SIST ETS 300 144 E1:2003

Integrated Services Digital Network (ISDN); Audiovisual services Frame structure for a 64 kbit/s to 1 920 kbit/s channel and associated syntax for inband signalling

To specify a frame structure for in band signalling system using 64 kbit/s to 1929 kbit/s channels.

Digitalno omrežje z integriranimi storitvami (ISDN) – Avdiovizualne storitve – Struktura okvirov za kanale s hitrostmi od 64 kbit/s do 1 920 kbit/s in pripadajočo skladnjo za znotrajpasovno krmiljenje

General Information

• Status: Published
• Publication Date: 30-Nov-2003
• ICS: 33.080 - Integrated Services Digital Network (ISDN)
• Technical Committee: SS EIT - Technical Board for the electrotechnical, information technology and telecommunications fields
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Dec-2003
• Due Date: 01-Dec-2003
• Completion Date: 01-Dec-2003
• Ref Project: ETSI ETS 300 144 ed.1 (1994-05) - Integrated Services Digital Network (ISDN); Audiovisual services Frame structure for a 64 kbit/s to 1 920 kbit/s channel and associated syntax for inband signalling

Standards Content (Sample)

SLOVENSKI STANDARD
SIST ETS 300 144 E1:2003
01-december-2003
'LJLWDOQRRPUHåMH]LQWHJULUDQLPLVWRULWYDPL,6'1±$YGLRYL]XDOQHVWRULWYH±
6WUXNWXUDRNYLURY]DNDQDOHVKLWURVWPLRGNELWVGRNELWVLQSULSDGDMRþR
VNODGQMR]D]QRWUDMSDVRYQRNUPLOMHQMH
Integrated Services Digital Network (ISDN); Audiovisual services Frame structure for a
64 kbit/s to 1 920 kbit/s channel and associated syntax for inband signalling
Ta slovenski standard je istoveten z: ETS 300 144 Edition 1
ICS:
33.080 Digitalno omrežje z Integrated Services Digital
integriranimi storitvami Network (ISDN)
(ISDN)
SIST ETS 300 144 E1:2003 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ETS 300 144 E1:2003

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SIST ETS 300 144 E1:2003
EUROPEAN ETS 300 144
TELECOMMUNICATION May 1994
STANDARD
Source: ETSI TC-TE Reference: DE/TE-04117
ICS: 33.080
ISDN, audiovisual services, inband signalling
Key words:
Integrated Services Digital Network (ISDN);
Audiovisual services
Frame structure for a 64 kbit/s to 1 920 kbit/s channel
and associated syntax for inband signalling
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
F-06921 Sophia Antipolis CEDEX - FRANCE
Postal address:
650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
Office address:
c=fr, a=atlas, p=etsi, s=secretariat - [e-mail]
X.400: Internet:
Tel.: [phone] - Fax: [phone]
Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and the
foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 1994. All rights reserved.
New presentation - see History box

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Whilst every care has been taken in the preparation and publication of this document, errors in content,
typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to
"ETSI Editing and Committee Support Dept." at the address shown on the title page.

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Contents
Foreword .5
1 Scope .7
2 Normative references.7
3 Definitions.8
4 Symbols and abbreviations .9
5 Description .10
5.1 Frame Alignment Signal (FAS) .10
5.2 Bit-rate Allocation Signal (BAS) .11
5.3 Encryption Control Signal (ECS) channel (optional) .11
5.4 Remaining capacity.11
6 Frame structure.12
6.1 General .12
6.2 Multiframe structure.12
6.3 Gain, loss and recovery of frame alignment .14
6.4 Gain, loss and recovery of multiframe alignment.14
6.5 Procedure to recover octet timing from frame alignment .14
6.5.1 General rule.14
6.5.2 Particular cases.14
6.5.3 Search for Frame Alignment Signal (FAS).15
6.6 Frame structure for interworking between a 64 kbit/s terminal and a 56 kbit/s terminal
(optional).15
6.6.1 Operation of the 64 kbit/s terminal .16
6.6.2 Restriction against some communication modes.16
7 Multiple connections.16
7.1 Multiple B-connections.16
7.2 Multiple H0-connections.17
8 Introduction to BAS .17
8.1 Encoding of the BAS.17
8.2 Values of the BAS.18
8.2.1 Single octet BAS.19
8.2.2 Two-octet BAS .19
8.2.3 Multi-octet BAS (optional).19
9 Connection quality monitoring (optional) .19
9.1 Computation of the CRC4 bits .20
9.1.1 Multiplication-division process.20
9.1.2 Encoding procedure .20
9.1.3 Decoding procedure (optional).20
9.2 Consequent actions .20
9.2.1 Action on the E-bit .20
9.2.2 Additional monitoring for incorrect frame alignment (optional).21
9.2.3 Monitoring for error performance (optional) .21
10 Definitions and tables of BAS values .21
10.1 Single/first octet BAS values.21
10.1.1 Audio command values (000) .21
10.1.1.1 Unrestricted case.21
10.1.1.2 Restricted case.22

