SIST EN 300 396-2 V1.3.1:2006

• Abstract:

  This multi-part deliverable defines the TErrestrial Trunked RAdio system (TETRA) Direct Mode Operation (DMO). It specifies the basic air interface, the interworking between Direct Mode (DM) groups via repeaters, and interworking with the TETRA Voice plus Data (V+D) system via gateways. It also specifies the security aspects in TETRA DMO, and the intrinsic services that are supported in addition to the basic bearer and teleservices. The present document applies to the TETRA DMO Mobile Station - Mobile Station (MS - MS) air interface and contains the specifications of the physical layer according to the OSI seven layer reference model.; It establishes the TETRA DM radio aspects (layer 1 and lower MAC):; -it defines and specifies the modulation;; -it defines and specifies the radio transmission and reception;; -it defines and specifies the synchronization;; -it defines and specifies the channel coding;; -it defines and specifies the channel multiplexing;; -it defines and specifies the control over the radio link.

• Status: Published
• Publication Date: 30-Nov-2006
• ICS: 33.070.10 - Terrestrial Trunked Radio (TETRA)
• Technical Committee: MOC - Mobile Communications
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Dec-2006
• Due Date: 01-Dec-2006
• Completion Date: 01-Dec-2006
• Ref Project: ETSI EN 300 396-2 V1.3.1 (2006-09) - Terrestrial Trunked Radio (TETRA); Technical requirements for Direct Mode Operation (DMO); Part 2: Radio aspects

SIST EN 300 396-2 V1.3.1:2006 is the SIST adoption of ETSI EN 300 396-2 Version 1.3.1. It specifies the radio aspects of Terrestrial Trunked Radio (TETRA) Direct Mode Operation (DMO) for the Mobile Station - Mobile Station (MS - MS) air interface, including modulation, transmission and reception, synchronization, channel coding, channel multiplexing, and radio link control. Engineers, equipment makers, test labs, and buyers use it to check how TETRA DMO radios should behave on the air interface.

What does SIST EN 300 396-2 V1.3.1:2006 specify?

SIST EN 300 396-2 V1.3.1:2006 specifies the TETRA DMO radio layer for the MS-MS air interface and the physical layer of the OSI seven-layer model. It is part 2 of the DMO multi-part deliverable, and the foreword places it alongside the other parts of the same series.

Clause / annex	What it covers
Clause 4	Radio aspects overview and the reference configuration
Clause 5	Modulation
Clause 6	Radio transmission and reception
Clause 7	Radio subsystem synchronization
Clause 8	Channel coding and scrambling
Clause 9	Channel multiplexing for DM
Clause 10	Radio subsystem link control
Annex A	Bibliography
Annex B	Change requests

The foreword identifies the related DMO parts as general network design, MS-MS air interface protocol, Type 1 repeater air interface, gateway air interface, security, Type 2 repeater air interface, PICS proforma specification, and Managed Direct Mode Operation (M-DMO).

What are the key requirements of SIST EN 300 396-2 V1.3.1:2006?

SIST EN 300 396-2 V1.3.1:2006 sets the radio behavior, timing, coding, and test conditions that TETRA DMO equipment has to meet. The most important points are the modulation method, the RF channel arrangement, the transmitter and receiver limits, the synchronization rules, and the channel coding and burst structures.

Modulation and frame timing

Clause 5 fixes the baseband modulation as π/4-shifted Differential Quaternary Phase Shift Keying (π/4-DQPSK) at 36 kbit/s with a root-raised cosine filter and roll-off factor 0,35. The symbols are generated by differential encoding, so each symbol depends on the previous one.

In practice, this defines the waveform a radio must produce and what a test lab checks on the signal constellation and symbol timing. Clause 9 also fixes the DMO framing structure: 1 multiframe contains 18 frames, 1 frame contains 4 timeslots, and 1 timeslot contains 510 modulation bit durations.

Radio transmission, reception, and measurement

Clause 6 applies to TETRA systems operating from 300 MHz to 1 GHz. DM-MSs transmit and receive only on RF carriers allocated for TETRA DMO, and the RF carrier separation is 25 kHz.

