ETSI TS 105 175-1-2 V1.1.1 (2015-04)

Access, Terminals, Transmission and Multiplexing (ATTM); Plastic Optical Fibres; Part 1: Plastic Optical Fibre System Specifications for 100 Mbit/s and 1 Gbit/s; Sub-part 2: 1 Gbit/s and 100 Mbit/s physical layer for Plastic Optical Fibres

DTS/ATTM-0239

General Information

• Status: Published
• Publication Date: 31-Mar-2015
• Technical Committee: ATTM AT2 - Infrastructure, Physical Networks & Communication Systems
• Current Stage: 12 - Completion
• Due Date: 28-Apr-2015
• Completion Date: 01-Apr-2015

Standards Content (Sample)

TECHNICAL SPECIFICATION
Access, Terminals, Transmission and Multiplexing (ATTM);
Plastic Optical Fibres;
Part 1: Plastic Optical Fibre System Specifications
for 100 Mbit/s and 1 Gbit/s;
Sub-part 2: 1 Gbit/s and 100 Mbit/s physical layer
for Plastic Optical Fibres
2 ETSI TS 105 175-1-2 V1.1.1 (2015-04)

Reference
DTS/ATTM-0239
Keywords
fibre, plastic
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3 ETSI TS 105 175-1-2 V1.1.1 (2015-04)
Contents
Intellectual Property Rights . 6
Foreword . 6
Modal verbs terminology . 6
1 Scope . 7
2 References . 7
2.1 Normative references . 7
2.2 Informative references . 7
3 Definitions and abbreviations . 7
3.1 Definitions . 7
3.2 Abbreviations . 8
4 1 Gbit/s and 100 Mbit/s data rate physical layer for plastic optical fibre . 9
4.1 Physical layer objectives . 9
4.2 Coding and Modulation Blocks (CMB) . 10
4.3 Electro Optical Interface (EO) . 11
4.4 Signalling . 11
4.5 Data Interfaces . 12
5 Coding Blocks (CMB). 12
5.1 CMB introduction. 12
5.2 CMB transmit function . 12
5.2.1 Introduction to the CMB transmit function . 12
5.2.2 Frame structure . 13
5.2.3 Payload encoding . 14
5.2.3.1 Introduction to payload encoding . 14
5.2.3.2 Data encapsulation . 14
5.2.3.3 DCRC . 18
5.2.3.4 CCRC . 19
5.2.3.5 Data packet encapsulation . 19
5.2.3.5.1 Data packet transmit encapsulation . 19
5.2.3.5.2 Rate matching . 20
5.2.3.6 Binary Scrambler . 21
5.2.3.7 Multi-Level Cosset Coding . 21
5.2.3.7.1 Introduction to Multi-Level Cosset Coding . 21
5.2.3.7.2 MLCC Demultiplexer . 23
5.2.3.7.3 BCH Encoders . 23
5.2.3.7.4 Gray mapping . 24
t
5.2.3.7.5 First Lattice transformation Λ (l)(x) . 25
5.2.3.7.6 Lattice addition . 27
t
5.2.3.7.7 Second Lattice transformation Λ (x) . 28
5.2.3.7.8 Mapping to PAM symbols . 29
5.2.3.7.9 Symbol scrambler . 29
5.2.4 Physical header encoding . 30
5.2.4.1 Introduction to physical header encoding . 30
5.2.4.2 Physical header data (PHD) . 30
5.2.4.3 Physical Header CRC16 . 33
5.2.4.4 Physical Header scrambler . 33
5.2.4.5 Physical Header BCH encoding . 33
5.2.4.6 Physical Header mapping to PAM symbols . 34
5.2.4.7 Physical Header Subframes (PHS) . 34
5.2.5 Physical pilots encoding . 34
5.2.5.1 Introduction to physical pilots . 34
5.2.5.2 S1 pilot symbols generation . 34
5.2.5.3 S2 pilot symbols generation . 35
5.2.6 Power scaling . 35
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4 ETSI TS 105 175-1-2 V1.1.1 (2015-04)
5.2.7 Tomlinson-Harashima Precoding (THP) . 36
5.3 CMB receive function . 37
5.4 PHY Control function . 38
5.4.1 Introduction to PHY control function . 38
5.4.2 Start up sequence . 38
5.4.3 Continuous tracking sequences . 40
5.4.3.1 Introduction to tracking functions . 40
5.4.3.2 THP coefficients adaptation sequence . 40
5.4.3.3 Adaptive Bit Rate sequence . 41
5.5 Link Monitor function . 43
5.6 Clock Recovery function . 43
5.7 Interface to the EO . 43
5.7.1 Introduction to the EO interface . 43
5.7.2 Signals transmitted to the EO interface . 43
5.7.3 Signals received from EO . 44
6 PHY service messages and interfaces . 44
6.1 Introduction to service interfaces . 44
6.2 Data Interface . 44
6.3 Monitor Interface . 44
6.3.1 Message description . 44
6.3.2 CMB_LINK.indication . 45
6.4 CMB Service Interface . 45
6.4.1 CMB service messages . 45
6.4.2 CMB_UNITDATA.request . 45
6.4.3 CMB_UNITDATA.indication . 45
6.4.4 CMB_DATATYPE.request . 46
6.4.5 CMB_DATATYPE.indication. 46
6.4.6 CMB_RXSTATUS.indication . 46
6.4.7 CMB_REMRXSTATUS.request . 47
6.5 EO service interface . 47
6.5.1 EO service messages . 47
6.5.2 EO_UNITDATA.request . 47
6.5.3 EO_UNITDATA.indication. 48
6.5.4 EO_TXPWR.request. 48
6.5.5 EO_RXPWR.request . 49
6.6 Connector interface . 49
7 EO interface specifications . 49
7.1 Introduction to EO interface . 49
7.2 EO interface functional specification . 49
7.2.1 Introduction to EO interface . 49
7.2.2 EO interface block diagram . 49
7.2.3 Optical transmit function . 50
7.2.4 Optical receive function . 50
7.3 Optical to fibre connector optical specification . 50
7.3.1 Introduction to the optical to fibre connector optical specification. 50
7.3.2 Transmitter optical specifications . 50
7.3.3 Receiver optical specifications . 51
7.3.4 Worst-case link budget and system margin . 51
7.3.5 Test modes . 52
7.3.5.1 Introduction to test modes . 52
7.3.5.2 Test mode 1 . 52
7.3.5.3 Test mode 2 . 52
7.3.5.4 Test mode 3 . 53
7.3.5.5 Test mode 4 . 53
7.4 Optical measurement requirements . 53
7.4.1 Introduction to optical measures . 53
7.4.2 Central wavelength measurement . 53
7.4.3 Spectral width measurement . 53
7.4.4 Extinction Ratio (ER) measurement . 54
7.4.5 Average Optical Power (AOP) measurement . 54