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10.1.2 Transfer-rate command values (001) . 23
10.1.3 Video, encryption, loopback and other commands (010) . 24
(12)
10.1.4 LSD/MLP commands (011) . 26
10.1.5 Audio capabilities (100) . 27
10.1.6 Transfer-rate capabilities (100). 27
10.1.7 Video, MBE and encryption capabilities (101) . 28
(13)
10.1.8 LSD/MLP capabilities (101) . 28
10.1.9 Escape table values (111) . 29
10.2 Second octet ("escaped'') BAS values . 31
10.2.1 HSD/H-MLP (High speed Multi layer Protocol) (111)[16] . 31
10.2.1.1 Capabilities (111)[16]-(101). 31
10.2.1.2 Commands (111)[16]-(011) . 31
10.2.2 Control and Indication (C&I) - (111)[17]. 33
10.2.2.1 C&I related to video (111)[17]-(000). 33
10.2.2.2 C&I related to audio (111)[17]-(000) . 33
10.2.2.3 C&I related to simple multipoint conferences not using
MLP (111)[17]-(001). 34
10.2.2.4 SBE symbols used in multipoint working (111)[17]-(000),
(001), (010), (011). 34
10.2.3 Applications within LSD/HSD channels (111)[18]. 38
10.2.3.1 Capabilities (111)[18]-(101). 38
10.2.3.2 Commands (111)[18]-(011) . 39
10.2.4 General purpose SBE symbols: SBE numbers reached by (111)[19] . 40
10.2.5 General purpose SBE symbols: SBE characters reached by (111)[20] . 40
10.3 Multiple-byte extension BAS values . 40
10.4 Bit positions occupied by combinations of BAS commands. 40
Annex A (informative): Bibliography . 46
History. 47

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Foreword
This European Telecommunication Standard (ETS) has been produced by the Terminal Equipment (TE)
Technical Committee of the European Telecommunications Standards Institute (ETSI).
The attention of the user of this ETS is drawn to the possibility that compliance may require the use of
technology covered by patent or similar rights.
ETSI is not responsible for identifying patent or similar rights or for granting licences which may be
required and, as a result, ETSI is not in a position to give authoritative or comprehensive information
concerning the existence, validity or scope of patent or similar rights in connection with this ETS.