The clause also requires measurement at an antenna connector, using the manufacturer-specified test point. It covers output power, power classes, unwanted conducted and radiated emissions, RF output power time masking, blocking, spurious response rejection, intermodulation response rejection, and receiver performance. For a buyer or integrator, this is the part that tells a lab how to verify coexistence with nearby channels and whether the receiver can still work under interference.

Clause 6.6 sets modulation accuracy and receiver performance. The RMS vector error in any burst shall be less than 0,1 and the peak vector error magnitude shall be less than 0,3 for any symbol. Receiver criteria are given for logical channels such as SCH/S, SCH/H, SCH/F, TCH/7,2, TCH/4,8, TCH/2,4, and STCH under DU50, DR50, and static propagation conditions.

Synchronization and master-slave behavior

Clause 7 defines master and slave operation for DMO. The master DM-MS provides the synchronization reference and transmits synchronization bursts, while the slave DM-MS derives frequency and time from the master.

This matters because DMO radios must line up their burst timing without network help. Clause 7 requires the DM-MS frequency reference source to be accurate to better than ±1,0 kHz and the timebase to better than ±2 ppm. It also sets the post-synchronization burst timing and frequency accuracy for slave transmissions, and it adds special rules for a master MS on channel B in frequency efficient mode.

Channel coding, scrambling, and burst structure

Clause 8 defines the error control chain for each logical channel. It uses a sequence of block coding, convolutional coding, reordering and interleaving, scrambling, and then multiplexing into the burst structure.

For the traffic channels TCH/4,8 and TCH/2,4, the clause uses interleaving over N blocks, with N pre-set at call set-up and allowed values of 1, 4, or 8. Clause 9 then turns these coded bits into the physical bursts: Direct Mode Linearization Burst (DLB), Direct Mode Normal Burst (DNB), and Direct Mode Synchronization Burst (DSB). It also defines the logical channels SCH/S, SCH/H, SCH/F, STCH, and the mapping of bits into the burst fields.

Link control

Clause 10 covers radio subsystem link control. In direct DM-MS to DM-MS operation, a master MS transmits at nominal power according to the transmitter clauses, and radio link measurements may use signal strength or signal quality.

In practice, this is the part that supports power handling and link monitoring during DMO operation. It gives the basis for deciding whether the link is healthy enough for continued communication.

What terms does SIST EN 300 396-2 V1.3.1:2006 define?

SIST EN 300 396-2 V1.3.1:2006 defines the core DMO terms used throughout the clauses and measurement tables.

• Direct Mode Operation (DMO) - simplex operation where mobile subscriber radio units communicate outside the control of the TETRA TMO network, without base station intervention.
• Direct Mode Mobile Station (DM-MS) - the physical grouping of equipment used to obtain TETRA DM services; it can act as master or slave for synchronization.
• master - the DM-MS that provides synchronization information to the channel by transmitting traffic, control data, or channel reservation signaling.
• slave - the DM-MS that receives traffic or signaling and derives synchronization information from the channel.
• Trunked Mode Operation (TMO) - operation where MSs communicate through the TETRA V+D air interface controlled by the SwMI.
• Bit Error Ratio (BER) - the ratio of wrongly received bits to all bits received in a logical channel.
• Message Erasure Rate (MER) - the ratio of messages detected as wrong to all messages received in a logical channel.
• Probability of Undetected Erroneous Message (PUEM) - the ratio of erroneous messages that the receiver counts as right to all messages received in a logical channel.

Who uses SIST EN 300 396-2 V1.3.1:2006?

SIST EN 300 396-2 V1.3.1:2006 is used by people who design, test, approve, or buy TETRA DMO radio equipment. It is especially relevant where direct-mode voice and data radios must interoperate on a defined RF channel structure.

