communication and
navigation, RTCA standards are considerably more detailed than most
other standards. Below is a representative sample of RTCA standards
relating to receiver susceptibility to interference.

### **RTCA/DO-143, *Minimum Operating Performance Standards for Airborne Radio Marker Receiving Equipment Operating on 75 MHz*** 

RTCA/DO-143 has requirements for sensitivity depression, cross
modulation, and spurious response for receivers operated in the landing
approach mode. There are also additional requirements for receivers
operated in the enroute mode. As an example, requirements for
sensitivity depression caused by out of band broadcast signals include
requirements that the level of a standard test signal required to
produce receiver threshold shall not increase more than 4 dB when there
is added a channel 4 or 5 television signal having a level of 3.5 volts,
and also that the level of a standard test signal required to produce
receiver threshold shall not increase more than 4 dB when a 0.5 volt FM
RF signal is present between 72.02 to 74.58 MHz and 75.42 to 75.98
MHz.[^35]

### **RTCA/DO-177, *Minimum Operating Performance Standards for Airborne Receiving Equipment for Microwave Landing Systems***

RTCA/DO-177 has non-cochannel interference rejection standards that
require that normal operational specifications shall be met in the
presence of clear wave signals between 5000 MHz and 5250 MHz, at -55
dBW, excluding the band 5030 to 5091.7 MHz. Normal operational
specifications shall also be met with interfering signals between 5250
MHz and 12.4 GHz at -20 dBm. Normal operational specifications shall
also be met in the presence of C-Band weather radars in the 5350 to 5470
MHz band.[^36]

### **RTCA/DO-179, *Minimum Operating Performance Standards for Airborne Radio Direction Finding Equipment*** 

RTCA/DO-179 applies to AM equipment operating in the Medium Frequency
(MF) bands. It gives receiver selectivity requirements to be met in the
presence of RF signal field strengths producing a defined receiver
output at specified frequencies off resonance. Two criteria are given,
one for simply being able to receive the non-directional beacon (NDB)
audio, and the second for a maximum bearing error permitted in the
automatic direction finding (ADF) mode as shown in Table 10. This
standard also contains spurious response rejection requirements for
signals from 50 kHz to 150 MHz as shown in Table 11 and cross modulation
requirements as shown in Table 12.[^37]

Table 10. RTCA DO-179 Selectivity requirements of for ADF Receivers

  ------------------------------- --------------------- -----------------
  Carrier offset frequency        NDB mode              ADF mode

  0 kHz                           0 dB                  NA

  1 kHz                           0 dB                  -10 dB

  1.5 kHz                         6 dB                  -4 dB

  2 kHz                           12 dB                 2 dB

  3 khz                           27 dB                 17 dB

  4 kHz                           42 dB                 32 dB

  5 kHz                           57 dB                 47 dB

  6 kHz                           72 dB                 62 dB

  7 kHz                           \>80 dB               \>70 dB
  ------------------------------- --------------------- -----------------

Table 11. RTCA DO-179 Spurious Response requirements for ADF Receivers

  ---------------------------------------- ------------------------------
  Carrier tuning range                     Response attenuation

  190 -- 850 kHz                           80 dB

  \> 850 kHz                               60 dB
  ---------------------------------------- ------------------------------

Table 12. RTCA DO-179 Cross Modulation Requirements for ADF Receivers

+-----------------+-------------------------+-------------------------+
| Frequency Range | Undesired modulated     | Desired unmodulated     |
|                 | signal                  | signal                  |
|                 |                         |                         |
|                 |                         | (µvolts per meter)      |
+-----------------+-------------------------+-------------------------+
| 50kHz - 550 kHz | 100 µvolts/meter - 0.2  | 100 µvolts/meter - 0.2  |
|                 | volt/meter              | volt/meter              |
+-----------------+-------------------------+-------------------------+
| 550 kHz -- 150  | 100 µvolts/meter - 1    | 100 µvolts/meter - 0.2  |
| MHz             | volt/meter              | volt/meter              |
+-----------------+-------------------------+-------------------------+
| Note: µvolts =  |                         |                         |
| microvolts      |                         |                         |
+-----------------+-------------------------+-------------------------+

### **RTCA/DO-186A, *Minimum Operating Performance Standards for Airborne Radio Communications Equipment operating within the Radio Frequency Range 117.975 to 137 MHz*** 

RTCA/DO186A is an example of a standard that goes into great detail. It
defines six classes of receivers, depending on the channelization and
the capability of offset carrier operation. Some of the specifications
include the following requirements:[^38]

**Skirt Bandwidth (Selectivity)**

Class A receivers utilize a 50 kHz channel separation environment having
offset carrier operation. Class B receivers utilize the same separation
environment but not having offset carrier operation. For these receivers
the requirement is that at a frequency displaced by 43 kHz on either
side of the assigned channel frequency, the level of an input signal
required to produce reference Automatic Gain Control (AGC) voltage shall
be at least 60 dB greater than the level required to produce reference
AGC voltage at the assigned channel frequency.

Class C receivers utilize a 25 kHz channel separation environment having
offset carrier operation. For these receivers the requirement is that at
frequencies displaced by 17 and 25 kHz on either side of the assigned
channel frequency, the input signal level required to produce reference
AGC voltage shall be at least 40 dB and 60 dB respectively, greater than
the level required to produce reference AGC voltage at the assigned
channel frequency.

Class D receivers utilize a 25 kHz channel separation environment not
having offset carrier operation. For these receivers the requirement is
that at a frequency displaced by 22 kHz on either side of the assigned
channel frequency, the input signal level required to produce reference
AGC voltage shall be at least 60 dB greater than the level required to
produce reference AGC voltage at the assigned channel frequency.

Class E receivers utilize a 8.33 kHz channel separation environment not
having offset carrier operation. For these receivers the requirement is
that at a frequency displaced by 7.37 kHz on either side of the assigned
channel frequency, the input signal level required to produce reference
AGC voltage shall be at least 60 dB greater than the level required to
produce reference AGC voltage at the assigned channel frequency.

**Spurious Responses Rejection**

In this standard, spurious response rejection requirements are given for
an input signal level on an undesired frequency that is required to
produce a detector-carrier AGC level equal to that required for a 6 dB
signal-plus-noise to noise ratio on the desired channel. This input
signal shall be not less than 10 millivolts when the undesired input
signal frequency is within 108 to 137 MHz and is on any frequency within
18 kHz of any assignable channel. This requirement does not apply for
input signals on the desired channel and the upper and lower adjacent
channels or when the undesired input signal frequency is between 50 kHz
and 1215 MHz, excluding the band 108 - 137 MHz.

**Cross Modulation Rejection**

With the simultaneous application of an unmodulated carrier at the
desired channel frequency and a signal modulated 30 percent at 1,000 Hz
(undesired signal), the receiver output, due to cross modulation, shall
be at least 10 dB less than rated output. The desired channel signal
shall be at any level between 20 and 500 μvolts, and the interfering
signal (undesired) at a level of 10,000 μvolts at any frequency within
100 - 156 MHz. For Class E receivers, this includes the frequencies
equivalent to the second higher and second lower channels to which the
receiver can be tuned, but excludes the frequency range between these
two channels.

**Intermodulation Rejection**

The standard has an intermodulation requirement for the simultaneous
application of two unmodulated undesired signals within the range of
87.5 to 107.9 MHz, with levels at the receiver input terminals of -5
dBm. With the receiver audio compressor disabled, audio quieting shall
be less than 6 dB.