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1 Scope
This ETS specifies the frame structure and the syntax for end-to-end inband signalling for audiovisual
services and end-to-end data communication between equipment using single or multiple digital channels
(B, H0, H11 or H12) up to 1 920 kbit/s when connected by the pan-European Integrated Services Digital
Network (ISDN). Digital audiovisual services are provided by a transmission system in which the relevant
signals are multiplexed onto a digital path. This frame structure allows the best use of the total
transmission capacity for the various data flows as audio, video, user data, telematic information and
special applications. Additionally, signals for the proper functioning of the system are included.
This ETS allows the synchronisation of multiple 64 kbit/s or 384 kbit/s connections and the control of the
multiplexing of audio, video, data and other signals within the synchronised multiconnection structure in
the case of multimedia services, such as videoconference.
It provides the means to transmit end-to-end inband signalling according to the procedures described in
ETS 300 143 [2].
This ETS is applicable to terminals or other equipment (e.g. Multipoint Conference Units) supporting
audiovisual applications.
A separate ETS is under preparation (DE/TE-04120) which specifies the method of testing required to
identify conformance to this ETS.
2 Normative references
This ETS incorporates, by dated or undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references, subsequent amendments to or revisions of any of these publications
apply to this ETS only when incorporated in it by amendment or revision. For undated references the latest
edition of the publication referred to apply.
[1] ITU-T Recommendation H.261 (1993): "Video codec for audiovisual services at
p x 64 Kbit/s".
[2] ETS 300 143: "Integrated Services Digital Network (ISDN): Audiovisual services,
Inband signalling procedures for audiovisual terminals using digital channels up
to 2 048 kbit/s".
[3] ETS 300 145: "Integrated Services Digital Network (ISDN): Audiovisual
Services; Videotelephone Systems and Terminal Equipment Operating on one
or Two 64 kbit/s Channels".
[4] CCITT Recommendation G.711 (1988): "Pulse code modulation (PCM) of voice
frequencies".
[5] CCITT Recommendation G.722 (1988): "7 kHz audio-coding within 64 kbit/s".
[6] CCITT Recommendation G.725 (1988): "System aspects for the use of the 7
kHz audio codec within 64 kbit/s".
[7] CCITT Recommendation G.728 (1992): "Coding of speech at 16 kbit/s using
low-delay code-excited linear prediction".
[8] CCITT Recommendation H.200 (1988): "Framework for recommendations for
audiovisual services".
[9] CCITT Recommendation T.50 (1992): "International Alphabet No. 5".
[10] ITU-T Recommendation T.81 (1993): "Information technology - Digital
compression and coding of continuous-tone still images - Requirements and
guidelines".

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[11] CCITT Recommendation H.221 (1992): "Frame structure for a 64 to 1 920 kbit/s
channel in audiovisual teleservices".
[12] CCITT Recommendation H.243 (1992): "Procedures for establishing
communication between three or more audiovisual terminals using digital
channels up to 2 Mbit/s".
[13] ISO/IEC 11172 (1993): "Information technology - Coding of moving pictures and
associated audio for digital storage media at up to about 1,5 Mbit/s".
[14] CCITT Recommendation T.35 (1991): "Procedure for the allocation of CCITT
defined codes for non-standard facilities".
3 Definitions
For the purposes of this ETS, the following definitions apply:
A-bit: Indicates the loss of frame or multiframe alignment.
Bit-rate allocation signal: Bit position within the frame structure to transmit, e.g. commands, control and
indication signals, capabilities.
Capability marker: The first code in a capability set.
Capability set: A sequence of capability codes started by the capability marker code.
Control and indication: End-to-end signalling between terminals consisting of control which causes a
state change in the receiver and indication which provides information as to the functioning of the system.
E-bit: Indication as to whether the most recent Cyclic Redundancy Check (CRC) block, received in the
incoming direction, contained errors or not.
ECS-channel: Optional 800 bit/s channel for use in encryption.
I-channel: The initial or only B channel, or TS1 of initial or only H0 channel, or TS1 of H11, H12 channels.
Mode: A term used to denote transmission of user information signals with a particular set of parameters.
Mode 0F: Applies only to the initial channel: there is frame structure in the Service Channel (SC), and
1)
audio is confined to the sub-channels 1 to 7 ; the audio is encoded in the same way as in CCITT
Recommendation G.711 [4] either in A-law or μ−law unless this law is also specified in brackets thus:
2)
Mode-0F(A), Mode-0F(μ), except that the Least Significant Bit (LSB) is not transmitted.
Mode 0U: Applies only to the initial channel; there is no frame structure, and audio is encoded according
3)
to CCITT Recommendation G.711 [4] , either in A-law or m−law unless this law is also specified in
brackets thus: Mode-0U(A), Mode-0U(u).
Multipoint Conference Unit: A piece of equipment located in a node of the network or in a terminal
connects several terminals and, according to certain criterions, processes audiovisual signals and
distributes them to the connected terminals.
Service Channel: The eighth sub-channel of a 64 kbit/s channel, or the seventh sub-channel when
communicating in restricted mode.