Typical users include:

• radio and modem designers working on modulation, timing, and burst formatting
• RF test laboratories measuring emissions, sensitivity, blocking, and synchronization
• conformance and certification teams checking transmitter and receiver behavior
• procurement and technical evaluation teams comparing DMO equipment
• organizations operating TETRA land mobile radio systems that need direct-mode communication

What changed in SIST EN 300 396-2 V1.3.1:2006 from the previous edition?

Annex B records change request 002 03 against version 1.2.1. It lists editorial changes in the foreword, clause 2, clauses 3.1 and 3.2, clause 4.8, clause 6.2, clause 6.5.3.1, clause 7.1, clause 9.3.1, and clause 10.3.2.

Which standards are used with SIST EN 300 396-2 V1.3.1:2006?

Clause 2 names the documents that form the normative basis for this part. The foreword and bibliography also identify companion parts and related TETRA standards.

Standard	What it contributes
ETSI EN 300 113-1	Technical characteristics and methods of measurement for land mobile radio equipment using constant or non-constant envelope modulation
ETSI EN 300 396-3	MS-MS Air Interface (AI) protocol for DMO
ETSI EN 300 395-2	Speech codec for the full-rate traffic channel, TETRA codec
ETSI TS 100 392-15	TETRA frequency bands, duplex spacings, and channel numbering
ETSI EN 300 392-1	Background on TETRA V+D general network design
ETSI EN 300 392-2	Background on the TETRA V+D air interface

The foreword also places this standard within the DMO series parts 1, 4, 5, 6, 7, 8, and 10.

What does the SIST EN 300 396-2 V1.3.1:2006 document contain?

SIST EN 300 396-2 V1.3.1:2006 contains equations, block diagrams, timing structures, burst layouts, and tables of RF and performance limits. Clause 5 gives the modulation equations and constellation behavior, while clause 6 gives emission masks, power rules, blocking and sensitivity tables, and receiver test conditions.

Clause 7 contains the synchronization rules and counter relationships for master and slave DM-MS operation. Clause 8 contains the coding, interleaving, and scrambling structures, and clause 9 contains the burst definitions, bit numbering, preambles, training sequences, and frame structure figures. These are the parts a designer, test engineer, or certification lab uses to build, measure, and verify a DMO radio.

SLOVENSKI STANDARD
01-december-2006
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Terrestrial Trunked Radio (TETRA); Technical requirements for Direct Mode Operation
(DMO); Part 2: Radio aspects
Ta slovenski standard je istoveten z: EN 300 396-2 Version 1.3.1
ICS:
33.070.10 Prizemni snopovni radio Terrestrial Trunked Radio
(TETRA) (TETRA)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

European Standard (Telecommunications series)

Terrestrial Trunked Radio (TETRA);
Technical requirements for Direct Mode Operation (DMO);
Part 2: Radio aspects
2 ETSI EN 300 396-2 V1.3.1 (2006-09)

