ETSI TS 103 236 V1.1.1 (2014-01)

Electromagnetic compatibility and Radio spectrum Matters (ERM); Continuous Tone Controlled Signalling System (CTCSS) and Digitally Coded Squelch Signalling (DCSS) system

DTS/ERM-TGDMR-317

General Information

• Status: Published
• Publication Date: 16-Jan-2014
• Technical Committee: ERM TGDMR - Digital Mobile Radio
• Current Stage: 12 - Completion
• Due Date: 20-Jan-2014
• Completion Date: 17-Jan-2014

Standards Content (Sample)

ETSI TS 103 236 V1.1.1 (2014-01)






Technical Specification
Electromagnetic compatibility
and Radio spectrum Matters (ERM);
Continuous Tone Controlled Signalling System (CTCSS) and
Digitally Coded Squelch Signalling (DCSS) system

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2 ETSI TS 103 236 V1.1.1 (2014-01)



Reference
DTS/ERM-TGDMR-317
Keywords
air interface, digital, PMR, protocol, radio
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3 ETSI TS 103 236 V1.1.1 (2014-01)
Contents
Intellectual Property Rights . 5
Foreword . 5
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 6
3 Definitions, symbols and abbreviations . 7
3.1 Definitions . 7
3.2 Symbols . 7
3.3 Abbreviations . 7
4 Overview . . 7
4.1 CTCSS . 7
4.2 DCS . 8
4.2.1 DCS codewords . 8
4.2.2 DCS codewords . 8
4.2.3 DCS Modulation . 9
5 Test conditions, power sources and ambient temperatures . 9
5.1 Normal and extreme test conditions . 9
5.2 Test power source . 10
5.3 Normal test conditions . 10
5.3.1 Normal temperature and humidity . 10
5.3.2 Normal test power source . 10
5.3.2.1 Mains voltage . 10
5.3.2.2 Regulated lead-acid battery power sources used on vehicles . 10
5.3.2.3 Other power sources . 10
5.4 Extreme test conditions . 11
5.4.1 Extreme temperatures . 11
5.4.2 Extreme test source voltages . 11
5.4.2.1 Mains voltage . 11
5.4.2.2 Regulated lead-acid battery power sources used on vehicles . 11
5.4.2.3 Power sources using other types of batteries . 11
5.4.2.4 Other power sources . 11
5.5 Procedure for tests at extreme temperatures . 12
5.5.1 Procedure for equipment designed for continuous transmission. 12
5.5.2 Procedure for equipment designed for intermittent transmission . 12
5.6 Test signals . 12
5.7 CTCSS/DCS Signal Generator . 13
5.8 CTCSS/DCS test frequencies/codes . 13
6 Technical Characteristics . 13
6.1 CTCSS Encoder frequency. 13
6.1.1 Definition . 13
6.1.2 Method of measurement . 13
6.1.3 Limits . 13
6.2 Encoder Modulation . 14
6.2.1 Definition . 14
6.2.2 Method of measurement . 14
6.2.3 Limits . 14
6.3 DCS encoder data rate . 14
6.3.1 Definition . 14
6.3.2 Method of measurement . 14
6.3.3 Limits . 14
6.4 Tone signalling squelch threshold . 15
6.4.1 Definition . 15
ETSI

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4 ETSI TS 103 236 V1.1.1 (2014-01)
6.4.2 Method of Measurement . 15
6.4.3 Limits . 15
6.5 Tone signalling false response rate . 15
6.5.1 Definition . 15
6.5.2 Method of Measurement . 15
6.5.3 Limits . 16
6.6 CTCSS code frequency selectivity . 16
6.6.1 Definition . 16
6.6.2 The Method of Measurement . 16
6.6.3 Limits . 16
6.7 Decoder response time . 16
6.7.1 Definition . 16
6.7.2 The Method of Measurement . 17
6.7.3 Limits . 17
6.8 Maximum permissible frequency deviation . 17
6.8.1 Definition . 17
6.8.2 Method of measurement . 18
6.8.3 Limits . 18
6.9 DCS Waveform Distortion . 19
6.9.1 Definition . 19
6.9.2 Method of Measurement . 19
6.9.3 Limits . 20
History . 21