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5 ETSI TS 105 175-1-2 V1.1.1 (2015-04)
7.4.5 Transmit rise/fall time characteristics . 54
7.4.6 Error Vector Magnitude (EVM) measurement . 54
7.4.6.1 Introduction to EVM . 54
7.4.6.2 Reference receiver . 54
7.4.6.3 Definitions . 55
7.4.6.4 Error Vector Magnitude (EVM) . 55
7.4.6.5 Signal pattern for EVM measurement . 56
7.4.7 Transmitter timing jitter measurement . 56
7.5 Characteristics of the Plastic Optical Fibre cabling (channel) . 56
7.5.1 Duplex cable . 56
8 Fibre connector specifications (Conn). 57
8.1 Introduction to the fibre connector . 57
8.2 Connectorized duplex fibre connector . 57
8.3 Connector-less duplex fibre connector . 57
Annex A (normative): Specification for 1 000 Mbit/s over Plastic Optical Fibre . 59
A.1 Parameters specification for CMB . 59
A.2 Delay constraints . 59
A.3 EO specifications . 59
A.3.1 Transmitter optical specifications for POF link of 25 metres . 59
A.3.2 Receiver optical specifications for POF link of 25 metres . 59
A.3.3 Worst-case link budget and system margin for POF of 25 metres . 60
A.3.4 Transmitter optical specifications for POF link of 50 metres . 60
A.3.5 Receiver optical specifications for POF link of 50 metres . 60
A.3.6 Worst-case link budget and system margin for POF of 50 metres . 60
Annex B (normative): Specification for 100 Mbit/s over Plastic Optical Fibre . 62
B.1 Parameters specification for CMB . 62
B.2 Delay constraints . 62
B.3 EO interface specifications . 62
B.3.1 Transmitter optical specifications . 62
B.3.2 Receiver optical specifications for POF link of 100 metres . 63
B.3.3 Worst-case link budget and system margin for POF of 100 metres . 63
Annex C (normative): Specification for Gigabit Adaptive Bit Rate over Plastic Optical Fibre . 64
C.1 Parameters specification for CMB . 64
C.2 MLCC bit rate configurations . 64
C.3 Delay constraints . 64
C.4 EO specifications . 66
C.4.1 Transmitter optical specifications . 66
C.4.2 Receiver optical specifications . 66
C.4.3 Adaptive Bit Rate performance . 66
Annex D (normative): Specification for hundred adaptive bit rate over Plastic Optical Fibre . 67
D.1 Parameters specification for CMB . 67
D.2 MLCC bit rate configurations . 67
D.3 Delay constraints . 67
D.4 EO specifications . 68
D.4.1 Transmitter optical specifications . 68
D.4.2 Receiver optical specifications . 69
D.4.3 Adaptive Bit Rate performance . 69
History . 70
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6 ETSI TS 105 175-1-2 V1.1.1 (2015-04)
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 Access, Terminals, Transmission
and Multiplexing (ATTM).
The present document is part 1, sub-part 2 of a multi-part deliverable covering Plastic Optical Fibre, as identified
below:
Part 1: "Plastic Optical Fibre System Specifications for 100 Mbit/s and 1 Gbit/s";
Sub-part 1: "Plastic Optical Fibre System Specifications for 100 Mbit/s and 1 Gbit/s";
Sub-part 2: "1 Gbit/s and 100 Mbit/s physical layer for Plastic Optical Fibres".
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
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7 ETSI TS 105 175-1-2 V1.1.1 (2015-04)
1 Scope
The present document provides a description of an OSI physical networking layer to communicate data over plastic
optical fibre at 100 Mbit/s and 1 000 Mbit/s. A full duplex physical layer is described.
Multi data type interface is proposed, as well as its encapsulation, coding and modulation needed to achieve 1 Gbit/s
link over a bandwidth limited optical channel like the plastic optical fibre. Multiple link speeds are handled by this
physical layer.
2 References
2.1 Normative 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.
The following referenced documents are necessary for the application of the present document.
[1] IEC 60793-2-40: "Optical fibres - Part 2-40: Product specifications - Sectional specification for
category A4 multimode fibres".
[2] ANSI/EIA/TIA-455-127-1991, FOTP-127/61.1 :"Spectral Characterization of Multimode Laser
Diodes".
[3] IEC 61754-20: "Fibre optic interconnecting devices and passive components - Fibre optic
connector interfaces - Part 20: Type LC connector family".
2.2 Informative 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.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
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] ISO/IEC 11801: "Information technology - Generic cabling for customer premises".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
adaptive bit rate: capacity of PHY to adapt the bit rate as a function of the channel conditions and signal quality in
coordination with the link partner
bose, ray-chaudhurim hocquenghem: in coding theory the BCH codes form a class of parameterized error-correcting
codes, being its main advantage the ease with which they can be decoded using elegant algebraic methods
cyclic redundancy check: error detecting code designed to detect accidental changes to raw data
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8 ETSI TS 105 175-1-2 V1.1.1 (2015-04)
control cyclic redundancy check: CRC employed to check the integrity of data in PDB.CTRL blocks
data cyclic redundancy check: CRC employed to check the integrity of an encapsulated data packet and which is
