Mobile Digital Equipment NIJ Standard-0215.01 potx

4.4.2 Humidity Range After the mobile digital device has been maintained at 50 'C 122 'F and 90 percent relative humidity for at least 8 h, its performance shall not vary, with respect

U.S Department 'of Justice

National Institute of Justice

TECHNOLOGY ASSESSMENT PROGRAM

Mobile Digital

ABOUT THE TECHNOLOGY ASSESSMENT PROGRAM The Technology Aseimmt Program b sponsored by the Office of Development, Tuting, and Dissem- ination of the National Institute of Justice (NU), U.S Department of Justice The program responds to the

mandate of the Justice System Improvement Act of 1979, which created NU and directed it to encourage research and development to improve the criminal justice system and to d h c m h a t e the results to Federal, State, and local agencies

The Technology Assessment Program is an applied research effort that determines the technological

needs of justice system agencies, sets minimum performance standards for specific devices, tests commercially available quipment against those standards, and disseminates the standards and the test results to criminal justice a g m c i a nationwide and internationally

The program operates through:

The Technoloay Assessement Progrem Adviwry Cwncfl (TAPAC) consisting of nationally recognized

criminal justice practitioners from Federal, State, and local agencies, which asscses technological needs and

sets priorities for nsearch programs and items to be evaluated and tested

The Low Enforcement Stundam's Lobmtory (LESL) at the National Bureau of Standards, which devel- ops voluntary national performance standards for compliance testing to ensure that individual items of equip- ment are suitable for use by criminal justice agencies The standards are based upon laboratory testing and evaluation of representative samples of each item of quipment to determine the key attributes, develop test methods, and establish minimum performance requirements for each essential attribute In addition to the highly technical standards, LESL also produces user guides that explain in nontechnical terms the capabilities

of available quipment

The Technology Asesment h g m m Informzrion Center (TAPIC), operated by a grantee, which super-

vises a national compliance testing program conducted by independent agencies The standards developed by LESL serve as performance benchmarks against which commercial equipment is measured The facilities, personnel, and testing capabilities of the independent laboratories are evaluated by LESL prior to testing each item of equipment, and LESL helps the Information Center staff review and analyze data Test results are

published in Consumer Product Reports designed to help justice system procurement officials make informed purchasing decisions

Publications issued by the Nationai Institute of Justice, including those of the Technology Assessment Program, are available from the National Criminal Justice Reference Service (NCJRS), which serves as a central information and refmnce source for the Nation's criminal justice community For further informa- tion, or to register with NCJRS, write to the National Institute of Justice, National Criminal Justice Reference Service, Washington DC 2053 1

Juna K Stewart, Director National Institute of Justice

U.S Dcpartrnent of Justice

National Institute of Justice

Mobile Digital Equipment

September 1987

U.S DEPARTMENT OF JUSTICE National Institute of Justice

James K Stewart, Director

ACKNOWLEDGMENTS

Thia stmdard was formulated by the Law Enforcement Standuds Laboratory of the National Bureau of Standards under the

d d o n of Manhail J Tresdo, Program Managa for Communications System, and Lawrence K E l i i n Chid of LESL Technical

sshtance in the preparation of the original standard was provided by John T Furze of Urban Sciences, Inc.; Harold E T aggart, John

L Workman, Robert E Nelson, and Leon F Saulsberry of the NBS Electromagnetic Fields Division; and Thomas 0 Twist of the NBS Heat Division Ramon L Jesch and Arthur E Wainright of the NBS Electromagnetic Fields Division performed the additional measure- ments and provided the technical analysm for this revised standard The preparation of this standard war sponsond by the National Institute of Justice Lester D Shubin, Standads Program Manager The standard has b e m reviewed and approved by the Technology -ent Program Advisory Council

The technical effort to develop this standard was d u c t a l under Interagency Agreement LEAA-J-IMMI-3 Project No 8501

The A s s ' i Attomey G e n d , Offia of Justice Fmgmms coordinates the criminal and juvenile justice activities of the

following program Offices and Bumus: National Institute of Justice, B w u of Justice Statistics Bureau of Justice

Assistance Office of Juvenile Justice and Delinquency'Revmtion, and O R i a for Victims of Crime