**Desensitization**

Desensitization is defined for a -87 dBm signal at the receiver input
modulated 30 percent with a 1 kHz tone and at the desired channel
frequency. Under these conditions, the receiver signal-plus-noise to
noise ratio shall not decrease to less than 6 dB in the presence of an
unmodulated carrier having a level of -33 dBm at the receiver input
terminals. This requirement applies at frequencies between 108 and 156
MHz, including the frequencies equivalent to the next higher and the
next lower channels to which the receiver can be tuned, but excluding
the frequency range between these two channels.

Likewise, the signal plus noise to noise ratio shall not decrease to
less than 6 dB in the presence of a modulated carrier having a level of
-7 dBm at the receiver input terminals and at any frequency within the
range 50 kHz through 1215 MHz, except for discrete spurious response
frequencies. These exclude the frequencies within the range 87.5 - 156
MHz. At the discrete spurious response frequencies, the unmodulated
carrier (undesired signal) shall have a level of -33 dBm at the receiver
input terminals. In addition, the signal plus noise to noise ratio shall
not decrease to less than 6 dB in the presence of an unmodulated carrier
having a level of *-5* dBm at the receiver input terminals and at
frequencies between 87.5 and 107.9 MHz.

### **RTCA/DO-189*, Minimum Operating Performance Standards for Airborne Distance Measuring Equipment Operating Within the Radio Frequency Range of 960 to 1215 MHz*** 

RTCA/DO-189 has a recommendation for On and Off Channel Signal
Rejection. It requires that the equipment meet specifications when two
or more Distance Measuring Equipment (DME) ground signals are received
on the same channel if one signal is 8 dB or greater in amplitude than
the next stronger one. This is an example of a cochannel requirement.
RTCA/DO-189 also has requirements for rejecting signals whose receive
pulse pairs deviate more than 2 microseconds from the nominal spacing
for any channels over the input level range from -41 dBm to the
equipment's minimum sensitivity level. For pulse pairs that deviate by
more than 5 microseconds, the requirement is for signals up to -33 dBm.
There are also similar requirements for numerous other combinations of
pulse rates, on and off channel frequency, and pulse pair spacing
requirements. These are other examples of cochannel requirements.
RTCA/DO-189 also has requirements for receiver susceptibility to CW
interference. It requires that the equipment meet certain specifications
when a CW signal having a level of -40 dBm is applied over the input
frequency range of 90 kHz to 10,000 MHz, excluding frequencies within
the 960 to 1215 MHz band.[^39]

### **RTCA/DO-196, *Minimum Operating Performance Standards for VOR Receiving Equipment Operating Within the Radio Frequency Range of 108 to 117.95 MHz*** 

This standard has requirements for adjacent channel rejection, cross
modulation rejection, intermodulation, spurious response, and
desensitization. For adjacent channel rejection it requires that the
bearing information shall not change by more than one degree when a
desired signal is present and any of the following are present in an
adjacent channel:

a\) desired VOR signal of -93 dBm and an undesired first adjacent
channel VOR signal of -113 to -59 dBm,

b\) desired VOR signal between -93 and -53 dBm and an undesired second
adjacent channel VOR signal of up to -33 dBm or 46 dB maximum above the
desired signal,

c\) desired VOR signal of -93 dBm and an undesired first adjacent
channel localizer signal between -113 and -59 dBm, or

d\) desired VOR signal between -93 and -3 dBm and an undesired second
adjacent channel localizer signal up to -33 dBm or 46 dB maximum above
the desired signal.

The standard requires that the bearing information shall not change by
more than one degree when a desired signal is present at -83 to -33 dBm
and an undesired VOR signal is present on any VOR frequency due to cross
modulation. This excludes the first and second adjacent channels, and
also an undesired standard audio test signal between 100 to 108 MHz and
between 118 to 152 MHz at a level of -33 dBm.

The standard provides operating performance requirements for
intermodulation rejection in the presence of commercial FM signals in
the 88 to 108 MHz band.[^40] The standard contains spurious response
rejection requirements for undesired input signals between 50 kHz and
1215 MHz, with additional special requirements applying between 108 and
137 MHz. It requires that the receiver input level of an undesired
signal needed to produce the same AGC level obtained with a -93 dBm
desired signal not be less than -33 dBm. The standard also provides
desensitization requirements for undesired signals up to -13 dBm for any
frequency between 50 kHz and 1215 MHz, with lessened requirements
between 108 to 118.5 MHz.[^41]

### **RTCA/DO-229B, *Minimum Operational Performance Standards for Global Positioning System/Wide Area Augmentation System Airborne Equipment*** 

RTCA/DO-229B provides receiver spectrum requirements for GPS receivers.
Tables and graphs are included that show the interference levels to be
expected as a function of signal type (CW, modulated, or pulse),
frequency, pulse width, and bandwidth for in-band, near-band, and
out-of-band interference.[^42]

## Radio Technical Commission For Maritime Services (RTCM)

The Radio Technical Commission for Maritime Services (RTCM) is an
international non-profit scientific, professional, and educational
organization. RTCM members include both non-government and government
organizations. Although started in 1947 as a U.S. government advisory
committee, RTCM is now an independent organization supported by members
from all over the world. The RTCM attempts to keep members informed
about regional and international maritime radionavigation and
radiocommunication policy issues, regulatory changes, and technical
standards development. It provides a forum in which government and
non-government members can work together to develop technical standards
and consensus recommendations concerning issues of particular concern.
RTCM is actively engaged in the development of international standards
for maritime radionavigation and radiocommunication systems.

RTCM Paper 87-99/SC117-SD*, Recommended Minimum Standards for Installed
Maritime VHF Radiotelephone Equipment Operating in High Level
Electromagnetic Environments* includes measurements made to determine if
the requirements of IEC 1097 are adequate. The paper concludes that
these standards are not adequate for operation in areas of high
electromagnetic interference, and recommends that stricter standards be
developed. The paper itself, however, does not include any new specific
recommendations.[^43]

#  INTERNATIONAL STANDARDS {#international-standards .Style-Heading-1-+-14-pt2}

## International Telecommunication Union (ITU)

The ITU publishes *Radio Regulations* that are ratified to have treaty
status by most of the countries of the world, including the United
States. It also publishes recommendations developed by its
Radiocommunications Sector (ITU-R) that are non-binding, unless they are
incorporated into the Radio Regulations by reference. Most of the *Radio
Regulations* regarding receivers are general in nature. Article 3 of the
*Radio Regulations* provides technical characteristics of equipment.

Paragraph 3.3 of the *Radio Regulations* requires that transmitting and
receiving equipment should be designed to take into account the
technical characteristics of transmitting and receiving equipment likely
to be employed in neighboring and other parts of the spectrum, provided
that all technically and economically justifiable measures have been
taken to reduce the level of unwanted emissions from the latter
transmitting equipment and to reduce the susceptibility to interference
of the latter receiving equipment.

Paragraph 3.12 of the *Radio Regulations* contains a requirement for
receivers. This paragraph requires that receiving stations should use
equipment with technical characteristics appropriate for the class of
emission concerned and selectivity should be appropriate for the
bandwidth of the transmitted signal.

Paragraph 3.13 of the *Radio Regulation* makes a specific point
regarding interference into receivers. This paragraph requires that the
performance characteristics of receivers should be adequate to ensure
that they do not suffer from interference due to transmitters situated
at a reasonable distance and which operate in accordance with these
regulations.[^44]

Recommendation ITU-R M.489-2, *Technical Characteristics of VHF
Radiotelephone Equipment Operating in the Maritime Mobile Service in
Channels Spaced by 25 kHz* contains various requirements for VHF
maritime mobile radios. This recommendation specifies that adjacent
channel rejection and spurious response rejection shall be at least 70
dB and that intermodulation rejection shall be at least 65 dB.[^45]

Recommendation ITU-R IS.1009-1, *Compatibility Between the
Sound-Broadcasting Service in the Band of about 87-108 MHz and the
Aeronautical Services in the Band 108-137 MHz* contains recommendations
for interference suppression of FM broadcast signals by VHF AM
aeronautical receivers. This recommendation specifies criteria for
compatibility between FM broadcast service and aeronautical services. It
identifies four interference mechanisms as follows, and gives criteria
for each.

