ETSI ETS 300 463 ed.1 (1996-09)

SLOVENSKI STANDARD
01-december-2003
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Transmission and Multiplexing (TM); Requirements of passive Optical Access Networks
(OANs) to provide services up to 2 Mbit/s bearer capacity
Ta slovenski standard je istoveten z: ETS 300 463 Edition 1
ICS:
33.040.20 Prenosni sistem Transmission systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN ETS 300 463
TELECOMMUNICATION September 1996
STANDARD
Source: ETSI TC-TM Reference: DE/TM-03019
ICS: 33.080
Key words: Access, bearer, network, optical, transmission
Transmission and Multiplexing (TM);
Requirements of passive Optical Access Networks (OANs) to
provide services up to 2 Mbit/s bearer capacity
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
Postal address: F-06921 Sophia Antipolis CEDEX - FRANCE
Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
X.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: secretariat@etsi.fr
Tel.: +33 92 94 42 00 - Fax: +33 93 65 47 16
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 1996. All rights reserved.

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ETS 300 463: September 1996
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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ETS 300 463: September 1996
Contents
Foreword .5
1 Scope .7
2 Normative references.7
3 Definitions and abbreviations .9
3.1 Definitions .9
3.2 Abbreviations .10
4 Configuration of an OAN .11
4.1 Topological and functional issues.11
4.2 Service capability .14
5 ONU .14
5.1 Description of functions .14
5.1.1 ONU core shell.15
5.1.2 ONU service shell.15
5.1.3 ONU common shell .15
5.2 ONU dimensions.16
5.3 User to Network Interfaces (UNIs).17
5.4 ONU power considerations.17
6 ODN .18
6.1 General ODN requirements.18
6.2 Reach limitations and split ratios of the ODN .18
7 OLT .19
7.1 Description of functions .19
7.1.1 OLT core shell.20
7.1.2 OLT service shell.21
7.1.3 OLT common shell.21
7.2 OLT dimensions.21
7.3 SNIs .22
8 Specific attributes of OANs .22
8.1 Transmission method .22
8.2 Operating wavelength range for an OAN.22
8.2.1 SDM .23
8.2.2 TCM.23
8.2.3 WDM .23
8.2.4 FDM.23
8.3 Signal transfer delay .23
9 Timing and synchronization.24
9.1 Synchronization architecture.24
9.2 Protection and ONU timing .25
9.3 Synchronization interfaces.25
9.3.1 Jitter and wander tolerance .25
9.4 Network side interfaces for synchronous services.25
9.4.1 Jitter and wander tolerance .25
9.4.2 Jitter and wander generation.25
9.5 User side interfaces for synchronous services .26
9.5.1 Jitter and wander tolerance .26
9.5.2 Jitter and wander generation.26
9.6 Timing requirements for asynchronous services .26

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ETS 300 463: September 1996
10 OAM. 26
10.1 General OAM requirements . 26
10.2 Line configuration and testing . 27
10.3 OAN operation. 27
11 Security of OANs . 28
11.1 General information. 28
11.2 Identification and authentication. 29
11.3 Access control. 29
11.4 Accountability and audit. 29
11.5 Accuracy. 29
11.6 Availability. 29
11.7 Data exchange . 30
11.8 Layers of physical security . 30
11.8.1 Physical security function. 30
11.8.2 Transmission system security function. 31
11.8.3 Service security function. 31
12 Safety. 31
13 Reliability and availability . 31
14 Upgrade of OANs . 32
14.1 ODN considerations . 32
14.2 ONU considerations . 33
Annex A (informative): Relationship between types and classes for ONUs. 34
Annex B (informative): An example power consumption for an OAN. 35
Annex C (informative): Signal transfer delay measurement technique . 37
Annex D (informative): Framework to capture the OAM requirements . 38
D.1 Analysis of OAM requirements by functional sub-systems. 38
D.2 Examples for line circuit supervision . 39
D.3 Analysis of OAM requirements by functional category . 40
D.3.1 Access and security . 40
D.3.2 Configuration and resource management. 40
D.3.3 Performance management . 41
D.3.4 Event (alarm) management. 41
D.3.5 Financial accounting management . 42
Annex E (informative): Bibliography . 43
History. 44