FOREWORD

This document, NU Standard-0215.01, Mobile Digital Equipment, is an equipment standard developed

by the Law Enforcement Standards Laboratory of the National Bureau of Standards It is produced as part

of the Technology Assessment Program of the National Institute of Justice (NU) A brief description of the program appears on the inside front cover

This standard is a technical document that specifies performance and other requirements equipment must meet to conform to the.needs of criminal justice agencies for high quality service Purchasers may use the test methods described in this report to deterniine firsthand whether a particular piece of equipment meets the standards, or they may have the tests conducted on their behalf by a qualified testing laboratory Procurement officials may also refer to this standard in their purchasing documents and require that equipment offered for purchase meet the requirements, with compliance guaranteed by the vendor or attested to by an independent laboratory

Because this NU standard is designed as a procurement aid, it is necessarily highly technical For those who seek general guidance about the capabilities of mobile digital equipment, user guides are also published The guides explain in nontechnical language how to select equipment capable of performance required by an agency

NU standards are subjected to continuing review Technical comments and recommended revisions are welcome Please send suggestions to the Program Manager for Standards, National Institute of Justice, U.S Department of Justice, Washington, D C 2053 1

Before citing this or any other NIJ standard in a contract document, users should verify that the most recent edition of the standard is used Write to: Chief, Law Enforcement Standards Laboratory, National Bureau of Standards, Gaithersburg, MD 20899

Lester D Shubin Program Manager for Standards National Institute of Justice

NIJ STANDARD

FOR

MOBILE DIGITAL EQUIPMENT

CONTENTS

Foreword

1 Purpose and Scope

2 Classification 3 Definitions

4 Requirements

4.1 Minimum Performance Requirements 4.2 User Information

4.3 Test Sequence

4.4 Environmental Characteristics

4.5 Message Duration 4.6 Information Throughput

4.7 Error Sensitivity 4.8 FM Transceiver Interface

4.9 Display Readability 4.10 Display Memory Retention

4.11 Keyboard

4.12 Display Capacity

4.13 Error Control

4.14 External Data Interface

5 Test Methods ;'

5.1 Standard Test Conditions

5.2 Test Equipment

5.3 Environmental Tests

5.4 Message Duration Tests

5.5 Information Throughput Tests

5.6 Error Sensitivity Tests

5.7 FM Transceiver Interface Tests

5.8 Display ReadabilityT ests

5.9 Display Memory Retention Test

5.10 Keyboard Inspection

5.1 1 Display Capacity Test

5.12 Error Control Tests

Appendix A-Referenc es

Appendix &Bibliography

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COMMONLY USED SYMBOLS AND ABBREVIATIONS

lm

In log

M

m min

mm mph m/s

N N-m

henry hour high frequency hertz (c/s) inside diameter inch

infrared joule lambert liter pound pound-force pound-force inch lumen

logarithm (natural) logarithm (common) molar

meter minute

millimeter mile per hour meter per second newton

m p h x 1 6 0 9 3 4 4 = W

qt x 0.9463529 = L

nanometer number outside diameter ohm

Page probable error Pages

part per million quart

radian radio frequency relative humidity second

standard deviation section

standing wave radio ultrahigh frequency ultraviolet

volt very high frequency watt

wavelength weight

Temperature: (T-I-32) x 5 / 9 = Tsc Temperature: ( F c x 9/5)+ 32= Fr

NIJ Standard9215.01

NIJ STANDARD

FOR MOBILE DIGITAL EQUIPMENT

1 PURPOSE AND SCOPE

The purpose of this document is to establish performance requirements and methods of test for mobile digital equipment used by law enforcement agencies This standard supersedes NU Standard-0215.00 dated May 1983 and incorporates changes in the requirements for error sensitivity, keyboard and the interface with mobile transceivers This revision was necessitated by the improvements in transmission speeds and informa- tion throughput of the past decade

3.1 Audio Output Power

The audiofrequency power dissipated in a load across the receiver output terminals of an unsquelched receiver having a modulated radio frequency (rf) signal input