-   A1 Spurious emissions caused by one or more broadcasting
    transmissions,

-   A2 Out-of-band and similar emissions close to the transmitting
    frequency caused by broadcasting transmissions,

-   B1 Intermodulation generated as a result of a receiver being driven
    into non-linearity by broadcasting signals, and

-   B2 Desensitization caused by one or more broadcasting transmissions.

A protection ratio of the difference between the expected VOR or ILS
receive power and the power received from the broadcasting transmission
is defined for each case. Two categories of receivers are included:
those conforming to the 1985 ICAO Annex 10 standards and those
conforming to the 1992 ICAO Montreal Task Group 12/1 recommendations.
For A1 and A2 interference, the protection ratios for both categories of
receivers are the same and are given in Table 13. For B1 interference,
several formulas are given, depending on the type of intermodulation
product and the category of receivers. These formulas contain a
frequency offset correction term that is also given in Table 13. For B2
interference, formulas are given which include a frequency difference
term.[^46]

Table 13. ITU-R IS.1009-1 Recommendations for VOR/ILS Protection Ratios

  ------------------- -------------- -------------- -------------- --------------
  Frequency           A1             A2             B1             B1
  difference between  Interference   Interference   Interference   Interference
  wanted signal and   Protection     Protection     Correction     Correction
  unwanted signal or  Ratio (dB)     Ratio (dB)     Term (Montreal Term (ICAO
  intermodulation                                   receivers)     ANNEX 10
  product. (kHz)                                                   receivers)

  0                   14             NA             0              0

  50                  7              NA             2              2

  100                 -4             NA             8              5

  150                 -19            -41            16             11

  200                 -38            -50            26             NA

  250                 NA             -59            NA             NA

  300                 NA             -68            NA             NA
  ------------------- -------------- -------------- -------------- --------------

Recommendation ITU-R M.1477, *Technical and Performance Characteristics
of Current and Planned Radionavigation-Satellite Service
(Space-to-Earth) and Aeronautical Radionavigation Service Receivers to
be Considered in Interference Studies in the Band 1559 -- 1610 MHz*
includes chart plots of the maximum expected interference noise levels
to be expected at GPS and similar receivers for interference studies. By
implication, receivers that are not designed to accommodate these levels
of noise may not be able to perform properly.[^47]

Recommendation ITU-R SM.332-4, *Selectivity of Receivers* recommends
that the bandwidth of the receiver shall be no wider than is essential
for the transmission of the necessary modulation of the wanted signal
without significant distortion. It also provides numerous definitions
related to receiver selectivity and spurious response, but does not
provide recommended values.[^48]

## International Civil Aviation Organization (ICAO)

The International Civil Aviation Organization, Volume 1 of Annex 10 to
*The Convention on International Civil Aviation* has several sections on
receiver spectrum standards.[^49] Annex 10 requires that the ILS
receiver design should provide correct operation when an undesired glide
path signal, 150 kHz removed from the desired signal, exceeds the
desired signal by up to 20 dB and when an undesired glide path signal,
300 kHz or further removed from the desired signal exceeds the desired
signal by up to 40 dB.[^50]

Annex 10 also specifies required localizer performance when undesired
signals of 60 dB greater amplitude than the desired signal exist between
90 kHz and 107.8 kHz and also between 112.2 kHz and 1500 MHz. It also
gives glide path receiver response when undesired signals of 60 dB
greater than the desired signal exist between 90 kHz and 329 MHz and
between 335.3 MHz and 1500 MHz.[^51]

In addition, Annex 10 gives criteria for minimum geographic spacing
between ground VOR stations. They are based on criteria for VOR
receivers designed for 50 kHz channel spacing, which include the
following:[^52]

a)  the desired signal exceeds an undesired co-channel signal by 20 dB
    or more;

b)  an undesired signal, 50 kHz removed from the desired signal, exceeds
    the desired signal by up to 34 dB;

c)  an undesired signal, 100 kHz removed from the desired signal,
    exceeds the desired signal by up to 46 dB; and

d)  an undesired signal, 150 kHz or further removed from the desired
    signal, and exceeds the desired signal by up to 50 dB.

Annex 10 also gives interference immunity performance for ILS localizer
receiving systems from VHF FM broadcast signals. Localizer receivers
shall have adequate immunity to interference from two signal third order
intermodulation products resulting from the following:

2N~1~ + N~2~ + 72 \<0 for signals between 107.7 and 108 MHz, and

$\text{2N}\text{1 } + \text{ N}2 + \text{ 3*}(\text{24} - \text{20}\text{log}\left( \frac{\Delta f}{0\text{.}4} \right)) < 0$
for signals below 107.7 MHz,

where N~1~ and N~2~ are the levels in dBm of the two VHF FM signals at
the ILS localizer receiver input.[^53]

This document also states that DME receivers shall reject signals
greater than 900 kHz removed from the desired channel nominal frequency
and having amplitudes up to 42 dB above the threshold sensitivity.[^54]
It also provides minimum performance criteria for DME receivers when an
unwanted signal is on the same frequency as the desired signal and 15 dB
weaker, or plus or minus 2 kHz away and 4 dB weaker, or plus or minus 6
kHz or more away and 55 dB stronger.[^55]

## European Telecommunication Standard Institute (ETSI)

ETSI, the technical standards body under the European Conference of
Postal and Telecommunications Administrations (CEPT), publishes European
Technical Standards which are adopted by most regulatory authorities in
Europe, as well as some non-European countries. Having common standards
facilitates equipment testing and type acceptance in these countries.
Following are excerpts from some of the ETSI standards that relate to
receiver spectrum requirements. In these documents extreme test
conditions have an extended temperature and power supply range compared
to normal conditions.

ETS 300-162, *Electromagnetic compatibility and Radio spectrum Matters
(ERM); Radiotelephone transmitters and receivers for Tuner overload in
the maritime mobile service operating in VHF bands: Technical
characteristics and methods of measurement* specifies the minimum
requirements for shipborne VHF transmitters and receivers capable of
voice and Digital Selective Calling (DSC) fitted with an external
antenna connector for use on board ships. This standard specifies that
radio receivers operating in the maritime mobile VHF band shall meet the
performance standards given in Table 14.[^56]

Table 14. ETS 300 162 Requirements for VHF Maritime Receivers

  ------------------------------ ------------------- --------------------
  Parameter                      Normal Conditions   Extreme Conditions

  Adjacent channel rejection     70 dB               60 dB

  Spurious response rejection    70 dB               NA

  Intermodulation rejection      68 dB               NA

  Blocking level                 \> 90 dBμV          NA
  ------------------------------ ------------------- --------------------

ETS 300 086, *Radio Equipment and Systems Land Mobile Service Technical
characteristics and test conditions for radio equipment with an internal
or external RF connector intended primarily for analogue speech*
contains requirements for land mobile radios in the bands between 30 and
1000 MHz. It includes the requirements given in Table 15.[^57]

Table 15. ETS 300 086 Requirements for Land Mobile Receivers

  ---------------------------------------- ------------- ----------------
  Parameter                                Normal        Extreme
                                           Conditions    Conditions