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ETS 300 463: September 1996
Foreword
This European Telecommunication Standard (ETS) has been produced by the Transmission and
Multiplexing (TM) Technical Committee of the European Telecommunications Standards Institute (ETSI).
This ETS describes cost effective and flexible access networks using optical fibre technology and is
designed to provide both services to meet the current demands and an infrastructure which is able to
satisfy the requirements of the future.
Transposition dates
Date of adoption of this ETS: 16 August 1996
Date of latest announcement of this ETS (doa): 31 December 1996
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 30 June 1997
Date of withdrawal of any conflicting National Standard (dow): 30 June 1997

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ETS 300 463: September 1996
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ETS 300 463: September 1996
1 Scope
This European Telecommunication Standard (ETS) describes cost effective and flexible access networks
using optical fibre technology. This ETS is designed to provide both services to meet the current demands
and an infrastructure which is able to satisfy the requirements of the future.
This ETS describes the characteristics of an Optical Access Network (OAN) with the capability of
transporting interactive services, based on 64 kbit/s bearer capabilities, between the User Network
Interface (UNI) and the local exchange. The ETS considers an OAN capable of providing business and
residential customers with a range of services (up to 2 Mbit/s) over a passive split optical network.
Distributive services (e.g. cable television) are outside the scope of this ETS.
The OAN described in this standard has considered the requirement for the access network to adapt to
the changing requirements of individual customers in terms of capacity, flexibility and types of services
offered without the need for network operators to provide service specific overlay networks.
The considered systems within this ETS are based on Time Division Multiple Access (TDMA) and/or
Subcarrier Multiple Access (SCMA) methods. One and two fibre systems are described.
This ETS considers OANs where the Optical Distribution Network (ODN) is based on point-to-multipoint
tree and branch options as described in ETS 300 681 [5].
This ETS is not a complete system definition. It identifies aspects that can be defined without preventing
transmission innovation.
2 Normative references
This ETS incorporates by dated and 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 applies.
[1] EC SYN 287 (1990): "Proposal for the council directive concerning the
protection of individuals in relation to the processing of personal data".
[2] EC SYN 288 (1990): "Proposal for the directive concerning the protection of
personal data and privacy in the context of public digital telecommunication
networks, in particular the integrated services digital network (ISDN) and public
digital mobile networks".
[3] EN 41 003: "Particular safety requirements for equipment to be connected to
telecommunication networks".
[4] EN 60 950: "Safety of information technology equipment, including electrical
business equipment".
[5] prETS 300 681 (1996): "Transmission and Multiplexing (TM); Optical distribution
network for Optical Access Networks (OANs)".
[6] prETS 300 736: "Transmission and Multiplexing (TM); Operation and
maintenance of Optical Access Networks (OANs)".
[7] ETR 080: "Transmission and Multiplexing (TM); Integrated Services Digital
Network (ISDN) basic rate access; Digital transmission system on metallic local
lines".
[8] ETS 300 011: "Integrated Services Digital Network (ISDN); Primary rate user-
network interface; Layer 1 specification and test principles".
[9] ETS 300 012: "Integrated Services Digital Network (ISDN); Basic user-network
interface; Layer 1 specification and test principles".