3.2 Baud (Bd)

A unit of signaling speed equal to the number of discrete conditions or signal events per second For example, 1 Bd equals 1 bit per second (b/s) in a train of binary signals, one 2-b value per second in a train of signals each of which can assume one of four different states, etc

' N u m h in brackcta refer to the refamca in appendix A

3.3 Buffer

A storage device used to compensate for a difference in rate of flow of information or time of occurrence

of events when transferring data from one device to another

3.4 Carrier Attack Time

The time required, after the camer control switch is activated, for the transmitter to produce 90 percent

of the rated carrier output power

error rate may be used

The amount of usable data received per unit time

3.1 3 ~umlnance (Photometric Brightness)

The luminous intensity of any surface in a given direction per unit of projected area of the surface as

viewed from that direction

3.16 Photometer

An instrument for measuring photometric quantities such as luminance, luminous intensity, luminous

flux, and illumination

3.17 Receiver Attack Time

The time required for a receiver to reach 90 percent of rated audio output power after application of a

3.20 Simple Character Parity

A self-checking code, whereby a single binary digit is appended to a character to make the sum of all the bits either even or odd

3.21 Simple Parity

A self-checking code, whereby a single binary digit is3appended to an array of bits to make the sum of all the bits either even or odd

3.22 System Attack Time

The time required, after the transmitter control switch is activated, to produce 90 percent of a designated amount of audio output power at a system receiver when energized by a modulated rf signal generated by the system transmitter

4 REQUIREMENTS 4.1 Minimum Performance Requirements

The mobile digital equipment shall meet or exceed the requirement for each characteristic as given below and as summarized in table 1

4;2 User Information

A nominal value for audio output power and for each applicable characteristic listed in table 1 shall be included in the information supplied to the purchaser by the mobile digital equipment manufacturer or distributor The supplier shall also furnish the operating data rate of the digital device, the range of temper- atures within which the device is designed to be operated and, if applicable, the printing speed Information

on the total message structure including header, if any, source code, and any channel error detection and/or correction scheme used shall also be provided In addition, the manufacturer shall indicate any special equipment necessary to perform the tests detailed herein, and shall provide the data necessary to enable the

FM transceiver equipment to interface with the digital equipment being tested

TABLE I Minimum performance q u i m n e n t s for mobile digital equipment

Requirrment Perfbmance Chamcteristic

B Message Duration Variance

(supply voltage varied f 10%

(supply voltage varied f 1Wo) I7 dB

F Error Sensitivity (75% error free)

(1 2 dB SINAD Reference)

(supply voltage varied - 20%) 18 dB

G .Audio Output Power M i n g 10%

J Display Readability Variance

(supply voltage varied 2 ~ W O )

K Display Readability Variance

(supply voltage varied -20%)

M Display Brightness Adjustment

N Display Memory Retention

is operated at 60 'C (140 'F') or the highest temperature at which the manufacturer states that the device will

operate properly (sec 4.2), whichever is higher, its performance shall not vary, with respect to the nominal value, more than item R in table 1 for message duration and +2 dB (item S) for error sensitivity

4.4.2 Humidity Range

After the mobile digital device has been maintained at 50 'C (122 'F) and 90 percent relative humidity for

at least 8 h, its performance shall not vary, with respect to the nominal value, more than item T for message duration and k 2 dB (item U) for error sensitivity

4.4.3 Vibration Stability

No fixed part of the mobile digital device shall come loose, nor any movable part be shifted in position

or adjustment, as a result of this test

4.4.4 Shock Stability

No fixed part of the mobile digital device shall come loose, nor any movable part be shifted in position

or adjustment, as a result of this test

4.5 Message Duration

The message duration characteristics of the mobile digital device shall be measured in accordance with section 5.4

4.5.1 Type I Devices

The maximum message duration shall be 1.2 s (item A) including all automatic transmissions needed for

error correction and/or acknowledgment and excluding system attack time When the standard supply voltage is varied + 10 percent and -20 percent, the message duration shall not vary more than 0.05 s (item

B)

4.5.2 Type ll and Ill Devices

The maximum message duration shall be 6.0 s (item A) including all automatic transmissions needed for error correction and/or acknowledgment and excluding system attack time When the standard supply voltage is varied f 10 percent and -20 percent, the message duration shall not vary more than 0.1 s (item B)