ETSI

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5 ETSI TS 103 236 V1.1.1 (2014-01)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://ipr.etsi.org).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Specification (TS) has been produced by ETSI Technical Committee Electromagnetic compatibility and
Radio spectrum Matters (ERM).
ETSI

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6 ETSI TS 103 236 V1.1.1 (2014-01)
1 Scope
The present document contains technical requirements for Continuous Tone Controlled Signalling System (CTCSS) and
Digitally Coded Squelch Signalling (DCSS).
CTCSS and DCSS systems allow the audio in a receiver to be selectively enabled/disabled on receipt of a specific
tone/code. These tones/codes are transmitted continuously during the transmission so the receiver would normally
implement suitable process to remove them from the wanted audio signal.
The present document specifies signalling systems that may be used with analogue FM voice equipment complying
with either EN 300 086-1 [i.1]/EN 300 086-2 [i.2] or EN 300 296-1 [i.3]/EN 300 296-2 [i.4].
The present document only applies to equipment that employs frequency or phase modulation.
The scope of the present document is similar to prior national standards [i.5], [i.6] and aspects of international standards
[i.7].
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
reference document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
2.1 Normative references
The following referenced documents are necessary for the application of the present document.
None.
2.2 Informative references
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] ETSI EN 300 086-1: "Electromagnetic compatibility and Radio spectrum Matters (ERM); Land
Mobile Service; Radio equipment with an internal or external RF connector intended primarily for
analogue speech; Part 1: Technical characteristics and methods of measurement".
[i.2] ETSI EN 300 086-2: "Electromagnetic compatibility and Radio spectrum Matters (ERM); Land
Mobile Service; Radio equipment with an internal or external RF connector intended primarily for
analogue speech; Part 2: Harmonized EN covering the essential requirements of article 3.2 of the
R&TTE Directive ".
[i.3] ETSI EN 300 296-1: "Electromagnetic compatibility and Radio spectrum Matters (ERM); Land
Mobile Service; Radio equipment using integral antennas intended primarily for analogue speech;
Part 1: Technical characteristics and methods of measurement".
[i.4] ETSI EN 300 296-2: "Electromagnetic compatibility and Radio spectrum Matters (ERM); Land
Mobile Service; Radio equipment using integral antennas intended primarily for analogue speech;
Part 2: Harmonized EN covering the essential requirements of article 3.2 of the R&TTE
Directive".
ETSI

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7 ETSI TS 103 236 V1.1.1 (2014-01)
[i.5] MPT1306: "Continuous tone controlled signalling system (CTCSS) for use in the Land Modile
Services", October 1996.
[i.6] MPT1381: "Digitally Coded Squelch Signalling (DCSS) system for use in the Land Mobile
Services", November 1996.
[i.7] TIA-603-D: "Land Mobile FM or PM communications equipment measurement and performance
standards".
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
Radio Frequency channel: radio frequency carrier (RF carrier)
SINAD Meter: measurement instrument used to measure SND/ND using a band-stop filter
Squelch: circuits or functionality provided that mutes the received signal (audio) under specified conditions, e.g. the
absence of a wanted signal at the input of the receiver
3.2 Symbols
For the purposes of the present document, the following symbols apply:
f lowest modulation frequency
1
f highest modulation frequency
2
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
CTCSS Continuous Tone Controlled Signalling System
DC Direct Current
DCS Digitally Coded Squelch
DCSS Digitally Coded Squelch Signalling
DUT Device Under Test
FM Frequency Modulation
FSK Frequency Shift Keying
LSB Least Significant Bit
MPFD Maximum Permissible Frequency Deviation
MSB Most Significant Bit
NRZ Non Return to Zero
RF Radio Frequency
SINAD Received signal quality based on (Signal + Noise + Distortion)/(Noise + Distortion)
4 Overview
4.1 CTCSS
CTCSS is a system in which the radio equipment is fitted with devices which at the transmitter generate a specified
continuous tone during transmission and at the receiver respond to a specific continuous tone.
ETSI