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ETS 300 463: September 1996
[10] ETS 300 019: "Equipment Engineering (EE); Environmental conditions and
environmental tests for telecommunications equipment".
[11] ETS 300 233: "Integrated Services Digital Network (ISDN); Access digital
section for ISDN primary rate".
[12] ETS 300 288: "Business TeleCommunications (BTC); 64 kbit/s digital
unrestricted leased line with octet integrity (D64U); Network interface
presentation".
[13] ETS 300 324: "Signalling Protocols and Switching (SPS); V interfaces at the
digital Local Exchange (LE); V5.1 interface for the support of Access Network
(AN)".
[14] ETS 300 347: "Signalling Protocols and Switching (SPS); V interfaces at the
digital Local Exchange (LE); V5.2 interface for the support of Access Network
(AN)".
[15] ETS 300 376-1: "Signalling Protocols and Switching (SPS); Q3 interface at the
Access Network (AN) for configuration management of V5 interfaces and
associated user ports; Part 1: Q3 interface specification".
[16] ETS 300 378-1: "Signalling Protocols and Switching (SPS); Q3 interface at the
Access Network (AN) for fault and performance management of V5 interfaces
and associated user ports; Part 1: Q3 interface specification".
[17] ETS 300 462-2: "Transmission and Multiplexing (TM); Generic requirements for
synchronization networks; Part 2: Synchronization network architecture".
[18] ETS 300 462-5: "Transmission and Multiplexing (TM); Generic requirements for
synchronization networks; Part 5: Timing characteristics of slave clocks suitable
for operation in Synchronous Digital Hierarchy (SDH) equipment".
[19] ETS 300 418: "Business TeleCommunications (BTC); 2 048 kbit/s digital
unstructured and structured leased lines (D2048U and D2048S); Network
interface presentation".
[20] ITU-T Recommendation G.703: "Physical/electrical characteristics of
hierarchical digital interfaces".
[21] ITU-T Recommendation G.704: "Synchronous frame structures used at
1 544, 6 312, 2 048, 8 488 and 44 736 kbit/s hierarchical levels".
[22] ITU-T Recommendation G.803: "Architectures of transport networks based on
the synchronous digital hierarchy (SDH)".
[23] ITU-T Recommendation G.823: "The control of jitter and wander within digital
networks which are based on the 2 048 kbit/s hierarchy".
[24] ITU-T Recommendation G.832: "Transport of SDH elements on PDH networks:
Frame and multiplexing structures".
[25] ITU-T Recommendation I.430: "Basic user-network interface - Layer 1
specification".
[26] ITU-T Recommendation M.3010: "Principles for a telecommunications
management network".
[27] EC ITSEC: "Information Technology Security Criteria (ITSEC)".