  Co-channel Rejection for 20 or 25 kHz    0 to -8 dB    0 to -8 dB
  spacing                                                

  Co-channel Rejection for 12.5 kHz        0 to -12 dB   0 to -12 dB
  spacing                                                

  Adjacent channel rejection for 20 or 25  70 dB         60dB
  kHz spacing                                            

  Adjacent channel rejection for 12.5 kHz  60 dB         50 dB
  spacing                                                

  Spurious rejection                       70 dB         70 dB

  Intermodulation rejection, base stations 70 dB         70 dB

  Intermodulation rejection, mobile and    65 dB         65 dB
  portable                                               

  Blocking ratio                           84 dB         84 dB
  ---------------------------------------- ------------- ----------------

ETS 300 133-5, *Electromagnetic compatibility and Radio spectrum Matters
(ERM); Enhanced Radio Message Systems (ERMES); Part 5: Receiver
conformance specification* defines the receiver conformance
specifications for ERMES. This standard includes the requirements for
receivers shown in Table 16.[^58]

Table 16. ETS 300 133-5 Requirements for ERMES Receivers

  -------------------------------- ------------------- ------------------
  Parameter                        Normal conditions   Extreme conditions

  Adjacent channel selectivity     60 dB               50 dB

  Spurious response immunity       76 dBμV/m           NA

  Intermodulation immunity         70 dBμV/m           NA

  Blocking immunity                84 dBμV/m           NA
  -------------------------------- ------------------- ------------------

ETS 300 249, *Satellite Earth Stations (SES); Television Receiver-Only
(TVRO) equipment used in the Broadcasting Satellite Service (BSS)* gives
minimum specifications for the standardization of the technical
characteristics of satellite receiving only earth stations capable of
receiving audio-visual signals and associated data. This standard
recommends that for TVRO equipment the minimum field strength that
produces interference shall not be less than 130 dBμV/m (dB above 1
microvolt per meter) for one type of TVRO receiver, and 125 dBμV/m for
another type.[^59]

ETS 301 390, *Fixed Radio Systems; Point-to--point and
Point-to-Multipoint Systems; Spurious emissions and receiver immunity at
equipment/antenna port of Digital Fixed Radio Systems* defines limits
for receiver immunity for inter-working of digital fixed radio systems.
This document recommends that a clear wave interferer at a level of + 30
dB with respect to the wanted signal shall not result in a BER greater
than 10^-5^ for interfering signals removed by twice the co-polar
channel spacing for point to point systems and five times the co-polar
channel spacing for point to multi-point systems.[^60]

ETS EN 300 698-1 *Electromagnetic compatibility and Radio Spectrum
Matters (ERM); Radio telephone transmitters and receivers for the
maritime mobile service operating in the VHF bands used on inland
waterways; Part 1: Technical characteristics and methods of measurement*
provides the requirements in Table 17 for marine VHF radios.
Measurements are to be made at the antenna terminal. This standard has
an additional requirement from many others in that it provides a
cochannel rejection requirement based on FM capture theory. [^61]

Table 17. ETS EN 300 698-1 Requirements for VHF Maritime Radios

  ------------------------------- ------------------- -------------------
  Parameter                       Normal Conditions   Extreme Conditions

  Cochannel rejection             0 to -10 dB         0 to -10 dB

  Adjacent channel rejection      70 dB               60 dB

  Spurious response rejection     70 dB               70 dB

  Intermodulation rejection       68 dB               68 dB

  Blocking                        90 dBµvolt          90 dBµvolt
  ------------------------------- ------------------- -------------------

## International Electrotechnical Commission (IEC)

The International Electrotechnical Commission (IEC) promotes and
coordinates international standards. These often serve as a basis for
national standardization and as references when drafting international
tenders and contracts. IEC standards are often incorporated into
regulations by reference or adopted in many countries, for instance, by
the members of the European Union through CENELEC (European Committee
for Electrotechnical Standardization). Either the TC 77 or the CISPR
(International Special Committee on Radio Interference) prepare most of
their standards. They work closely with national and regional standards
organizations. In many cases, the IEC adopts standards prepared by other
organizations, especially CENELEC. Likewise, many other standards
organizations adopt the standards of the IEC. In the United States, the
American National Standards Institute (ANSI) has adopted many of the IEC
standards regarding radio frequency matters.

The IEC has both generic and service specific standards. Their generic
standards provide minimum requirements that apply where there are no
service specific standards. They also serve as a minimum guideline for
specific standards, which can generally be no less strict than the
generic standard. Many of the generic standards define the radio
spectrum environment that equipment is expected to operate in. In
describing the environment, the IEC refers to the "totality of
electromagnetic phenomena existing at a given location." Environmental
categories are (1) residential, commercial and light industrial and (2)
industrial. The IEC has several standards that address receiver
parameters, including the following:

IEC Standard 1097-7, *Global Maritime Distress and Safety System
(GMDSS)-Part 7: Ship borne VHF Radiotelephone Transmitter and
Receiver-Operational and Performance Requirements, Methods of Testing
and Required Test Results* is a service specific standard referring to
the VHF maritime service. It provides standards and test methods for
parameters given in Table 18. This standard also requires that the
immunity to interference of the receiver shall be such that the wanted
signal is not seriously affected by unwanted signals.[^62]

Table 18. IEC 1097-7 Requirements for GMDSS Rejection

  ----------------------------------------------------- -----------------
  Parameter                                             Requirement

  Adjacent channel selectivity                          70 dB

  Spurious response rejection                           70 dB

  Intermodulation rejection                             65 dB

  Blocking level                                        90 dBμV/m
  ----------------------------------------------------- -----------------

IEC 1000-2-3, *Electromagnetic Compatibility (EMC) Part 2: Environment
Section 3: Description of the environment -- Radiated and
non-network-frequency-related conducted phenomena* is an example of a
report that characterizes the unwanted signal environment and provides
background information, subjects for consideration and guidelines to
facilitate development of receiver specifications. It provides examples
of electromagnetic fields to be expected in various environments. For
instance, examples of field strengths from authorized transmitters
included in this standard are shown below in Table 19. This report also
has typical values for background noise as well as interfering fields
from power lines and substations, lightning, electrostatic discharge,
and other natural and man-made sources of noise.[^63]