Reference
REN/TETRA-08146
Keywords
air interface, radio, TETRA
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ETSI
3 ETSI EN 300 396-2 V1.3.1 (2006-09)
Contents
Intellectual Property Rights.6
Foreword.6
1 Scope.7
2 References.7
3 Definitions and abbreviations.8
3.1 Definitions.8
3.2 Abbreviations.9
4 Radio aspects.10
4.1 Introduction.10
4.2 Set of logical channels.10
4.3 Reference configuration.10
4.4 Error control schemes.11
4.5 Timeslot structure.11
4.5.1 Framing structure.11
4.5.2 Timeslots and bursts .12
4.5.3 Mapping of logical channels onto physical channels.12
4.6 Coding, interleaving and scrambling.12
4.7 Modulation.12
4.8 Transmission and reception.12
4.9 Other radio-related functions.12
4.10 Performance.12
5 Modulation.13
5.1 Introduction.13
5.2 Modulation type.13
5.3 Modulation rate.13
5.4 Modulation symbol definition .13
5.5 Modulated signal definition.14
5.6 Modulation filter definition .14
5.7 Modulation block diagram .15
6 Radio transmission and reception.15
6.1 Introduction.15
6.2 Frequency bands and channel arrangement.15
6.3 Reference test planes .15
6.4 Transmitter characteristics.15
6.4.1 Output power.15
6.4.2 Power classes.16
6.4.3 Unwanted conducted emissions.16
6.4.3.1 Definitions.16
6.4.3.2 Unwanted emissions close to the carrier .16
6.4.3.2.1 Emissions during the useful part of the burst .17
6.4.3.2.2 Emissions during the switching transients.17
6.4.3.3 Unwanted emissions far from the carrier .17
6.4.3.3.1 Discrete spurious.17
6.4.3.3.2 Wideband noise.18
6.4.3.4 Unwanted emissions during the Linearization CHannel (LCH).19
6.4.3.5 Unwanted emissions in the non-transmit state .19
6.4.4 Unwanted radiated emissions .19
6.4.5 Radio frequency tolerance .19
6.4.6 RF output power time mask.19
6.4.7 Transmitter intermodulation attenuation.20
6.4.7.1 Definition.20
6.4.7.2 Specification.20
6.5 Receiver characteristics.21
ETSI
4 ETSI EN 300 396-2 V1.3.1 (2006-09)
6.5.1 Blocking characteristics.21
6.5.1.1 Definition.21
6.5.1.2 Specification.21
6.5.2 Spurious response rejection .21
6.5.2.1 Definition.21
6.5.2.2 Specification.21
6.5.3 Intermodulation response rejection.22
6.5.3.1 Definition.22
6.5.3.2 Specification.22
6.5.4 Unwanted conducted emissions.22
6.5.4.1 Definition.22
6.5.4.2 Specification.22
6.5.5 Unwanted radiated emissions .22
6.6 Transmitter/receiver performance.23
6.6.1 Modulation accuracy.23
6.6.1.1 Ideal case.23
6.6.1.2 Vector error magnitude requirement at symbol time .23
6.6.2 Receiver performance.24
6.6.2.1 Nominal error rates .24
6.6.2.2 Dynamic reference sensitivity.24
6.6.2.3 Receiver performance at reference interference ratios .25
6.6.2.4 Static reference sensitivity .25
6.6.2.5 MS receiver performance for acquisition of synchronization burst .26
6.6.3 Propagation conditions.26
6.6.3.1 Tap-gain process types.26
6.6.3.2 DM propagation models.27
7 Radio sub-system synchronization.27
7.1 Introduction.27
7.2 Definitions and general requirements for synchronization of DM-MSs.27
7.3 Timebase counters.28
7.3.1 Definition of counters .28
7.3.2 Relationship between the counters.28