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8 ETSI TS 103 236 V1.1.1 (2014-01)
The CTCSS code frequency is the assigned tone frequency. The standard frequencies available for assignment are given
in table 1.
Table 1: CTCSS Code Frequencies
Freq Freq Freq Freq
(Hz) (Hz) (Hz) (Hz)
67,0 94,8 131,8 186,2
69,3 97,4 136,5 192,8
71,9 100,0 141,3 203,.5
74,4 103,5 146,2 210,7
77,0 107,2 151,4 218,1
79,7 110,9 156,7 225,7
82,5 114,8 162,2 233,6
85,4 118,.8 167,9 241,8
88,5 123,0 173,8 250,3
91,5 127,3 179,9

4.2 DCS
4.2.1 DCS codewords
The DCS codeword is a specific digitally coded signal transmitted continuously on the carrier frequency. The DCS
codework consists of a 23 bit frame which is transmitted at 134,4 bit/s.
The structure of the codeword is shown in figure 1. Bits 1 to 9 are the originating DCS code and are normally expressed
as a 3 digit octal number where bit 1 is the LSB. Bits 12 to 10 are fixed at 100 . Bits 13 to 23 are check bits generated
2
by a (23,12) cyclic Golay code.

Figure 1: DCS codeword structure
The LSB is transmitted first (bit 1).
4.2.2 DCS codewords
Allowable codewords are shown in table 2. DCS codes may be separated in four groups as follows:
Group 1: codes have 3 contiguous bits (lowest frequency 22,33 Hz)
Group 2: codes have 4 contiguous bits (lowest frequency 16,75 Hz)
Group 3: codes have 5 contiguous bits (lowest frequency 13,40 Hz)
Group 4: codes have 6 contiguous bits (lowest frequency 11,17 Hz)
ETSI

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9 ETSI TS 103 236 V1.1.1 (2014-01)
Table 2: DCS Codewords
Octal Bit Pattern Octal Bit Pattern
Code MSB          LSB Code MSB         LSB
023 11101100011100000010011 162 11010111100100001110010
025 11010110111100000010101 165 01100011101100001110101
026 11001011101100000010110 172 00001011111100001111010
031 10100011111100000011001 174 00110001011100001111100
032 10111110101100000011010 205 11011101001100010000101
043 10110110110100000100011 223 11010001110100010010011
047 00011111101100000100111 226 11110110000100010010110
051 11111001010100000101001 243 10001011011100010100011
054 11011110100100000101100 244 00111111010100010100100
065 10111010001100000110101 245 10110001111100010100101
071 11001111001100000111001 251 11000100111100010101001
072 11010010011100000111010 261 00101110111100010110001
073 01011100110100000111011 263 10111101000100010110011
074 11101000111100000111100 265 10000111100100010110101
114 01101011110100001001100 271 11110010100100010111001
115 11100101011100001001101 306 00011001111100011000110
116 11111000001100001001110 311 01110001101100011001001
125 00001111011100001010101 315 11011000110100011001101
131 01111010011100001011001 331 01000111110100011011001
132 01100111001100001011010 343 01010010111100011100011
134 01011101101100001011100 346 01110101001100011100110
143 01101111010100001100011 351 00011101011100011101001
152 00111101100100001101010 364 11010000101100011110100
155 10001001101100001101101 365 01011110000100011110101
156 10010100111100001101110 371 00101011000100011111001
411 11101110110100100001001 606 10111011001100110000110
412 11110011100100100001010 612 11001110001100110001010
413 01111101001100100001011 624 00011110101100110010100
423 10010111001100100010011 627 00000011111100110010111
431 11011000101100100011001 631 11100101000100110011001
432 11000101111100100011010 632 11111000010100110011010
445 11110111000100100100101 654 10011000011100110101100
464 01001111110100100110100 662 01001000111100110110010
465 11000001011100100110101 664 01110010011100110110100
466 11011100001100100110110 703 01000101011100111000011
503 01111000110100101000011 712 00010111101100111001010
506 01011111000100101000110 723 01110011000100111010011
516 10000011011100101001110 731 00111100100100111011001
532 00011100011100101011010 732 00100001110100111011010
546 00110011110100101100110 734 00011011010100111011100
565 00011000111100101110101 743 00101001101100111100011
754 01000001111100111101100

4.2.3 DCS Modulation
DCS Modulation is a NRZ baseband FSK modulation. The polarity of the modulation shall be a negative frequency
shift for a 0 and a positive frequency shift for a 1.
5 Test conditions, power sources and ambient
temperatures
5.1 Normal and extreme test conditions
Testing shall be performed under normal test conditions, and also, where stated, under extreme test conditions.
The test conditions and procedures shall be as specified in clauses 5.2 to 5.5.
ETSI