Table 19. IEC 1000-2-3 Requirements -- Interfering Signal Environment

+-----------------------+----------+------------+---------+-----------+
| Service               | F        | ERP        | Typical | C         |
|                       | requency |            | range   | alculated |
|                       | Range    |            | of      | field     |
|                       | (MHz)    |            | sep     | strength  |
|                       |          |            | aration | (V/m)     |
+-----------------------+----------+------------+---------+-----------+
| LF Broadcast and      | 0.014 -- | 2500 kW    | 2-20 km | 5.5-0.55  |
| Maritime              | 0.5      |            |         |           |
+-----------------------+----------+------------+---------+-----------+
| AM Broadcast          | 0.2 --   | 50-800 kW  | 0.5-2   | 12.5-0.78 |
|                       | 1.6      |            | km      |           |
+-----------------------+----------+------------+---------+-----------+
| HF amateur            | 1.8 - 30 | 1 kW       | 10-100  | 22.1-2.21 |
|                       |          |            | m       |           |
+-----------------------+----------+------------+---------+-----------+
| HF communications,    | 1.6 - 30 | 10 kW      | 1-20 km | 0.7-0.04  |
| including SW          |          |            |         |           |
| broadcasting          |          |            |         |           |
+-----------------------+----------+------------+---------+-----------+
| Citizens Band         | 27 - 28  | 12 W       | 10-100  | 2.4-0.24  |
|                       |          |            | m       |           |
+-----------------------+----------+------------+---------+-----------+
| Amateur VHF/UHF       | 50 - 52  | 1-8 kW     | 10-500  | 63-0.44   |
|                       |          |            | m       |           |
|                       | 144 -    |            |         |           |
|                       | 146      |            |         |           |
|                       |          |            |         |           |
|                       | 432 -    |            |         |           |
|                       | 438      |            |         |           |
|                       |          |            |         |           |
|                       | 1290 -   |            |         |           |
|                       | 1300     |            |         |           |
+-----------------------+----------+------------+---------+-----------+
| Fixed and Mobile      | 29 - 40  | 50-130 W   | 2-200 m | 40-0.25   |
| communications        |          |            |         |           |
|                       | 68 - 87  |            |         |           |
|                       |          |            |         |           |
|                       | 146 -    |            |         |           |
|                       | 174      |            |         |           |
|                       |          |            |         |           |
|                       | 422 -    |            |         |           |
|                       | 432      |            |         |           |
|                       |          |            |         |           |
|                       | 438 -    |            |         |           |
|                       | 470      |            |         |           |
|                       |          |            |         |           |
|                       | 860 -    |            |         |           |
|                       | 990      |            |         |           |
+-----------------------+----------+------------+---------+-----------+
| Portable telephones   | 1880 -   | 5 W        | 1-100 m | 15.6-1.56 |
|                       | 1990     |            |         |           |
|                       |          | 1W         | 0.5-10  | 14-0.7    |
|                       |          | (          | m       |           |
|                       |          | DECT)[^64] |         |           |
+-----------------------+----------+------------+---------+-----------+
| VHF TV                | 40 - 68  | 100-320 kW | 0.5-2   | 8-1.11    |
|                       |          |            | km      |           |
|                       | 174 -    |            |         |           |
|                       | 230      |            |         |           |
+-----------------------+----------+------------+---------+-----------+
| FM Broadcast          | 88 - 108 | 100 kW     | 0.25-1  | 8.9-2.2   |
|                       |          |            | km      |           |
+-----------------------+----------+------------+---------+-----------+
| UHF TV                | 470 -    | 500 kW     | 0.5-3   | 10-1.6    |
|                       | 853      |            | km      |           |
+-----------------------+----------+------------+---------+-----------+
| Radar                 | 1000 -   | 1 kW-10 kW | 2-20 km | 350-1.6   |
|                       | 30000    |            |         | (peak)    |
+-----------------------+----------+------------+---------+-----------+
| Note: V/m = Volts per |          |            |         |           |
| meter                 |          |            |         |           |
+-----------------------+----------+------------+---------+-----------+

IEC 1000-2-5, *Electromagnetic compatibility (EMC) Part 2: Environment
-- Section 5: Classification of electromagnetic environments Basic EMC
publication* is another report that characterizes the receiver operating
environment. It defines eight different categories of locations. For
example, it defines location class type 2, typical of a
residential-urban location, and provides a table of expected
electromagnetic fields for various frequency bands and services for CW
and for pulse signals.[^65] The characteristics of a class type 2
location are as follows:

1)  No amateur radio transmitter closer than 20 m

2)  No broadcast transmitter operating below 1.6 MHz closer than 5 km

3)  Possible presence of diathermy therapy equipment

4)  Possible proximity of local substation

5)  Possible proximity of audio/hearing aid systems

IEC 61000-4-3, *Electromagnetic compatibility (EMC) -- Part 4-3: Testing
and measurement techniques-radiated, radio-frequency, electromagnetic
field immunity test* also attempts to characterize the environment. It
provides methods and recommended equipment and facilities for
measurements. It also provides typical transmitter parameters for
various cellular and PCS systems and examples of protection distances
and resulting test levels.[^66]

IEC 61000-6-1, *Electromagnetic compatibility (EMC) -- Part 6: Generic
standards -- Section 1: Immunity for residential, commercial and
light-industrial environments* is an example of a generic standard. It
provides test conditions for immunity to radiated fields and other
sources of interference expected in the environment. One example is for
a receiver to continue to operate normally when subjected to an
electromagnetic field of 3 V/m at frequencies between 80 and 1000 MHz
with 80 percent AM modulation by a 1 kHz tone.[^67]

IEC 61000-6-2, *Electromagnetic compatibility (EMC) -- Part 6-2: Generic
standards -- Section 1: Immunity for industrial environments* is another
generic standard, similar to IEC 61000-6-1, but for industrial
environments. It requires the receiver to continue to operate normally
when subjected to an electromagnetic field of 10 V/m at frequencies
between 80 and 1000 MHz with 80 percent AM modulation by a 1 kHz
tone.[^68]

IEC 60945, *Maritime navigation and radiocommunications equipment and
systems -- General requirements -- Methods of testing and required test
results* is a service specific standard for the maritime services. It
was prepared to provide guidance in performing measurements in
compliance with International Maritime Organization (IMO) resolutions.
It provides test methods and requirements. For example, it states a
requirement that receivers operate without degradation in the presence
of a 10 V/m signal anywhere between 80 MHz and 2 GHz. This standard also
includes a table of radio equipment that should be expected to generate
unwanted signals onboard ships.[^69]

## International Maritime Organization (IMO)

The IMO was established to provide machinery for cooperation among
governments in the field of governmental regulation and practices
relating to technical matters of all kinds affecting shipping engaged in
international trade and to encourage and facilitate the general adoption
of the highest practicable standards in matters concerning maritime
safety, efficiency of navigation and prevention and control of marine
pollution from ships. IEC 60945 was prepared to provide a means for
demonstrating compliance with IMO requirements. For most radio services,
the IMO *General Requirements and Performance standards for Shipborne
Radiocommunications and Navigation Equipment* state that the immunity to
interference of the receiver should be such that the wanted signal is
not seriously affected by unwanted signals.[^70]

#  SUMMARY OF FINDINGS {#summary-of-findings .Style-Heading-1-+-14-pt2}

In this study, NTIA examined the NTIA Manual, the FCC Rules and
Regulations, FCC working group documents, military standards, industry
association standards, and international standards to identify receiver
spectrum standards. Here are NTIA's findings based on the results of
this research.

NTIA includes Federal receiver standards in Chapter 5 of the NTIA Manual
for radar and most non-tactical, fixed and mobile systems, especially
for the more heavily congested bands. These standards apply to a large
percentage of the frequency assignments included in the Government
Master File. Areas where Federal receiver standards are not defined
include: some radionavigation services; especially Criteria A radars
(principally radars having less than 1 kW peak power, radars above 40
GHz, and man-portable radars); portions of the VHF and UHF bands; most
mobile services above 420 MHz; and fixed services above 15.35 GHz.
Federal organizations follow the requirements of the NTIA Manual, but
several, such as the Department of Agriculture and the Department of
Defense, have requirements that are more stringent. The FAA also imposes
the recommendations of the RTCA in many instances.

Generally, the FCC has not mandated conformance with receiver spectrum
standards. However, industry organizations, including TIA, CEA, RTCA,
and RTCM, have set standards for specific services, particularly
television, land mobile and cellular, aeronautical, maritime, and
satellite services. These standards primarily deal with interference
from other signals within the same service, but some directly address
interference from other services. The primary examples of the latter are
aeronautics standards for immunity to interference from VHF television
stations. Unless incorporated in a Federal regulation, such as was done
for certain RTCA standards by the FAA, these standards are voluntary in
the United States.

In the international community, standards are generally developed in a
voluntary framework, but are often incorporated by reference in national
radio regulations in various countries, thereby becoming mandatory. The
IEC, IMO, CEPT, and ETSI have developed standards. In addition to
service specific standards, the IEC has several generic standards as
well as standards that take the approach of defining the receiver
operating environment to enable manufacturers or administrations to
develop their own standards, specifications, or requirements.