7.4 Requirements for the frequency reference source of DM mobiles .29
7.5 Requirements for the synchronization of a slave DM mobile .29
7.6 Synchronization requirements for a master MS operating on channel B in frequency efficient mode .29
8 Channel coding and scrambling .30
8.1 Introduction.30
8.2 General.30
8.2.1 Interfaces in the error control structure.30
8.2.2 Notation.31
8.2.3 Definition of error control codes.32
8.2.3.1 16-state Rate-Compatible Punctured Convolutional (RCPC) codes .32
8.2.3.1.1 Encoding by the 16-state mother code of rate 1/4 .32
8.2.3.1.2 Puncturing of the mother code.32
8.2.3.1.3 Puncturing scheme of the RCPC code of rate 2/3.33
8.2.3.1.4 Puncturing scheme of the RCPC code of rate 292/432.33
8.2.3.1.5 Puncturing scheme of the RCPC code of rate 148/432.33
8.2.3.2 (K + 16, K ) block code .33
1 1
8.2.4 Definition of interleaving schemes .33
8.2.4.1 Block interleaving.33
8.2.4.2 Interleaving over N blocks .34
8.2.5 Definition of scrambling.34
8.2.5.1 Scrambling method.34
8.2.5.2 Scrambling sequence.34
8.3 Error control schemes.35
8.3.1 Signalling channels.35
8.3.1.1 Synchronization Signalling CHannel (SCH/S) .35
8.3.1.2 Half-slot Signalling CHannel (SCH/H) and Stealing CHannel (STCH).36
8.3.1.3 Full-slot Signalling CHannel (SCH/F).37
8.3.2 Traffic channels in circuit switched mode .37
ETSI
5 ETSI EN 300 396-2 V1.3.1 (2006-09)
8.3.2.1 Traffic channel, net rate = 7,2 kbit/s (TCH/7,2).37
8.3.2.2 Traffic channel, net rate = 4,8 kbit/s (TCH/4,8).38
8.3.2.3 Traffic channel, net rate = 2,4 kbit/s (TCH/2,4).39
8.3.2.4 Speech Traffic Channel, full slot (TCH/S).40
8.3.2.5 Speech Traffic Channel, half slot (TCH/S) .40
9 Channel multiplexing for DM .40
9.1 Introduction.40
9.2 Logical channels.40
9.2.1 Logical channels hierarchy .40
9.2.2 Traffic channels.41
9.2.3 Control channels.41
9.2.3.1 General.41
9.2.3.2 Linearization CHannel (LCH).41
9.2.3.3 Signalling CHannel (SCH).41
9.2.3.4 STealing CHannel (STCH) .41
9.3 The physical resource.41
9.3.1 General.41
9.3.2 Timeslots.42
9.3.3 DM frame.42
9.3.4 Multiframe.42
9.4 Physical channels.42
9.4.1 General.42
9.4.2 Bursts.42
9.4.2.1 General.42
9.4.2.2 Modulation symbol numbering.42
9.4.2.3 Modulation bit numbering.43
9.4.2.4 Burst timing.43
9.4.3 Type of bursts .43
9.4.3.1 General.43
9.4.3.2 Modulation bits allocation.44
9.4.3.2.1 DM Normal Burst (DNB).44
9.4.3.2.2 DM Linearization Burst (DLB) .44
9.4.3.2.3 DM Synchronization Burst (DSB) .44
9.4.3.3 Burst fields.45
9.4.3.3.1 Frequency correction field.45
9.4.3.3.2 Inter-slot frequency correction field .45
9.4.3.3.3 Normal training sequence and preamble .45
9.4.3.3.4 Synchronization training sequence.46
9.4.3.3.5 Phase adjustment bits .46
9.4.3.3.6 Tail bits.46
9.4.4 DM-MS multiple slot transmission.47
9.4.5 General mapping of logical channels.47
10 Radio subsystem link control .47
10.1 Introduction.47
10.2 RF power control.47
10.3 Radio link measurements.48
10.3.1 Signal strength.48
10.3.2 Signal quality.48
Annex A (informative): Bibliography.49
Annex B (informative): Change requests .50
History .51