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ETS 300 463: September 1996
3 Definitions and abbreviations
3.1 Definitions
For the purposes of this ETS, the following definitions apply:
access link: The whole of transmission means between a given network interface and a single user
interface. The concept of access link is used in order to allow a functional and procedural description and
a definition of the network requirements.
NOTE 1: The user-side and the network-side of the access link are not identical and therefore
the access link is not symmetrical.
Adaptation Unit (AU): An AU provides adaptation functions between the Optical Network Unit (ONU) and
the user side.
diplex working: Bidirectional communication using a different wavelength for each direction of
transmission over a single fibre.
duplex working: Bidirectional communication using the same wavelength for both directions of
transmission over a single fibre.
Field Replaceable Unit (FRU): A FRU is the lowest level of maintenance spare and will typically be a
plug-in card. The modules of an Optical Line Termination (OLT) and ONU should be FRUs.
full access: Given no other connections, any slot on one side of the concentrator may be connected to
any slot on the other side of the concentrator.
multiplexing; static: A system of multiplexing where the relationship between the position of the
tributaries to the multiplexed format (channels) is predetermined and fixed.
multiplexing; dynamic: A system of multiplexing where the relationship between the position of the
tributaries to the multiplexed format (channels) is flexible. It also allows for tributaries to be aggregated
where there are more tributaries than available channels and the possibility to vary the bandwidth to n
times the capacity of the channels.
non-blocking: Any allowable connection may be made at any time, regardless of the order in which
connections are established or removed. (An allowable connection assumes that the respective slots are
free).
Optical Access Network (OAN): The set of access links sharing the same network-side interfaces and
supported by optical access transmission systems.
NOTE 2: The OAN may include a number of ODNs connected to the same OLT.
Optical Distribution Network (ODN): An ODN provides the optical transmission means from the OLT
towards the users, and vice versa.
Optical Line Termination (OLT): An OLT provides the network-side interface of the OAN and is
connected to one or more ODNs.
Optical Network Unit (ONU): An ONU provides (directly or remotely) the user-side interface of the OAN
and is connected to the ODN.
optical filter: A device for the selection of optical signals at optical specific wavelengths.
optical power splitter: A device that has n inputs with k outputs, where n = 1 to k and k 2.
passive component: A component part of the ODN that does not require external power, i.e. fibre,
splitter, filter.
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ETS 300 463: September 1996
point-to-multipoint: A transmission system which can have one input or output at one end with multiple
inputs or outputs at the other end.
Passive Optical Network (PON): A PON is a subset of an ODN and refers to a point-to-multipoint option.
Space Division Multiplexing (SDM): Bi-directional multiplexing using different fibres for up and
downstream signals.
Sub Carrier Multiplexing (SCM): Multiplexing multiple electrical frequencies onto a single fibre at a
single wavelength to provide an individual frequency to each multipoint to point path.
serial number: A reference number assigned to an object, component, etc.
service channel: Each bearer service is allocated a service channel in the PON systems. e.g. a 64 kbit/s
channel to support the Public Switched Telephone Network (PSTN).
Service Unit (SU): A FRU that supports service interface (Service Unit (SU)) function(s).
simplex working: Communication which uses a different fibre for each direction of transmission.
Time Compression Multiplexing (TCM): Bi-directional multiplexing using different time slots for up and
downstream signals.
Time Division Multiplexing (TDM): Multiplexing information onto fixed time ranges.
Tributary Unit (TU): A TU is a FRU with one or more tributary interface functions.
Wavelength Division Multiplexing (WDM): Bi-directional multiplexing using different optical wavelength
for up and downstream signals.
3.2 Abbreviations
For the purposes of this ETS, the following abbreviations apply:
AC Alternating Current
A/D Analogue to Digital (conversion)
AN Access Network
ATM Asynchronous Transfer Mode
AU Adaptation Unit
BA Basic Access
B-ISDN Broadband Integrated Services Digital Network
DC Direct Current
D/A Digital to Analogue (conversion)
D2048S 2 048 kbit/s digital structured ONP leased line
D2048U 2 048 kbit/s digital unstructured ONP leased line
FDM Frequency Division Multiplexing
FITL Fibre In The Loop
FRU Field Replaceable Unit
ISDN Integrated Services Digital Network
ISDN-BA ISDN-Basic Access
ITSEC Information Technology Security Criteria
MTBF Mean Time Between Failures
MTTR Mean Time To Repair
NNI Network to Network Interface
NT Network Termination
NTI Network Termination 1
OAM Operations Administration and Maintenance
OAN Optical Access Network
ODN Optical Distribution Network
OLT Optical Line Termination
ONP Open Network Provision
ONU Optical Network Unit
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ETS 300 463: September 1996
OS Operations System
OSI Open Systems Interconnection
OTDR Optical Time Domain Reflectometer
PON Passive Optical Network
POTS Plain Old Telephony Services
ppm parts per million
PRA Primary Rate Access
PRC Primary Reference Clock
PSTN Public Switched Telephone Network
Q Q interface for the Access Network
AN
SCM Sub Carrier Multiplexing
SCMA Sub Carrier Multiple Access
SDH Synchronous Digital Hierarchy
SDM Space Division Multiplexing
SELV Subscriber Extra Low Voltage
SNI Service Node Interface
SPF Signalling Processing Function
SSU Synchronization Supply Unit
SU Service Unit
TCM Time Compression Multiplexing
TDM Time Division Multiplexing
TDMA Time Division Multiple Access
TNV Telecom Network Voltage
TU Tributary Unit
UIpp Unit Intervals peak to peak
UNI User Network Interface
VC Virtual Container
VF Voice Frequency
WDM Wavelength Division Multiplexing
4 Configuration of an OAN
The configuration of an OAN is considered in this clause. It provides an introduction to the detailed
requirements of an OAN.
NOTE: The functional architecture issues are under study in ETSI Sub Technical Committee
(STC) TM3.
4.1 Topological and functional issues
A configuration for an OAN is shown in figure 1. An OAN consists of:
a) one OLT;
b) at least one ODN;
c) at least one ONU;
d) AUs.
The ODN provides the optical transmission means from the OLT towards the users and vice versa. ONUs
provide the user-side interface of the OAN and are connected to the ODN. The functions comprised by the
AU include adaptation of the service interfacing between ONU and user (e.g. conversion of data
communication protocols and rates) as well as transportation of the service over the last drop between the
ONU and user when these interfaces do not coincide (e.g. Network Termination 1 (NT1) for Integrated
Services Digital Network, Basic Access (ISDN-BA)).
The reference points User Network Interface (UNI) and Service Node Interface (SNI) as well as the Q3
interface shown in figure 1. The R and S reference points are described in ETS 300 681 [5].
NOTE: Standardization work related to such an AU is outside the scope of this ETS.