1)
When in "restricted network" operation the number of bits per audio sample is reduced by one.
2)
When in "restricted network" operation, the LSB is not the bit 8, but the bit 7.
3)
When in "restricted network" operation the number of bits per audio sample is reduced by one.

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Restricted network: A network consisting of multiples of 64 kbit/s links, but where only multiples of
56 kbit/s are usable for the terminals.
4 Symbols and abbreviations
For the purposes of this ETS, the following symbols and abbreviations apply:
BAS Bit-rate Allocation Signal
C&I Control and Indication
cap-mark capability marker
cap-set capability set
CIF Common Intermediate Format (picture format defined in ITU-T
Recommendation H.261 [1])
CRC4 Cyclic Redundancy Check 4-bit
ECS Encryption Control Signal
FAS Frame Alignment Signal
FAW Frame Alignment Word
4)
H-MLP High speed Multi Layer Protocol
H0 384 kbit/s channel
H11 1 536 kbit/s channel
H12 1 920 kbit/s channel
HSD High Speed Data
ISDN Integrated Services Digital Network
ITU-TS International Telecommunications Union - Telecommunication
Standardization Sector
LCA Loopback Command "Audio loop request"
LCD Loopback Command "Digital loop request"
LCO Loopback Command "Loop Off request"
LCV Loopback Command "Video loop request"
LSB Least Significant Bit
LSD Low Speed Data
MBE Multiple Byte Extension
MCU Multipoint Control Unit
5)
MLP Multi Layer Protocol
MSB Most Significant Bit
QCIF Quarter Common Intermediate Format (picture format defined in ITU-T
Recommendation H.261 [1])
SBE Single Byte Extension
SC Service Channel
SMF Sub-Multiframe
TEA Terminal Equipment Alarm
TS Time Slot
TS1 Time Slot 1
VCF Video Command "Freeze-picture request"
VCU Video Command "fast-Update request"

4)
MLP protocols are under discussion in the ITU-TS.
5)
MLP protocols are under discussion in the CCITT.

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5 Description
This ETS provides for dynamically subdividing an overall transmission channel of 64 kbit/s to 1 920 kbit/s
into lower rates suitable for audio, video, data and telematic purposes. The overall transmission channel is
derived by synchronising and ordering transmissions over/from 1 to 6 B-connections, from 1 to 5 H0-
connections, or an H11 or H12 connection. The first connection established is the initial connection and
carries the initial channel in each direction. The additional connections carry additional channels.
The total rate of transmitted information is called the "transfer rate"; it is possible to fix the transfer rate at
less than the capacity of the overall transmission channel (values listed in Clause 10).
A single 64 kbit/s channel is structured into octets transmitted at 8 kHz. Each bit position of the octets may
be regarded as a sub-channel of 8 kbit/s (see table 1). The eighth sub-channel is called the Service
Channel (SC), consisting of several parts as described in subclauses 5.1 to 5.4 below.
An H0, H11 or H12 channel may be regarded as consisting of a number of 64 kbit/s Time Slots (TS) (see
table 2). The lowest numbered time-slot is structured exactly as described for a single 64 kbit/s channel,
while the other TS have no such structure. In the case of multiple B or H0 channels, all channels have a
frame structure; that in the initial channel controls most functions across the overall transmission, while
the frame structure in the additional channels is used for synchronisation, channel numbering and related
controls.
The term "I-channel" is applied to the initial or only B-channel, to TS1 of initial or only H0 channel, and to
TS1 of H11, H12 channels.
Table 1: Frame structure of a single 64 kbit/s channel (B-channel)
Bit number
1 2345 67 8 (SC)
1
Octet number
S SSSS SS FAS :
u uuuu uu 8
b bbbb bb 9
- ---- -- BAS :
c cccc cc 16
h hhhh hh 17
a aaaa aa ECS :
n nnnn nn 24
n nnnn nn Sub- 25
e eeee ee chan- ·
l llll ll nel ·
# #### ## # ·
1 2345 67 8 80
5.1 Frame Alignment Signal (FAS)
This signal structures the I-channel and other framed 64 kbit/s channels into frames of 80 octets each and
multiframes of 16 frames each. Each multiframe is divided into eight 2-frame sub-multiframes. The term
"Frame Alignment Signal" (FAS) refers to the bits 1-8 of the SC in each frame. In addition to framing and
multiframing information, control and alarm information may be inserted in the FAS, as well as error check
information to monitor end-to-end error performance and to check frame alignment validity. Other time-
slots in H0, H11 or H12 connections are aligned to the first.
The bits are transmitted to line in order, bit 1 first and Octet 1 first.
FAS shall be transmitted in the Least Significant Bit (LSB) of the octet (called "bit 8") within each 125
microsecond, e.g. in an ISDN basic or primary rate interface (see also tables 1 and 2 and subclause 6.6).
It should be noted that, where interworking between the audiovisual terminal and the telephone is
required, transmission using the network timing is essential; a transmitting terminal shall always use octet
timing, if this can be obtained from the network.