#  OBSERVATIONS AND RECOMMENDATIONS FOR PHASE 2 STUDY {#observations-and-recommendations-for-phase-2-study .Style-Heading-1-+-14-pt2}

## Observations

### **Format of Receiver standards**

Most receiver standards developed by NTIA and others are focused on
minimizing susceptibility to non-cochannel interference. These standards
generally limit interference susceptibility to signals outside of the
assigned channel. Most standards can be categorized in one of two
different classes.

The first class describes the "standard" environment(s) in which the
receiver must be designed to operate. Typical parameters are given for
adjacent band signals; high level signals, either in-band or
out-of-band; and signals from other services within the same band.

The second class specifies minimal performance requirements for various
receiver parameters, typically including adjacent channel rejection,
semi-adjacent channel rejection, image frequency rejection, spurious
response rejection, intermodulation response rejection, and blocking
immunity.

For some bands, if the detailed characteristics of the signals that are
likely to cause interference are known, then signal processing or other
methods could be used to provide enhanced protection against that type
of signal. Examples include the requirements relating to interference
between television and FM broadcast services, and between broadcast and
the VHF aeronautical services.

### **Classifications of Receiver standards**

NTIA observed that there were two broad classifications of receiver
minimum performance standards: service specific and generic. Many of the
standards referenced in this report, for instance the TIA standards for
land mobile radios given in section 4.1, are service specific. These
pertain to the requirements and capabilities of receivers operated in a
specific service. The other classification, generic standards, has
several uses. These standards may serve as temporary standards until
service-specific standards are developed, a basis for service specific
standards, or permanent standards for cases where there are no service
specific standards. In an example of a generic standard, as given in
Table 20, two different levels of performance are shown. One would be
high performance receivers designed to operate in areas of high RF
interference, and the other for standard receivers designed to operate
in less demanding environments.

Table 20. Example of a Generic Receiver Spectrum Standard

  ----------------------------- -------------------- ---------------------
  Requirement                   Class A              Class B

  Spurious response rejection   -70 dB               -50 dB

  Adjacent channel rejection    -50 dB               -40 dB

  Semi-Adjacent channel         -80 dB               -60 dB
  rejection                                          

  60 dB Selectivity BW~60~[^71] \< 3\* BW~3~         \< 5\* BW~3~

  Intermodulation rejection     -80 dB               -60 dB

  Image frequency rejection     -70 dB               -50 dB

  Blocking immunity             -70 dB               -50 dB
  ----------------------------- -------------------- ---------------------

The sample standard given in Table 20 is meant to represent various
existing standards included elsewhere in this report. Although the
parameters are representative of what is reasonably achievable, they
could easily be modified without changing the concept of this approach.
Developing measurement methods that are generally applicable to a wide
variety of radio services may pose a challenge.

### **Regulatory Approaches to Promoting or Ensuring Adequate Receiver Performance**

Several regulatory approaches might be followed to prevent non-cochannel
interference. Ultimately, they all will require the close cooperation of
the FCC, NTIA, industry trade groups, service providers, and equipment
manufacturers. They range from maintaining the status quo, to
implementing full mandatory standards for each service across the
spectrum. Responsibility for developing standards could be assumed by
the regulatory agencies, primarily the FCC and NTIA, or entrusted to
user groups. This section presents several alternative approaches. This
list may not be exhaustive and it should be noted that combinations of
several approaches are feasible.

#### Regulatory Mandated Standards

Either the regulatory agencies, industry associations, or both could
develop standards that would become mandatory. The regulatory agencies
could also implement a standard that has already been developed by an
industry association. This is common in certain other countries where
the national regulatory agencies adopt the appropriate standard
developed by an international organization. A domestic example is the
incorporation of RTCA standards by reference in FAA TSO's. If mandatory
standards are adopted, then specific compliance measurement procedures,
certification, and labeling requirements may also have to be mandated.

#### Voluntary Standards

This approach would generally rely on established industry associations
or other bodies to develop standards as well as labeling and compliance
measurement guidelines. These groups could be encouraged to develop
particular standards where appropriate. In some cases, several different
performance levels could be developed. The TIA 603 standard is an
example. Class A and Class B performance levels are shown, depending on
the amount of interference protection required. Another example is the
Department of Agriculture use of different requirements for economy,
standard, and high performance receivers.[^72]

Compliance with voluntary standards could be encouraged by regulations
that explicitly give interference protection to receivers that meet the
voluntary standard. Manufacturers could also be required to include
labeling that identifies with what performance level a receiver
complies. In addition, as the FCC did in its ruling on the EIA
implementing voluntary standards on educational FM stations, the
implication could be that voluntary standards could become mandatory if
sufficient compliance is not obtained.[^73]

#### Reliance on Insightful Manufacturers Specifications and Designs

Rather than setting standards, per se, manufacturers could be encouraged
to design equipment that would perform adequately in the operational
environments. This approach would require the dissemination of
information on the RF environment.

This information could assist equipment manufacturers in designing
equipment that is suitably tolerant of interfering signals operating in
the same or adjacent bands. For instance, the information on currently
authorized and anticipated users in each band could include such
parameters as power levels, emission characteristics, antenna types, and
location. Manufacturers, in the attempt to obtain the widest possible
acceptance of their equipment, generally would be expected to design
their equipment to operate properly in at least the most prevalent
deployment situations. An example of this approach is in the IEC
Standards as shown in Section 5.4 of this Report.

An example of an industry using insightful design to minimize
susceptibility to interference is the case of using coding in garage
door opener and similar receivers. The original openers responded to any
signal in the receive pass band above a threshold. After many cases of
unexpected operation caused by other signals both in band and adjacent
band, most manufacturers started requiring a discrete code to be present
in the receive signal to activate the opener. This provided interference
protection against other signals, both in the same service and in other
services.[^74]

An example of the type of information that can be provided to describe
the signal environment created by one particular service is the Navy's
Cooperative Engagement Capability (CEC) system. This system will operate
in the spectrum below the 4940 to 4990 MHz band that was recently
reallocated to non-Federal use. The parameters in Table 21 were
disseminated to describe the RF environment generated by the CEC system:

Table 21. Navy CEC system

  ----------------------------- -----------------------------------------
  Parameter                     Requirement

  Operating area.               The coordinates of eleven operating
                                areas, generally near military facilities
                                and coastal waters extending 30 nautical
                                miles inland are defined

  Maximum center frequency:     4929 MHz

  Maximum EIRP                  58 dBW

  Out-of-band emissions at +/-  -3 dBc
  7.65 MHz from center          
  frequency                     

  Out of band emissions at +/-  -30 dBc
  12.1 MHz from center          
  frequency                     

  Out of band emissions \> +/-  \<-145 dBc/Hz
  25.6 MHz from center          
  frequency                     

  Harmonics and Spurious        \<-80 dBc
  ----------------------------- -----------------------------------------

To some extent, this is the approach the FCC relies on in Title 47,
Section 15.17, where they state that parties responsible for equipment
compliance are advised to consider other transmitters and to design
receivers to reduce the susceptibility for receiving harmful
interference. This section goes on to state that the FCC Table of
Frequency Allocations and the NTIA should be consulted to determine what
is currently allocated.[^75]

Likewise, section 2.4.4.1 of Annex 10 to the ICAO Convention requires
that a receiver operate properly in the flight environment, although it
does not specifically define the expected environment or indicate where
pertinent information may be obtained.[^76]

## Recommendations for Future Study 

This report presents the results of the first phase of this study, which
is a summary of existing receiver standards. The second phase will
examine several possible approaches to receiver standards, including
those given in Section 7.1.3, above. Based on the findings of this first
phase, it is recommended that this second phase focus on accomplishing
the following tasks.