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ETS 300 463: September 1996
Q
AN System Management
ONU
AU
Line
User
Network
side
ODN
OLT
side
ONU
UNI S/R S/R
SNI
Access link
Figure 1: Example configuration for an OAN
A functional architecture of the OAN in accordance with the principles of ITU-T Recommendation
G.803 [22] is shown in figure 2. ISDN-BA is the adapted service shown in this architecture. The Service
Node Interface (SNI) is according to V5.1, see ETS 300 324 [13]. The multiplexing of the user individual
D-channels is performed on a higher layer and not shown in this structure. The structure of D and D* are
not identical. Although a number of other options exist (e.g. leased lines, V5.2, etc.) they are not shown on
this diagram.
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ETS 300 463: September 1996
Figure 2: Example architecture configuration for the OAN
Transm ission path
layer
B
D D*
Coded ringing, hook (+dial)
Payload/ODN
on transm ission
Adaptation Adaptati
Adaptation
into POTS protocol
into ISDN
termination
Adaptations of
adaptation
line
BA line
ISDN BA and POTS
into G.704 (for V5.1)
O DN transmission protocol trail
Transm ission section
layer
ODN
Copper
transmission
line prot
ocol
T TP
Adaptation
termination
(NT1)
E/O Adaptation
ISDN BA
POTS line
Optical section trail
termination termination
G.702 termination
Optical term ination
POT S line W avelength 1
S/T bus G.704 connection (V5.1)
S/T bus
O ptical layer
W avelength n
Fibre adaptation
Fibre termination
Medium layer
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ETS 300 463: September 1996
4.2 Service capability
The OAN shall be capable of supporting the following services:
a) POTS;
b) leased lines;
c) packet data;
d) ISDN-BA;
e) ISDN Primary Rate Access (ISDN-PRA);
f) n x 64 kbit/s;
g) 2 Mbit/s (structured or unstructured).
5 ONU
The ONU provides an optical interface towards the ODN and implements the interfaces at the customer
side of the OAN. ONUs shall be located on the customer's premises (fibre to the home, fibre to the office,
fibre to the building) or in the field as part of the optical access section (fibre to the kerb). The ONU
provides the means necessary for delivering the different services that are to be handled by the system.
5.1 Description of functions
Figure 3 shows a functional description of the ONU. It is useful for standardization purposes to consider
the ONU in terms of three parts, these are defined as:
a) core shell;
b) service shell;
c) common shell.
The functionality of these shells is described in subclauses 5.1.1 to 5.1.3.
Service shell
Core shell
Service
interface
Customer
function
Transmission
Customer and
O DN
m ultiplex
services
* interface
function
*
function ODN
M ultiplex
*
function
*
Service
interface
function
Pow er supply
OAM
function
fu nction
Common shell
Figure 3: ONU functional blocks