included in the PDB.CTRL block signalling the end of packet
error vector magnitude: measure of the deviation between the actual signals compared to the ideal signals, commonly
defined in statistical terms
extinction ratio: ratio between the maximum and the minimum power of a given optical signal
forward error correction: technique used for controlling errors in data transmission over unreliable or noisy
communication channels
jitter: time deviations of the signal arrival from its nominal timing
link: transmission path between any two interfaces of generic cabling, see ISO/IEC 11801 [i.1]
low power idle: time periods where the Physical Layer transmission is switched off to reduce the energy consumption,
when no user data is available to transmit
multi-level cosset code: forward error correcting technique consisting on splitting the information bit stream among
several levels, for each one a binary component code is employed with an error correction capability according to the
reliability experienced by each level in data transmission over noisy channels
optical modulation amplitude: difference between the maximum and the minimum power of a given optical signal
pulse amplitude modulation: form of signal modulation where the message information is encoded in the amplitude of
a series of signal pulses
physical data block: minimum data unit of 65 bits used to encapsulate the user information received from any PHY
interface
physical control data block: special case of PDB used to carry control information between encapsulator and
de-encapsulator to identify parameters of a data packet like length or protocol, and to check the data integrity
physical idle data block: special PDB.CTRL blocks used by encapsulator for continuous transmission over the
physical communication channel when no user data are available for encapsulation received from the data interface
physical padding data block: special case of PDB.CTRL block inserted in user data encapsulation to carry out the rate
matching between the PHY interfaces and PHY bit-rate, when PHY bit-rate is greater than the interface bit-rate
physical header data: information carried by the header sub-blocks inside the frame structure and used for control and
negotiation of PHY parameters between both link ends
physical header subframe: block of 128 symbols prepended and appended by 16 zeroes that represents the minimum
transmit unit in which the PHD is divided after encoding and modulation and used to spread the PHD information along
one frame
signal to noise ratio: ratio between the average power of signal and the average power of noise in a given point
tomlinson-harashima precoding: coding technique by which the communication transmit signal pre-equalizes a
known inter-symbol interference without power penalty, providing communication signal at the output of channel
without post-cursor inter-symbol interference
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
ABR Adaptive Bit Rate
AC Alternate Current
AOP Average Optical Power
BCH bose, ray-chaudhurim hocquenghem
BER Bit Error Rate
BPSK Binary Phase Shift Keying
CCRC CRC of current PDB
CMB Physical Coding and Modulation Blocks
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9 ETSI TS 105 175-1-2 V1.1.1 (2015-04)
CRC Cyclic Redundancy Code
CW Code Word
DAC Digital to Analogue Converter
DCRC CRC of Data PDB
EO Electro Optical Interface
ER Extinction Ratio
EVM Error Vector Magnitude
FEC Forward Error Correction
FER Frame Error Rate
FS Symbol Frequency
IDLE Idle
IEC International Electrotechnical Commission
IL Insertion Losses
ISO International Organization for Standardization
IT Information Technology
LC Little Connector
LED Light Emitting
LFSR Linear Feedback Shift Register
LPI Low Power Idle
LSB Less Significant Bit
MLCC Multi Level Cosset Code
MLS Maximum Length Sequence
NMLCC Length of the MLCC code word in 1D (PAM) symbols
OFF Off state
OMA Optical Modulation Amplitude
ON On state
OSI Open Systems Interconnection
PAD Padding
PAM Pulse Amplitude Modulation
PDB Physical Data Block
PDB-ER PDB Error Rate
PHD Physical Header Data
PHS Physical Header Subframe
PHY Physical
POF Plastic Optical Fibre
PSD Power Spectral Density
QAM Quadrature Amplitude Modulation
RMS Root-Mean-Square
RX Reception
SF Scaling Factor
SNR Signal to Noise Ratio
TH Tomlinson-Harashima
THP Tomlinson-Harashima Precoder
TIA Trans Impedance Amplifier
TX Transmission
VCSEL Vertical Cavity Surface-Emitting Laser
4 1 Gbit/s and 100 Mbit/s data rate physical layer for
plastic optical fibre
4.1 Physical layer objectives
The following are the objectives of the PHY:
• Provide 1 Gbit/s and 100 Mbit/s full duplex data transmission.
• Provide speeds less than 1 Gbit/s and 100 Mbit/s with adaptive bit rate functionality if communication channel
does not provide enough capacity.
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10 ETSI TS 105 175-1-2 V1.1.1 (2015-04)
• Support operation over Plastic Optical Fibres defined in IEC 60793-2-40 [1] types A4a.2 with the parameters
specified in the respective annexes for each PHY.
-12
• Provide a Bit Error Rate (BER) less than or equal to 10 .
• Provide low power operation mode for power management.