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In the receiver side, FAS shall be sought in all bit positions. If the received FAS position conflicts with the
network octet timing, the FAS position is given priority. This may happen when the receiver utilises
network octet timing while the transmitter does not, as in a terminal using codecs with separate ISDN
terminal adaptor, or when interworking between 64 kbit/s and 56 kbit/s terminals takes place.
Table 2: Frame structure of higher-rate single channels (H , H , H channels)
0 11 12
125 microseconds
_______________________________________________________________________________
< >p
TS
12 3456 7 · · · · · · 6n-2 6n-1 6n
H n = 1
0
H n = 4
11
H n = 5
12
Audio + service channel
1 2345 67 8
1 Octet number
S SSSS SS FAS :
u uuuu uu 8
b bbbb bb 9
- ---- -- BAS :
c cccc cc 16
h hhhh hh 17
a aaaa aa ECS :
n nnnn nn 24
n nnnn nn
e eeee ee Sub- ·
chan-
l llll ll
nel
·
# #### ## #
1 2345 67 8 80
5.2 Bit-rate Allocation Signal (BAS)
Bits 9 to 16 of the SC in each frame are referred to as the BAS. This signal allows the transmission of
codewords to describe the capability of a terminal to structure the capacity of the channel or synchronised
multiple channels in various ways, and to command a receiver to demultiplex and make use of the
constituent signals in such structures. This signal is also used for controls and indications.
NOTE: For some countries having 56 kbit/s channels, the net available bit rates are 8 kbit/s
fewer. Interworking between a 64 kbit/s terminal and a 56 kbit/s terminal is established
according to the frame structure in subclause 6.6.
5.3 Encryption Control Signal (ECS) channel (optional)
The ECS channel is optional and can be used in single B or H0 channels as well as H11 and H12
channels, or in the initial channel of multiple-channel calls.
When switched on, the ECS channel occupies the bits 17 to 24 of the SC, a rate of 800 bit/s, and any
video or variable data channel which would otherwise occupy these bits is accordingly reduced in rate by
800 bit/s.
5.4 Remaining capacity
The remaining capacity may convey a variety of signals within the framework of a multimedia service,
under the control of the BAS. It is carried in bits 1 to 8 of each octet in the case of a single 64 kbit/s
connection, and it includes the rest of the SC. The facilities provided can be found in the list given in
subclause 8.2.