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ETS 300 463: September 1996
5.1.1 ONU core shell
The ONU core shell includes:
a) ODN interface;
b) transmission multiplexing;
c) customer and service multiplexing functions.
The ODN interface function provides a set of optical physical interface functions terminating the relevant
set of optical fibres of the ODN, and includes optical/electrical and electrical/optical conversion.
The transmission multiplexing function provides the necessary functions for evaluation and allocation of
the incoming and outgoing signals from and to the ODN Interface Function extracting and inputting the
information relevant to this ONU.
The customer and service multiplexer function assembles/disassembles the information from/to the
different subscribers and connects the individual service interface functions.
5.1.2 ONU service shell
The ONU service shell provides the service interface functions.
The service interface functions provide the customer service interfaces and their adaptation into 64 kbit/s
or n x 64 kbit/s. The function can be provided for a single customer or a group of customers. It also
provides signalling conversion functions according to the physical interface (e.g. ringing, signalling,
Analogue to Digital (A/D) and Digital to Analogue (D/A) conversions).
5.1.3 ONU common shell
The ONU common shell includes power supply and Operations Administration and Maintenance (OAM)
functions.
The power supply function provides the powering to the ONU (e.g. Alternating Current (AC) to
Direct Current (DC) or DC to DC conversion).
Power shall be provided locally (from mains) or remotely. The power supply may be shared by several
ONUs. The ONU shall be capable of operating via a battery back-up source.
The OAM function provides the means to handle the OAM functionality to all blocks of the ONU (e.g.
control of loop backs in the different blocks).
NOTE: For local control an interface may be provided for testing purposes.

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ETS 300 463: September 1996
5.2 ONU dimensions
The ONU dimensions considered in this subclause refer to issues relating to the service capacity.
An ONU is defined as being of a specific type and belonging to a specific class.
Five types and three classes are described. The types are described in terms of number of POTS circuits
which can be provided and are shown in table 1:
Table 1: ONU type description
Maximum number of POTS circuits
that can be equipped
Type I 4 POTS
Type II 12 POTS
Type III 30 POTS
Type IV 60 POTS
Type V 120 POTS
The classes of ONU are defined by the maximum throughput required at the customer side of the ONU.
This is defined in terms of the usable B channels (where B is a 64 kbit/s bearer channel). Control and
signalling channels are not generally included except where carried within the bearer channels (e.g. ISDN
Primary Rate Access (ISDN PRA)).
Three classes are defined as shown in table 2:
Table 2: ONU Class description
Maximum number of B channels
Class 1 4B
Class 2 32B
Class 3 64B
ONU types and classes above and below the values described in tables 1 and 2 have not been defined
and are for further study.
It shall be possible to reallocate unused B channels from one ONU to any other ONU up to their maximum
capacity. For example: a class 3 ONU has a maximum throughput of 64 B. If only 30 POTS lines are
required then 34 B can be reallocated to other ONUs.
It shall be possible to mix different ONU types and classes on the same ODN.
The relationships between types and classes are described in annex A.
To calculate the above service capacities the following equivalents shall be used:
1 x 64 kbit/s:
= 1 analogue telephone access (POTS);
= 1 analogue customer access for fixed connections (leased line);
= 1 digital customer access for fixed connections 64 kbit/s (leased line);
= 1 data access < 64 kbit/s;
= 1/2 ISDN-BA;
= 1/32 ISDN-PRA;
= 1/32 digital customer access for fixed connections 1,984 Mbit/s (leased line);
= 1/32 digital customer access for fixed connections 2,048 Mbit/s (unstructured leased line).