Figure 1: Link topology
Data to be transmitted is provided to the PHY via de TX interface. The PHY generates the linear electrical signal which
is converted into optical by the light source via the driver. Optical signal is sent through the fibre and received in the
receiver of the other side of the link.
In the receiver the Photo receiver transforms the optical signal into a linear electrical signal with a trans-impedance
amplifier (TIA). The PHY transforms back this signal into the transmitted data, and provides it in the Rx interface.
Baseband PAM signalling with a modulation rate that varies with the PHY speed is used. For example, when the speed
is 1 000 Mbit/s, the symbol rate is 312,5 MSymbols/s, which results in a symbol period of 3,2 ns. The incoming bits are
mapped to PAM symbols using a three level Multi-Level Cosset Code (MLCC). In the first two levels, blocks of bits
are encoded using a Bose, Ray-Chaudhuri, Hocquenghem (BCH) code with different coding rates while in the third
level bits are not coded.
The PHY can be divided into the following parts:
• Coding and Modulation Blocks (CMB).
• Electro Optical Interface (EO).
4.2 Coding and Modulation Blocks (CMB)
The PHY CMB couples the information in the data interface, to the Electro Optical interface (EO).
The functions performed by the CMB comprise the generation of frames and the mapping of the bits in those frames to
PAM symbols using the Multi-Level Cosset Coding technique, and to send them into a Tomlinson-Harashima Precoder
(THP), which maps the PAM input into a quasi-continuous discrete time value. Then a power-scaling factor is applied
to the symbols and this THP-processed symbol stream is then passed onto a Digital to Analogue Converter (DAC).
Finally the analogue signal is sent to the EO interface.
Frames are composed of pilots, a header and data blocks, all of them of fixed length. The pilots are intended to facilitate
the receiver initialization and continuous tracking. The header is used to convey physical layer control information.
Frames are transmitted continuously to ensure that the receivers are synchronized and the equalizers are aligned to the
channel conditions. When no data is being received from the data interface, the blocks of data send the PDB.IDLE
pattern described in clause 5.2.3.2. Optionally, the Low Power Idle (LPI) mode can be used together with the
PDB.IDLE pattern to reduce energy consumption. The LPI mode is described in clause 5.2.2.
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11 ETSI TS 105 175-1-2 V1.1.1 (2015-04)
The incoming data is mapped to PAM symbols using a Multi-Level Cosset Coding technique. Depending on the
configuration, the bits are divided in up to three levels. In the first two, the incoming bits are encoded using a BCH code
while in the third level the bits are left uncoded. Then the resulting bits are mapped to PAM symbols, scrambled and
passed to the THP pre-coder and the power adaptation block.
In the transmit direction the CMB receives data packets through the data interface and constructs CMB frames that are
then mapped to PAM symbols. In the receive direction, the CMB extracts the information from the received CMB
frames and maps them to data packets on the data interface. The receiver is responsible for acquiring symbol timing and
equalizing the signal. Both linear and non-linear equalization may be used in the receiver. The reliability of the link is
ensured by the CMB Link Monitor function. The CMB PHY Control function controls the CMB operations. PHY
Control provides the start-up functions required for successful operation.