-   NTIA should participate in the current FCC Notice of Inquiry on
    receiver standards. NTIA will also work with the various Federal
    agencies providing responses to this Phase 1 Report in an attempt to
    develop recommendations that are appropriate for all users.

-   The central question to be answered is for what situations, if any,
    are receiver spectrum standards beneficial. As discussed in Section
    1.1 of this Report, certain studies have indicated that inadequate
    receiver performance in the face of non-cochannel signals has been
    the cause of a number of interference situations. With the increased
    use of the spectrum and the increase in the number of potentially
    incompatible services utilizing the same or adjacent bands, this
    interference will likely get worse if nothing is done to prevent it.
    All significant factors should be assessed, including potential
    improvements in spectrum utilization efficiency and cost impact.

-   If it is found that receiver standards generally provide a net
    benefit, NTIA should work with the FCC and Federal agencies to
    consider generic receiver standards that would apply to a wide
    variety of receiver types and radio services wherever specific
    receiver standards are not available.

-   To further define the need for receiver spectrum standards, NTIA
    should continue studies to identify root causes of receiver
    susceptibility to non-cochannel interference for the various radio
    services based on case studies available by Federal agencies, the
    FCC, industry and consumer groups. Based on identified trends,
    strategies should be developed to mitigate identified problem areas.
    Some examples of areas that need to be further investigated were
    given in Section 1.1 of this Report.

-   NTIA should undertake a thorough review and update to assure that
    Federal receiver standards currently included in Chapter 5 of the
    NTIA Manual are clear, up-to-date, verifiable, necessary, and
    promote the efficient use of the radio spectrum in accordance with
    established policies.

-   NTIA should work with the FCC to consider developing a policy for
    inclusion in the NTIA Manual and the FCC Rules that clearly defines
    receiver protection rights, specifically linking such rights to
    meeting specific and/or generic receiver standards.

-   To ensure that existing or proposed new receiver standards are
    properly applied, further study should be conducted to determine
    whether additional information or regulation is needed to guide
    receiver compliance measurements.

**ENDNOTES**

[^1]: In this report, a non-cochannel interfering signal is any signal
    not falling completely within the authorized bandwidth of the
    desired signal.

[^2]: *Improving Public Safety Communications in the 800 MHz Band,* WT
    Docket No. 02-55, Notice of Proposed Rulemaking, 17 FCCR 4873
    (2002).

[^3]: National Telecommunications and Information Administration,
    *Analysis of Electromagnetic Compatibility Between Radar Stations
    and 4 GHz Fixed-Satellite Earth Stations*, NTIA Report No. 94-313
    (July, 1994); Some receivers in space and microwave applications
    operate in a system with a small link budget, thus presenting
    difficulties with the use of filtering prior to low noise
    amplification.

[^4]: National Telecommunications and Information Administration,
    *Ground-Based Weather Radar Compatibility with Digital Radio-Relay
    Microwave Systems*, NTIA Report No. 90-260 (March 1990).

[^5]: National Telecommunications and Information Administration,
    *Measured Characteristics of Selected Non-Licensed Devices*, NTIA
    TM-91-149 (April 1991); Haley, J, *Navy can't close door jams*,
    Everett Herald (June 5, 1998).

[^6]: *FCC Interference Protection Public Workshop* (August 2, 2002)
    ("Workshop") Transcript (Tr.) at 133.

[^7]: National Telecommunications and Information Administration NTIA
    Report No. 99-362, *Evaluation of Marine VHF Radios: Performance in
    the Savannah, Ga. and New Orleans, La. Port Areas*, National
    Telecommunications and Information Administration (April 1999).

[^8]: Workshop, (Tr.).

[^9]: National Telecommunications and Information Administration,
    *Identification of Alternate Bands, Response to Title III of the
    Balanced budget act of 1997*, NTIA Special Publication 98-39
    (November 1998).

[^10]: National Telecommunications and Information Administration,
    *Spectrum Reallocation Final Report, Response to Title VI -- Omnibus
    Budget Reconciliation Act of 1993*, NTIA Special Publication 95-32,
    at v (February 1995).

[^11]: This report does not contain a complete rendition of the
    standard. In many cases, specific measurement techniques,
    definitions, and applications are provided in the standards but are
    not included here. Comparing standards based on the examples given
    here requires care, as different standards have different
    definitions and measurement requirements for the same parameters.

[^12]: National Telecommunications and Information Administration,
    *Manual of Regulations & Procedures for Federal Radio* *Frequency*
    *Management*, at Chapter 5 (May 2003).

[^13]: The Government Master File is the list of all frequency
    authorizations issued to government agencies. It does not include
    military tactical authorizations.

[^14]: *Interference Immunity Performance Specifications for Radio
    Receivers,* ET Docket No. 03-65, Notice of Inquiry, 18 FCCR 6039
    (2003).

[^15]: 47 C.F.R. Part 15 Subpart A-General at Section 15.17.

[^16]: 47 C.F.R. Part 15 Subpart B-Unintentional Radiators at Section
    15.118.

[^17]: *Changes in the Rules Relating to Noncommercial Educational FM
    Broadcast Stations,* FCC 85-328, Memorandum Opinion and Order*,*
    Docket No. 20735, (released, June 1985).

[^18]: MIL-STD 461E, *Requirements for the Control of Electromagnetic
    Interference Characteristics of Subsystems and Equipment*,
    Department of Defense, at Appendix A (August 1999).

[^19]: MIL-STD 469B, *Radar Engineering Interface Requirement,
    Electromagnetic Compatibility*, Department of Defense (June 1996).

[^20]: Category 1 standards apply to all radars and category 2 to those
    in critical EMC environments.

[^21]: Groups roughly correspond to the criteria listed in NTIA's
    *Manual of Regulations and Procedures for Federal Radio Frequency
    Management* for radars based on frequency, power, and other
    parameters.

[^22]: These tables in MIL-STD-469B provide emission limits for the
    radar transmitters.

[^23]: Section 4.3 of this report.

[^24]: TSO-C32d, *High Frequency (HF) Radio Communication Transmitting
    Equipment Operating Within the Radio Frequency Range of 1.5 to 30
    Megahertz*, Federal Aviation Administration (April 1984).

[^25]: FAA-P-2883, *Purchase Description, VHF/UHF AM Air/Ground Radio
    Communication Receivers*, Federal Aviation Administration, at
    Section 3.2.1.2.1.8 (May 1993).

[^26]: *Minimum Standard Specifications For Analog Only FM Land Mobile
    Radio Communications Equipment*, Department Of Agriculture, Forest
    Service, at Sections 13.1 and 13.2 (2002).

[^27]: TIA/ EIA-603-A, *Land Mobile FM or PM Communications Equipment
    Measurements and Performance Standards*, Telecommunications Industry
    Association, at Sections 2.1 and 3.1 (August 2001)
    ("TIA/EIA-603-A").

[^28]: TIA/EIA TSB 10-F, *Interference Criteria for Microwave Systems*,
    Telecommunications Industry Association (June 1994).

[^29]: TIA/ EIA-690, *Recommended Minimum Standards for 800 MHz Cellular
    Subscriber Units,* Telecommunications Industry Association, at
    Section 2.3 (November 2000).

[^30]: TIA /EIA--382--A *, Minimum Standards - Citizens Band Radio
    Service Amplitude Modulated (AM) Transceivers Operating in the 27
    MHz Band*, Telecommunications Industry Association, at Section 6
    (October 1990).

[^31]: TIA/EIA-603-A at Sections 2.1 and 3.1.

[^32]: EIA/IS-31, *Recommended Design Guideline, Rejection of
    Educational Interference to Channel 6 Television Reception*,
    Electronic Industries Association (July 1987).