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ETS 300 463: September 1996
The SUs of the ONUs as an example may be equipped as follows: 2 analogue telephone accesses
(POTS) per card; 2 analogue fixed accesses (leased lines) per card; 2 digital fixed accesses 64 kbit/s
(leased lines) per card; 1 ISDN-BA (T interface) per card; 1 ISDN-BA (Line interface) per card; 1
ISDN-PRA per card and 1 digital fixed access 2 Mbit/s (leased line) per card.
5.3 User to Network Interfaces (UNIs)
The narrow band ISDN and POTS interfaces have been identified and the existing UNIs shall be used:
analogue telephony services: national;
analogue leased line services: national;
ISDN-BA: ETS 300 012 [9]: for ISDN BA, this also could be a line interface,
where the NT is connected to the ONU using a transmission
system according to ETR 080 [7];
ISDN-PRA: ETS 300 011 [8];
circuit switched and packet data the customer interface for data services should be 64 kbit/s
services: according to ITU-T Recommendation G.703 [20]; or 2 Mbit/s
according to ITU-T Recommendations G.703 [20] and
G.704 [21];
NOTE 1: The conversion to the appropriate data network interface may be provided by an AU
which is not part of the OAN. In case the ONU is not located at the customers
premises, an AU as part of the OAN is also needed to facilitate the transport of this
64 kbit/s bearer channel made available at the interface of the SU concerned.
digital leased line services:
64 kbit/s ITU-T Recommendation G.703 [20]: ETS 300 288 [12];
64 kbit/s ITU-T Recommendation I.430 [25]: similar to ETS 300 012 [9];
1 984 kbit/s: ETS 300 418 [19] (D2048S);
2 048 kbit/s: ETS 300 418 [19] (D2048U);
n x 64 kbit/s (n < 30): ETS 300 418 [19] (D2048U).
For the unstructured 2,048 Mbit/s:
In the case when a Synchronous Digital Hierarchy Virtual Container 12 (SDH VC12) path is used this shall
be terminated in the ONU. A justification mechanism has to be used to provide the possibility of third party
timing.
NOTE 2: The transport of the SDH VC12 and the related timing does not require
standardization.
A method similar to the ITU-T Recommendation G.832 [24] can be used in 2,048 Mbit/s oriented
networks. Another possibility is the transport of the complete SDH TU12 including pointers in a OAN
providing a flexible transmission frame.
5.4 ONU power considerations
For each ONU type the minimum, maximum and typical power requirements and the conditions used to
calculate them shall be provided. The specific powering requirements of the different interfaces (as
defined in subclause 5.3) shall be considered.
Power used for battery charging should not be included in the core power consumption values, however,
this power parameter shall be provided.

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ETS 300 463: September 1996
The loop resistance up to the network termination point is dependant on the national implementation,
300 Ω should be used for calculation purposes.
The powering requirements calculation for an ONU shall take into account the environmental class
described in ETS 300 019 [10].
A detailed description of the powering aspects of ONUs and examples of power consumption values are
shown in annex B.
6 ODN
The detailed specification of the ODN is considered in ETS 300 681 [5].
6.1 General ODN requirements
The ODN is based on point-to-multipoint tree and branch options as described in ETS 300 681 [5].
The ODN includes no optical to electrical conversion.
ODN optical elements may be co-located with the ONU and/or OLT.
The ODN shall support operation in the second and third wavelength regions as described in
ETS 300 681 [5].
6.2 Reach limitations and split ratios of the ODN
In this subclause all distances quoted refer to fibre kilometres. The OAN system shall be able to operate
over a distance up to 20 km.
Two OAN system types are described which are based on the transmission methods considered in
clause 8. OAN systems type 2 have restricted ODN requirements e.g. Time Compression Multiplexing
(TCM).
At the given distances in table 3 the split ratios shown are required.
Table 3: OAN system types
Distance OAN system type 1 OAN system type 2
(e.g. SDM, WDM, FDM) (e.g. TCM)
20 km A split ratio of at least 16 way shall be A split ratio of at least 8 way shall be
supported supported
10 km A split ratio of at least 32 way shall be A split ratio of at least 16 way shall be
supported supported
SDM: Space Division Multiplexing
WDM: Wavelength Division Multiplexing
FDM: Frequency Division Multiplexing
The path losses for the above requirements are calculated in ETS 300 681 [5].