Figure 2: PHY functional block diagram
In figure 2 a block level description of the PHY is shown. Communication between different blocks is also shown.
Three different areas are clearly described: the electro optical interface (EO), the coding and modulation blocks (CMB)
and the data interface.
4.3 Electro Optical Interface (EO)
The EO specifications detail the characteristics of the optical transmitter and receiver and also of the optical cabling.
These are specific for each PHY and are defined in the annexes from A to D specifying each particular PHY.
4.4 Signalling
PHY signalling is performed by the CMB generating symbols to be transmitted on to the EO interface. The signalling
scheme achieves a number of objectives including:
a) Forward error correction (FEC) coded symbol mapping for data.
b) Uncorrelated symbols in the transmitted symbol stream.
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12 ETSI TS 105 175-1-2 V1.1.1 (2015-04)
c) Block framing and other control signals.
d) Energy Efficient operation through the use of the Low Power Idle (LPI) mode.
4.5 Data Interfaces
Several data interfaces can be implemented over the described PHY. The present document does not specify any
interface. The present document assumes data transmitted through the data interface is packet oriented vs. continuous
stream. On the other hand, there is no limitation on this aspect in the PHY description of the present document.
5 Coding Blocks (CMB)
5.1 CMB introduction
The CMB comprises two functions: CMB transmit and CMB receive.
The CMB couples the data interface to the EO interface. The CMB is defined only in abstract terms and does not imply
any particular implementation. Regardless of the implementation used, the optical specifications at the optical output
described in clause 7.2 and annexes from A to D shall be met.
The CMB comprises the following functions:
a) CMB Transmit.
b) CMB Receive.
c) PHY Control.
d) Link Monitor.
e) Clock Recovery.
The CMB Receive function receives an electrical signal from the EO and extracts the PAM symbols for the payload and
the physical header of the frame. The CMB Receive function is also in charge of equalizing the signal received from the
EO. The CMB receive function shall map incoming PAM symbols, decode and unpack the data to be sent to the data
interface.
The PHY control function controls the operation of the PHY implementing the state machines for THP coefficients
adaptation as well as the optional adaptive bit rate (ABR) to adapt the PHY rate to the channel conditions.
The Link Monitor function determines the status of the link as a function of the local and remote CMB receive status as
well as PHY control.
The Clock recovery function is in charge of recovering the transmit clock of the remote PHY from the signal received
from the EO, providing a recovered clock valid to properly s
...