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10 ETSI TS 103 236 V1.1.1 (2014-01)
5.2 Test power source
During testing the power source of the equipment shall be replaced by a test power source capable of producing normal
and extreme test voltages as specified in clauses 5.3.2 and 5.4.2. The internal impedance of the test power source shall
be low enough for its effect on the test results to be negligible. For the purpose of tests, the voltage of the power source
shall be measured at the input terminals of the equipment.
For battery operated equipment the battery shall be removed and the test power source shall be applied as close to the
battery terminals as practicable.
During tests of DC powered equipment the power source voltages shall be maintained within a tolerance of < ±1 %
relative to the voltage at the beginning of each test. The value of this tolerance is critical for power measurements.
Using a smaller tolerance will provide better measurement uncertainty values.
5.3 Normal test conditions
5.3.1 Normal temperature and humidity
The normal temperature and humidity conditions for tests shall be any convenient combination of temperature and
humidity within the following ranges:
• temperature: +15 °C to +35 °C;
• relative humidity: 20 % to 75 %.
When it is impracticable to carry out the tests under these conditions, a note to this effect, stating the ambient
temperature and relative humidity during the tests, shall be added to the test report.
5.3.2 Normal test power source
5.3.2.1 Mains voltage
The normal test voltage for equipment to be connected to the mains shall be the nominal mains voltage. For the purpose
of the present document, the nominal voltage shall be the declared voltage or any of the declared voltages for which the
equipment was designed.
The frequency of the test power source corresponding to the ac mains shall be between 49 Hz and 51 Hz.
5.3.2.2 Regulated lead-acid battery power sources used on vehicles
When the radio equipment is intended for operation from the usual types of regulated lead-acid battery power source
used on vehicles the normal test voltage shall be 1,1 times the nominal voltage of the battery (for nominal voltages of
6 V and 12 V, these are 6,6 V and 13,2 V respectively).
5.3.2.3 Other power sources
For operation from other power sources or types of battery (primary or secondary), the normal test voltage shall be that
declared by the equipment manufacturer.
ETSI

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11 ETSI TS 103 236 V1.1.1 (2014-01)
5.4 Extreme test conditions
5.4.1 Extreme temperatures
For tests at extreme temperatures, measurements shall be made in accordance with the procedures specified in
clause 5.5, at the upper and lower temperatures of one of the following two ranges:
• -20 °C to +55 °C;
All mobile and handportable equipment.
Base stations for outdoor/uncontrolled climate conditions.
• 0 °C to +40 °C;
Base stations for indoor/controlled climate conditions.
In the case of base station equipment, the manufacturer shall declare which conditions the equipment is intended to be
installed in.
5.4.2 Extreme test source voltages
5.4.2.1 Mains voltage
The extreme test voltage for equipment to be connected to an ac mains source shall be the nominal mains voltage
±10 %.
5.4.2.2 Regulated lead-acid battery power sources used on vehicles
When the equipment is intended for operation from the usual types of regulated lead-acid battery power sources used on
vehicles the extreme test voltages shall be 1,3 and 0,9 times the nominal voltage of the battery (for a nominal voltage of
6 V, these are 7,8 V and 5,4 V respectively and for a nominal voltage of 12 V, these are 15,6 V and 10,8 V
respectively).
5.4.2.3 Power sources using other types of batteries
The lower extreme test voltages for equipment with power sources using batteries shall be as follows:
- for the nickel metal-hydride, leclanché or lithium type: 0,85 times the nominal battery voltage;
- for the mercury or nickel-cadmium type: 0,9 times the nominal battery voltage.
No upper extreme test voltages apply.
In the case where no upper extreme test voltage the nominal voltage is applicable, the corresponding four extreme test
conditions are:
• V /T , V /T ;
min min min max
• (V = nominal)/T , (V = nominal)/T .
max min max max
5.4.2.4 Other power sources
For equipment using other power sources, or capable of being operated from a variety of power sources, the extreme
test voltages shall be those declared by the equipment manufacturer.
ETSI

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12 ETSI TS 103 236 V1.1.1 (2014-01)
5.5 Procedure for tests at extreme t
...