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ETS 300 463: September 1996
There is a OAN system requirement to operate with a differential fibre distance (Δ) between the nearest
and furthest ONU from the OLT as defined in figure 4.
ONU 1
x1
OLT
x2
ONU n
x1: Shortest distance between OLT and ONU of an ODN.
x2: Longest distance between OLT and ONU of an ODN.
Figure 4: Reach limitations of PONs
The differential fibre distance (Δ) = x2 - x1
The OAN system must be capable of operating over an ODN such that the differential fibre distance (Δ)
between the nearest and furthest ONU from the OLT is anywhere between 0 km and at least 5 km.
NOTE: If the OAN system will not provide service to ONUs when the distance between the
nearest and furthest ONU from the OLT is 4,5 km then the system does not meet this
requirement. However if the OAN system will provide service to ONUs when the
distance between the OLT and the nearest and furthest ONU is 5,1 km, 10 km or
20 km (i.e. greater than or equal to 5 km) then the system meets the requirement).
7 OLT
The OLT provides at least one optical interface towards the ODN and provides at least one network
interface on the network side of the OAN. The OLT can be co-located within a local exchange or at a
remote location. It comprises the means necessary for delivering different services to the required ONUs.
7.1 Description of functions
Figure 5 shows a functional description of the OLT. It is useful for standardization purposes to consider
the OLT in terms of three parts, these are defined as:
a) core shell;
b) service shell;
c) common shell.
The functionality of these shells is described in subclauses 7.1.1 to 7.1.3.

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ETS 300 463: September 1996
Service shell
Core shell
ODN
interface
Tributary
function
interface
function
*
Digital
Transmission
cross
*
m ultiplex
ODN *
connect
function
Network
function
*
*
ODN
*
interface
function
Tributary
interface
fu nction
Common shell
Pow er supply
OAM
SPF
function
function
To m ediation function
and then Q3 interface
SPF: Signalling Processing Function
Figure 5: OLT functional blocks
7.1.1 OLT core shell
The OLT core shell includes:
a) ODN interface;
b) transmission multiplexing;
c) customer and service cross connect functions.
The ODN interface function provides a set of physical optical interface functions terminating the relevant
set(s) of optical fibres of the ODN(s), and includes optical/electrical and electrical/optical conversion.
In order to enable implementation of protection switching between geographically redundant routes up to a
flexibility point in the ODN where optical fibre splitting occurs, the OAN system should provide the
possibility of optionally equipping the OLT with a duplicate ODN interface. This is in addition to the
maximum number of ODNs that the OLT is designed for normal operation.
Detailed characteristics of possible protection mechanisms are not considered in this ETS.
The transmission multiplexing function provides the necessary functions for transmitting or receiving
service channels over the ODN.
The customer and service cross connect function provides connectivity between the available bandwidth
at the ODN side and the network parts at the network side.
Full access shall be provided.

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ETS 300 463: September 1996
7.1.2 OLT service shell
The OLT service shell can include NT interface and signal processing functions.
A TU is an FRU with one or more tributary interface functions.
A network tributary interface function is a 2 Mbit/s port (described in subclause 7.3) on a TU, it provides
the interface between the OLT and the main network. They shall be specific to a single service,
configurable to one of a number of services, or capable of simultaneously supporting two or more different
services.
Any TU that provides two or more 2 Mbit/s ports shall be independently configurable on a per port basis.
For this type of multi-port TU, it shall be possible to configure each port to a different service.
Each TU position in the OLT equipment shall be capable of accepting a TU of any type.
The OLT shall be able to support any number of TUs up to the designed maximum number in any
combination of services.
The signal processing functions provide the means for handling signalling information through the OLT.
7.1.3 OLT common shell
The OLT common shell can include power supply and OAM functions.
The power supply function converts an external power source to the required level.
The OAM function provides the means to handle the OAM functionality to all blocks of the OLT.
It also provides an interface function both for local control for testing purposes and for the Q interface for
the Access Network (Q ) interface towards the Operations System (OS) via a mediation function.
AN
7.2 OLT dimensions
The OLT dimensions considered in this subclause refer to issues relating to the service capacity.
The OLT dimensions are described in table 4. Two OAN system types are described which are based on
the trans
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