[^33]: This is the standard discussed in the FCC October 1984 Order in
    Docket No. 20735, discussed in Section 3.2 of this report.

[^34]: EIA/IS-16-A, *Immunity of Television Receivers and Video Cassette
    Recorders (VCRs) to Direct Radiation From Radio Transmissions, 0.5
    to 30 MHz*, Electronic Industries Association (May 1987).

[^35]: DO-143, *Minimum Operating Performance Standards for Airborne
    Radio Marker Receiving Equipment Operating on 75 MHz*, RTCA, at
    Sections 2-10, 2-13, 2-14 (January 1970).

[^36]: DO-177, *Minimum Operating Performance Standards for Airborne
    Receiving Equipment for Microwave Landing Systems*, RTCA (1981).

[^37]: DO-179, *Minimum Operating Performance Standards for Airborne
    Radio Direction Finding Equipment*, RTCA (May 1982).

[^38]: DO-186A, *Minimum Operating Performance Standards for Airborne
    Radio Communications Equipment Operating Within the Radio Frequency
    Range 117.975 to 137 MHz*, RTCA (October 1995).

[^39]: DO-189, *Minimum Operating Performance Standards for Airborne
    Distance Measuring Equipment Operating Within the Radio Frequency
    Range of 960 to 1215 MHz*, RTCA, at Sections 2.10 and 2.11
    (September 1985).

[^40]: These requirements are the same as those provided in Annex 10 to
    the ICAO convention given in Section 5.2 of this report.

[^41]: DO-196, *Minimum Operating Performance Standards for VOR
    Receiving Equipment Operating Within the Radio Frequency Range of
    108 to 117.95 MHz*, RTCA, at Sections 2.2.2, 2.2.7, and 2.2.8 (March
    1986).

[^42]: DO-229B, *Minimum Operational Performance Standards for Global
    Positioning System/Wide Area Augmentation System Airborne
    Equipment*, RTCA, at Appendix C (October 1999).

[^43]: Paper 87-99/SC117-STD, *Recommended Standards for Installed
    Maritime VHF Radiotelephone Equipment Operating in High Level
    Electromagnetic Environments***,** Version 1.0, Radio Technical
    Commission for Maritime Services (1999).

[^44]: *Radio Regulations*, Article 3 (2001).

[^45]: Recommendation ITU-R M.489-2, *Technical Characteristics of VHF
    Radiotelephone Equipment Operating in the Maritime Mobile Service in
    Channels Spaced by 25 kHz*, at Section 8.4.1 (1995).

[^46]: Recommendation ITU-R IS.1009-1, *Compatibility Between the
    Sound-Broadcasting Service in the Band of about 87-108 MHz and the
    Aeronautical Services in the Band 108-137 MHz* (1995).

[^47]: Recommendation ITU-R M.1477, *Technical and Performance
    Characteristics of Current and Planned Radionavigation-Satellite
    Service (Space-to-Earth) and Aeronautical Radionavigation Service
    Receivers to be Considered in Interference Studies in the Band 1559
    -- 1610 MHz* (2000).

[^48]: Recommendation ITU-R SM.332-4, *Selectivity of Receivers* (1978).

[^49]: *Convention on International Civil Aviation,* International Civil
    Aviation Organization, Annex 10 (1985 and other dates).

[^50]: *Id.* at Section 2.2.16.

[^51]: *Id.* at Section 2.2.18.

[^52]: *Id.* at Section 2.4.6.

[^53]: *Id.* at Section 3.1.4.

[^54]: *Id.* at Section 3.5.5.3.4.

[^55]: *Id.* at Section 3.9.1.1.

[^56]: ETS 300 162, *Electromagnetic compatibility and Radio spectrum
    Matters (ERM); Radiotelephone transmitters and receivers for the
    maritime mobile service operating in VHF bands: Technical
    characteristics and methods of measurement*, European
    Telecommunication Standards Institute (March 1998).

[^57]: ETS 300 086, *Radio Equipment and Systems; Land mobile service;
    Technical characteristics and test conditions for radio equipment
    with an internal or external RF connector intended primarily for
    analogue speech*, European Telecommunication Standards Institute
    (1997).

[^58]: ETS 300 133-5, *Electromagnetic compatibility and Radio spectrum
    Matters (ERM); Enhanced Radio Message Systems (ERMES),* European
    Telecommunication Standards Institute, at Part 5. (1997)

[^59]: ETS 300 249, *Satellite Earth Stations (SES); Television
    Receiver-Only (TVRO) equipment used in the Broadcasting Satellite
    Service (BSS),* European Telecommunication Standards Institute
    (1993).

[^60]: ETS 301 390, *Fixed Radio Systems; Point-to--Point and
    Point-to-Multipoint Systems; Spurious emissions and receiver
    immunity at equipment/antenna port of Digital Fixed Radio Systems*,
    European Telecommunication Standards Institute (2000).

[^61]: ETS 301 698-1, *Electromagnetic compatibility and Radio spectrum
    Matters (ERM); Radio telephone transmitters and receivers for the
    maritime mobile service operating in the VHF bands used on inland
    waterways; Part 1: Technical characteristics and methods of
    measurement,* European Telecommunication Standards Institute (
    2000).

[^62]: Standard 1097-7, G*lobal maritime distress and safety system
    (GMDSS)-Part 7: Shipborne VHF radiotelephone transmitter and
    receiver-Operational and performance requirements, methods of
    testing and required test results*, International Electrotechnical
    Commission, at Sections 4.4 and 5.5.8.3 (1999).

[^63]: Technical Report 1000-2-3, *Electromagnetic compatibility (EMC)
    Part 2: Environment Section 3: Description of the environment,
    Radiated and non-network-frequency-related conducted phenomena,*
    International Electrotechnical Commission (1992).

[^64]: Digital Enhanced Cordless Telecommunications (DECT) is a low cost
    cellular telecommunications system widely used in Europe.

[^65]: Technical Report 1000-2-5, *Electromagnetic compatibility (EMC)
    Part 2: Environment Section 5: Classification of electromagnetic
    environments-Basic EMC publication,* International Electrotechnical
    Commission (1995).

[^66]: Standard 61000-4-3, *Electromagnetic compatibility (EMC) Part
    4-3: Testing and measurement techniques -- radiated,
    radio-frequency, electromagnetic field immunity test,* International
    Electrotechnical Commission (2002).

[^67]: Standard 61000-6-1, *Electromagnetic compatibility (EMC) Part 6:
    Generic standards -- Section 1: Immunity for residential, commercial
    and light-industrial environments,* International Electrotechnical
    Commission (1997).

[^68]: Standard 61000-6-2, *Electromagnetic compatibility (EMC) Part
    6-2: Generic standards - Immunity for industrial environments,*
    International Electrotechnical Commission (1999).

[^69]: Standard 60945, *Maritime navigation and radiocommunication
    equipment and systems -- General requirements -- Methods of testing
    and required test results,* International Electrotechnical
    Commission (2002).

[^70]: *General Requirements and Performance Standards for Shipborne
    Radiocommunications and Navigation Equipment*, International
    Maritime Organization, at Section III/1.1(a)/8, paragraph 8.3
    (2002).

[^71]: BW~60~ and BW~3~ refer to the 60 dB and 3 dB bandwidths
    respectively.

[^72]: Section 3.4 of this report.

[^73]: Section 3.2 of this report.

[^74]: U.S. Department of Commerce/Office of Telecommunications, *An
    Analysis of Remote Control and Security Devices in the 225-400 MHz
    Band*, OT Technical Memorandum 77-244 (November 1977).

[^75]: Section 3.2 of this report.

[^76]: Section 5.5 of this report.