ETSI
6 ETSI EN 300 396-2 V1.3.1 (2006-09)
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://webapp.etsi.org/IPR/home.asp).
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 European Standard (Telecommunications series) has been produced by ETSI Technical Committee Terrestrial
Trunked Radio (TETRA).
The present document is part 2 of a multi-part deliverable covering the Terrestrial Trunked Radio (TETRA); Technical
requirements for Direct Mode Operation (DMO), as identified below:
Part 1: "General network design";
Part 2: "Radio aspects";
Part 3: "Mobile Station to Mobile Station (MS-MS) Air Interface (AI) protocol";
Part 4: "Type 1 repeater air interface";
Part 5: "Gateway air interface";
Part 6: "Security";
Part 7: "Type 2 repeater air interface";
Part 8: "Protocol Implementation Conformance Statement (PICS) proforma specification";
Part 10: "Managed Direct Mode Operation (M-DMO)".
NOTE: Part 8 (PICS) of this multi-part deliverable is of status "historical" and will not be updated according to
this version of the standard.
National transposition dates
Date of adoption of this EN: 1 September 2006
Date of latest announcement of this EN (doa): 31 December 2006
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 30 June 2007
Date of withdrawal of any conflicting National Standard (dow): 30 June 2007

ETSI
7 ETSI EN 300 396-2 V1.3.1 (2006-09)
1 Scope
This multi-part deliverable defines the TErrestrial Trunked RAdio system (TETRA) Direct Mode Operation (DMO). It
specifies the basic air interface, the interworking between Direct Mode (DM) groups via repeaters, and interworking
with the TETRA Voice plus Data (V+D) system via gateways. It also specifies the security aspects in TETRA DMO,
and the intrinsic services that are supported in addition to the basic bearer and teleservices.
The present document applies to the TETRA DMO Mobile Station - Mobile Station (MS - MS) air interface and
contains the specifications of the physical layer according to the OSI seven layer reference model.
It establishes the TETRA DM radio aspects (layer 1 and lower MAC):
• it defines and specifies the modulation;
• it defines and specifies the radio transmission and reception;
• it defines and specifies the synchronization;
• it defines and specifies the channel coding;
• it defines and specifies the channel multiplexing;
• it defines and specifies the control over the radio link.
2 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present
document.
• References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• For a non-specific reference, the latest version applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
[1] ETSI EN 300 113-1: "Electromagnetic compatibility and Radio spectrum Matters (ERM); Land
mobile service; Radio equipment intended for the transmission of data (and/or speech) using
constant or non-constant envelope modulation and having an antenna connector; Part 1: Technical
characteristics and methods of measurement".
[2] ETSI EN 300 396-3: "Terrestrial Trunked Radio (TETRA); Technical requirements for Direct
Mode Operation (DMO); Part 3: Mobile Station to Mobile Station (MS-MS) Air Interface (AI)
protocol".
[3] ETSI EN 300 395-2: "Terrestrial Trunked Radio (TETRA); Speech codec for full-rate traffic
channel; Part 2: TETRA codec".
[4] ETSI TS 100 392-15: "Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D);
Part 15: TETRA frequency bands, duplex spacings and channel numbering".
ETSI
8 ETSI EN 300 396-2 V1.3.1 (2006-09)
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
Bit Error Ratio (BER): ratio of the bits wrongly received to all bits received in a given logical channel
call transaction: all of the functions associated with a complete unidirectional transmission of information
NOTE: A call is made up of one or more call transactions.
changeover: within a call, process of effecting a transfer of the master role (and hence transmitting MS) at the end of
one call transaction so that another can commence
Direct Mode Operation (DMO): mode of simplex operation where mobile subscriber radio units may communicate
using radio frequencies which may be monitored by, but which are outside the control of, the TETRA TMO network
NOTE: Direct Mode Operation is performed without intervention of any base station.
Direct Mode Mobile Station (DM-MS): physical grouping that contains all of the mobile equipment that is used to
obtain TETRA DM services
NOTE: For synchronization purposes, Direct Mode Mobile Stations can have one of two status levels:
master: if the DM-MS is either active in a call transaction transmitting traffic or control data, or is
reserving the channel by means of channel reservation signalling and hence is providing