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6 Frame structure
6.1 General
An 80-octet frame length produces 80 bits in the SC. These 80 bits are numbered 1 to 80. Bits 1 to 8 of
the SC in every frame constitute the FAS (see table 3), whose content is as follows:
- multiframe structure (see subclause 6.2 and table 4a);
- Frame Alignment Word (FAW);
- A-bit;
- E-bit and C-bits (see Clause 9).
The first seven bits of the Frame Alignment Word (FAW) are formed by bits 2 to 8 of the FAS in the even
frames of a sub-multiframe. Their value is "0011011". They are complemented by a "1" in bit 2 of the
succeeding odd frame. This eighth bit of the FAW is necessary in order to avoid simulation of the FAW by
a frame-repetitive pattern elsewhere in a frame.
The A-bit of the I-channel indicates the loss of frame- or multiframe alignment. It is set to "0" whenever
frame- and multiframe is aligned (if multiframe alignment is evaluated, see subclause 6.4, otherwise only if
it is frame aligned), and is set to "1" otherwise (see subclause 6.3; for additional channels, see subclause
7.1).
When the optional Cyclic Redundancy Check 4-bit (CRC4) procedure, as defined in Clause 9, is not used,
the E-bit shall be set to 0, and bits C1, C2, C3 and C4 shall be set to 1 by the transmitter.
Table 3: Assignment of bits 1 to 8 of the service channel in each frame
Bit number 1 2 34 5 6 78
Successive frames
Even frames See subclause
0 0 1 1 0 1 1
6.2
Odd frames See subclause
1 A E C1 C2 C3 C4
6.2
FAW
6.2 Multiframe structure
The multiframe structure is shown in table 4a.
Each multiframe contains 16 consecutive frames numbered 0 to 15 divided into eight sub-multiframes of
two frames each. The multiframe alignment signal is located in bit 1 of frames 1-3-5-7-9-11 and has the
form 001011.
Bit 1 of frame 15 remains reserved ("R") for future use. The value is fixed at 0.
Bit 1 of frames 0-2-4-6 (N1 - N4) may be used for a modulo 16 counter to number multiframes in
descending order. The LSB is transmitted in frame 0, and the Most Significant Bit (MSB) in frame 6. The
receiver uses the multiframe numbering to share out the differential delay of separate connections, and to
synchronise the received signals.
The multiframe numbering shall be mandatory in both the initial and additional channels for multiple B or
multiple H0 communications, but it may or may not be inserted for single B or single H0 or H11/H12 or
other communications where synchronisation between multiple channels is not required. In this case, N1
to N4 are set to "0".
Bit 1 of frame 8 (N5) indicates whether multiframe numbering is active or inactive. It is set to 1 when
multiframes are numbered and is set to 0 when they are not.
Bit 1 of frames 10-12-13 (L1 - L3) form the channel number; the LSB is L1. This number shall be used to
number each channel in a multiconnection structure so that the distant receiver can place the octets
received in each 125 microseconds in the correct order.

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The bits N1 - N5 and L1 - L3 in the multiframe shall be considered valid, as long as they are received
consistently in three consecutive multiframes.
Bit 1 of frame 14, the Terminal Equipment Alarm (TEA) may be set to 1 in the outgoing signal, when one
or more of the following conditions holds:
- an internal terminal equipment fault exists such that it cannot receive and act on the incoming
signal;
- an internal terminal equipment fault exists such that it can no longer transmit user information in the
form previously transmitted.
Otherwise it is set to 0.
For a description of the A-bit see subclause 6.1; the use of the bits C1 to C4 and of the E-bit is described
in Clause 9.
Table 4a: Assignment of bits 1 to 8 of the SC in each frame in a multiframe
Sub- Frame Bits 1 to 8 of the service channel in every frame
multiframe
(SMF) 1 2 3 4 5 6 7 8
0N1 0 0 1 1 0 1 1
SMF1 1 0 1 A E C1C2 C3C4
2N2 0 0 1 1 0 1 1
SMF2 3 0 1 A E C1C2 C3C4
4N3 0 0 1 1 0 1 1
SMF3 5 1 1 A E C1C2 C3C4
6N4 0 0 1 1 0 1 1
Multi- SMF4 7 0 1 A E C1C2 C3C4
frame 8 N5 0 0 1 1 0 1 1
SMF5 9 1 1 A E C1C2 C3C4
10 L1 0 0 1 1 0 1 1
SMF6 11 1 1 A E C1C2 C3C4
12 L2 0 0 1 1 0 1 1
SMF7 13 L3 1 A E C1C2 C3C4
14 TEA 0 0 1 1 0 1 1
SM
...