4.6.3 Type Ill Devices

The information throughput per error-free transmission shall be at least 30 alphanumeric characters per

a At least 75 percent of the preformatted digital transmissions shall be error free when the rf input to the

receiver is at the 15-dB SINAD level (item D)

When the standard supply voltage is varied + 10 percent, at least 75 percent of the preformatted digital transmissions shall be error free when the rf input to the receiver is at the 17-dB SINAD level (item E) When

the standard supply voltage is reduced by 20 percent, at least 75 percent of the preformatted digital transmis- sions shall be error free when the rf input to the receiver is at the 18-dB SINAD level (item F)

4.7.2 Type ll and Ill Devices

When tested with a transmission consisting of a random sequence of the maximum number of characters that the device under test is capable of transmitting and/or receiving or 250 characters, whichever is smaller,

at least 75 percent of all digital test transmissions shall be error free when the rf input to the receiver is at the 18dB SINAD level (item D)

When the standard supply voltage is varied f 10 percent, at least 75 percent of the digital test transmis- sions shall be error free when the rf input to the receiver is at the 20dB SINAD level (item E) When the standard supply voltage is reduced by 20 percent, at least 75 percent of the digital test transmissions shall be error free when the rf input to the receiver is at the 21dB SINAD level (item F)

4.8 FM Transceiver lnterface

The F M transceiver interface characteristics of the mobile digital device shall be measured in accordance with section 5.7

4.8.1 Audio Output Power Loading

When connected to the mobile digital device, the interfaced receiver shall not have its audio output power decreased more than 10 percent (item G) from its value prior to connection

4.8.2 Audio Distortion Loading

When connected to the mobile digital device, the interfaced receiver shall not have its audio distortion increased more than 6 percent (item H) from its value prior to connection

4.8.3 Digital Data Decode Interface

The error sensitivity requirement (sec 4.7) shall be met with the volume and squelch controls of the FM transceiver in any position

4.8.4 General Interface Considerations

The interface between the mobile digital equipment and the mobile transceiver system shall be made

using a single cable and two connectors If it is necessary to make any interface connections to the transceiver trunk mount, then all transceiver connections shall be made at the trunk mount In addition, the power connections from the digital equipment to the 12-V power source shall be independent of the transceiver

A standard mobile control head and a functional interface between the mobile control head and the mobile transceiver are defined in NU Standard-0216.00 [2] The primary control head connector is a D-series, 25-pin subminiature connector available from several manufacturers.' -If the interface is at the control head, it

is suggested that the mobile digital equipment be connected using a "tee" type connector (fig 1) which is inserted between the male plug and the female receptacle specified in NU Standard-0216.00 [2] A standard jumper shall be provided with the connector to assure continuity when some connections are unused

MICROPHONE HI 1 MICAOPHONE LO 2 SWITCHED BATTERY POSITIVE [A+] 3

BATTERY POSITIVE [A+] 4

IGNITION SWITCH 5

IGN SWITCHED BAT POS [A+] 6

PUSH-TO-TALK 7 VOLUME/SQUUCH LO 8

SQUELCH ARM 9 VOLUME/SQUUCH HI 10

VOLUME ARM 11

F1 12 F2 13

F3 14

F4 15 BATTERY NEGATIVE [A-1 16

4.9.2 Type II and Ill bevices wlth Illumlnatd Displays

Terminal displays which utilize luminous alphanumerics for the visual readout elements shall have a

minimum daylight luminance contrast of 2.5 (item I) When the standard supply voltage is varied +lo

percent, the luminance shall not vary more than 3 percent (item J) When the standard supply voltage is reduced by 20 percent, the luminance shall not vary more than 5 percent (item K)

The luminous display brightness shall be capable of being continuously reduced by a suitable control to

10 percent (item L) of its maximum measured luminance or 6.85 cd/m2 (20 fL) (item M), whichever is smaller

4.10 Display Memory Retention

The display memory retention characteristics of the mobile digital device illuminated display shall be

measured in accordance with section 5.9

Once a digital message has been received and displayed on an illuminated display, all of the message shall

be retained and no extraneous material added in memory when the supply voltage is reduced to 5 V (item N)