synchronization information to the channel;
slave: if the DM-MS is receiving traffic and/or signalling and hence is deriving synchronization
information from the channel.
DM channel: specific grouping of timeslots in the DM multiplex structure related to a particular DM RF carrier
(i.e. DM frequency)
NOTE: The grouping may not always be fixed, but in DMO when operating in frequency efficient mode as an
example, there are two DM channels, identified by the letters A and B.
DUal mode switchable Mobile Station (DU-MS): MS that is capable to operate in TETRA DMO or in TETRA TMO
one mode at a time
NOTE: Only one mode can be selected at any given time and the MS is not capable of monitoring a DM RF
carrier while in TMO or a TMO channel while in DMO.
Dual Watch Mobile Station (DW-MS): MS that is either full dual watch MS (F-DW-MS) or idle dual watch MS
(I-DW-MS)
NOTE: When idle, the MS periodically monitors both the DM RF carrier and the TMO control channel. If the MS
is performing full dual watch, it is also capable of periodically monitoring the TMO control channel while
in a DM call and a DM RF carrier while in a TMO call. Alternatively the MS may perform idle dual
watch, in which case it need not be capable of monitoring the TMO control channel while involved in a
DM activity (e.g. call) or a DM RF carrier while involved in a TMO activity (e.g. call).
frequency efficient mode: mode of operation where two independent DM communications are supported on a single
RF carrier
NOTE: In frequency efficient mode the two DM channels are identified as channel A and channel B.
logical channel: any distinct data path
NOTE: Logical channels are considered to operate between logical endpoints.
Message Erasure Rate (MER): ratio of the messages detected as wrong by the receiver to all messages received in a
given logical channel
ETSI
9 ETSI EN 300 396-2 V1.3.1 (2006-09)
normal mode: mode of operation where only one DM communication is supported on an RF carrier
occupation: time where a call transaction is in progress on a channel
pre-emption: transfer of the master role to the requested DM-MS
NOTE: This process may occur within a call during occupation or to set-up a new call during either occupation or
reservation.
Probability of Undetected Erroneous Message (PUEM): limit ratio of the erroneous messages detected as right by
the receiver to all messages received in a given logical channel
quarter symbol number: timing of quarter symbol duration 125/9 µs within a burst
radio frequency carrier (RF carrier): radio frequency channel
NOTE: This is a specified portion of the RF spectrum. In DMO, the RF carrier separation is 25 kHz.
reservation: time where a "channel reservation" signal is present on the channel
simplex: mode of working in which information can be transferred in both directions but not at the same time
timebase: device which determines the timing state of signals transmitted by a Direct Mode Mobile Station
timeslot number: counter indicating the timing of timeslots within a DMO frame
Trunked Mode Operation (TMO): mode of operation where MSs communicate via the TETRA V+D air interface
which is controlled by the TETRA Switching and Management Infrastructure (SwMI)
NOTE: This is also called V+D operation. The abbreviation "TMO" is used in the present document to pair with
the abbreviation "DMO" instead of the abbreviation "V+D". "TMO" abbreviation is not used in
EN 300 392-1 and EN 300 392-2.
useful part of a burst: part of the burst between and including the symbol time of SN0 and the symbol time of SNmax,
with SN0 and SNmax as defined in clause 9 of EN 300 396-2
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AI Air Interface
BER Bit Error Ratio
BN Bit Number
DLB Direct mode Linearization Burst
DLL Data Link Layer
DM-MS Direct Mode Mobile Station
DMO Direct Mode Operation
DNB Direct mode Normal Burst
DR50 DM propagation model Rural area for 50 km/h
DQPSK Differential Quaternary Phase Shift Keying
DSB Direct mode Synchronization Burst
DU50 DM propagation model Urban area for 50 km/h
DU-MS Dual mode (TMO - DMO) switchable Mobile Station
DW-MS Dual Watch Mobile Station
FN Frame Number
LCH Linearization CHannel
MAC Medium Access Control
MER Message Erasure Rate
mod modulo (base for counting)
MS Mobile Station
PA Power Amplifier
PACQ Probability of synchronization burst ACQuisition
PUEM Probability of Undetected Erroneous Message
QN Quarter symbol Number
ETSI
10 ETSI EN 300 396-2 V1.3.1 (2006-09)
RCPC Rate-Compatible Punctured Convolutional
RF Radio Frequency
RMS Root Mean Square
SCH Signalling CHannel
SN Symbol Number
STCH STealing CHannel
TCH Traffic CHannel
TN Timeslot Number
TMO Trunked Mode Operation
4 Radio aspects
4.1 Introduction
Clause 4 is an introduction to the radio aspects of the TETRA DMO standard. It consists of a general description of the
organization of the radio-related functions with reference to the clauses where each part is specified in detail.
Furthermore, it introduces the reference configuration that will be used throughout the present document.
4.2 Set of logical channels
The radio subsystem provides a certain number of logical channels as defined in clause 9. The logical channels
represent the interface between the protocol and the radio.
4.3 Reference configuration
For the purpose of elaborating the specification of the radio-related functions, a reference configuration of the
transmission chain is used, as shown in figure 1. Only the transmission part is specified, the receiver being specified
only via the overall performance requirements. With reference to this configuration, the clauses address the following
functional units:
• clause 5: differential encoding and modulation;
• clause 6: characteristics of transmitter and receiver;
• clause 8: coding, reordering and interleaving, and scrambling;
• clause 9: burst building and logical channel multiplexing;
• clause 10: radio link measurements.
This reference configuration also defines a number of points of vocabulary in relation to the names of bits at different
levels in the configuration.
ETSI
11 ETSI EN 300 396-2 V1.3.1 (2006-09)
(1) (3)
(2) (4) (5)
RE-ORDERER AND LOGICAL CHANNEL
CONVOLUTIONAL
BLOCK ENCODER SCRAMBLER
INTERLEAVER MULTIPLEXER
ENCODER
(6)
(1) type-1 information bits (transmit) BURST BUILDER
(2) type-2 block encoded bits
(7)
(3) type-3 convolutionally encoded bits
DIFFERENTIAL
ENCODER
(4) type-4 re-ordered and interleaved bits
(8)
(5) type-5 scrambled bits
MODULATOR
(6) multiplexed bits
(7) modulation bits
TRANSMITTER
(8) modulation symbols
Figure 1: Reference configuration
4.4 Error control schemes
The different error control schemes are described in detail in clause 8.
4.5 Timeslot structure
The carrier separation is 25 kHz.
The basic radio resource is a timeslot lasting 14,167 ms (85/6 ms) and transmitting information at a modulation rate of
36 kbit/s. This means that the timeslot duration, including guard and ramping times, is 510 bit (255 symbol) durations.
The following clauses briefly introduce the structures of multiframes, frames, timeslots and bursts, as well as the
mapping of the logical channels onto the physical channels. The appropriate specifications are found in clause 9.
4.5.1 Framing structure
A diagrammatic representation of the framing structure is shown in figure 2.
1 multiframe = 18 frames  ( = 1,02 s )
12 3 451178
control frame
1 frame = 4 timeslots (
~ 56,67ms )
12 3
1 time slot = 510 modulation bits durations (  s )
14,167 m
~
12 3 4 509 510
1 modulation bit duration = 250/9 µs (~  µs)
27,78
Figure 2: DM framing structure
ETSI
12 ETSI EN 300 396-2 V1.3.1 (2006-09)
One multiframe is subdivided into 18 frames, and has a duration of 1,02 s. The eighteenth frame in a multiframe is a
control frame.
One frame is subdivided into 4 timeslots, and has a duration of 170/3 ≈ 56,67 ms.
4.5.2 Timeslots and bursts
The timeslot is a time interval of 85/6 ≈ 14,167 ms, which corresponds to 255 symbol durations.
The physical contents of a timeslot is carried by a burst. There are three different types of bursts, as defined in clause 9.
4.5.3 Mapping of logical channels onto physical channels
The mapping of the logical channels onto the physical channels, according to the mode of operation, is defined in
clause 9.
4.6 Coding, interleaving and scrambling
The coding, interleaving and scrambling schemes associated with each logical channel are specified in clause 8.
4.7 Modulation
The modulation scheme is π/4-DQPSK (Differential Quaternary Phase-Shift Keying) with root-raised cosine
modulation filter and a roll-off factor of 0,35. The modulation rate is 36 kbit/s. This scheme is specified in detail in
clause 5.
4.8 Transmission and reception
The modulated stream is transmitted on a radio frequency carrier.
The specific RF carrier, together with the requirements on the transmitter and the receiver characteristics are specified
in clause 6.
DM-MS power classes are defined in clause 6.
4.9 Other radio-related functions
Transmission involves other functions. These functions, which may necessitate the handling of specific protocols, are
the radio subsystem synchronization, and the radio subsystem link control.
The synchronization incorporates:
• frequency and time acquisition by the receiver;
• adjustment of the timebase in the DM-MS.
The requirements on synchronizatio
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