EN 50090-4-2:2004

SLOVENSKI SIST EN 50090-4-2:2005

STANDARD
september 2005
Stanovanjski in stavbni elektronski sistemi (HBES) – 4-2. del: Nivoji,
neodvisni od medijev – Transportni nivo, mrežni nivo in splošni deli nivoja za
prenos podatkov za HBES razreda 1
Home and Building Electronic Systems (HBES) – Part 4-2: Media independent
layers – Transport layer, network layer and general parts of data link layer for HBES
Class 1
ICS 97.120 Referenčna številka
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

EUROPEAN STANDARD EN 50090-4-2
NORME EUROPÉENNE
EUROPÄISCHE NORM February 2004

ICS 35.100.05; 97.120 Supersedes R205-008:1996

English version
Home and Building Electronic Systems (HBES)
Part 4-2: Media independent layers -
Transport layer, network layer and general parts
of data link layer for HBES Class 1

Systèmes électroniques pour les foyers Elektrische Systemtechnik für Heim
domestiques et les bâtiments (HBES) und Gebäude (ESHG)
Partie 4-2: Couches indépendantes Teil 4-2: Medienunabhängige Schicht -
des media - Transportschicht, Vermittlungsschicht
Couches transport, réseau und allgemeine Teile
et parties générales de la couche der Sicherungsschicht für ESHG Klasse 1
données pour HBES Classe 1
This European Standard was approved by CENELEC on 2003-12-02. CENELEC members are bound to
comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in one official version (English). A version in any other language made by
translation under the responsibility of a CENELEC member into its own language and notified to the Central
Secretariat has the same status as the official version.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden,
Switzerland and United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2004 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 50090-4-2:2004 E
Contents
Foreword .3
Introduction.4
1 Scope.4
2 Normative references.4
3 Terms, definitions and abbreviations .4
3.1 Terms and definitions.4
3.2 Abbreviations.5
4 Requirements for the physical layer and independent data link layer .6
4.1 Functions of the data link layer.6
4.2 Possible media and their impact on Layer-2 .7
4.3 Data link layer services .7
4.4 Data link layer protocol .16
4.5 Parameters of Layer-2.16
4.6 Specific devices .17
5 Requirements for the network layer .17
5.1 Functions of the network layer.17
5.2 Network layer services and protocol .19
5.3 Parameters of the network layer.25
5.4 Network layer state machines.25
6 Requirements for the transport layer.29
6.1 Functionality of the transport layer .29
6.2 Transport layer Protocol Data Unit (TPDU).30
6.3 Overview communication modes .30
6.4 Transport layer services.32
6.5 Parameters of transport layer .41
6.6 State machine of connection-oriented communication mode.42
Annex A (informative) Examples of transport layer connection oriented
state machine state diagrams .54
A.1 Connect and disconnect .54
A.2 Reception of data .57
A.3 Transmission of data .59
Figure 1 – Individual address .5
Figure 2 – Group address .5
Figure 3 – Interaction of the data link layer .7
Figure 4 – Exchange of primitives for the L_Data-Service .8
Figure 5 – Frame_format Parameter .11
Figure 6 – Coding of Extended Frame Format.12
Figure 7 – Interaction of the network layer (not for Bridges or Routers).18
Figure 8 – General functionality of a router or a bridge .18
Figure 9 – Format of the NPDU (example) .19
Figure 10 – Interaction of the transport layer.29
Figure 11 – Format of the TPDU (example).30
Figure 12 – Transport control field .30
Table 1 – Usage of priority .10
Table 2 – Actions of the connection oriented state machine .44
Table 3 – Transition table – Style 1.46
Table 4 – Transition table – Style 1-rationalized.48
Table 5 – Transition table – Style 2.50
Table 6 – Transition table – Style 3.52

– 3 – EN 50090-4-2:2004
Foreword
This European Standard was prepared by the Technical Committee CENELEC TC 205, Home and
Building Electronic Systems (HBES) with the help of CENELEC co-operation partner Konnex Association
(formerly EHBESA).
The text of the draft was submitted to the Unique Acceptance Procedure and was approved by CENELEC
as EN 50090-4-2 on 2003-12-02.
This European Standard supersedes R205-008:1996.
CENELEC takes no position concerning the evidence, validity and scope of patent rights.
Konnex Association as Cooperating Partner to CENELEC confirms that to the extent that the standard
contains patents and like rights, the Konnex Association's members are willing to negotiate licenses
thereof with applicants throughout the world on fair, reasonable and non-discriminatory terms and
conditions.
Konnex Association Tel.: + 32 2 775 85 90
Neerveldstraat, 105 Fax.: + 32 2 675 50 28
Twin House e-mail: info@konnex.org
B - 1200 Brussels www.konnex.org
Attention is drawn to the possibility that some of the elements of this standard may be the subject of
patent rights other than those identified above. CENELEC shall not be held responsible for identifying any
or all such patent rights.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2004-12-01
– latest date by which the national standards conflicting 2006-12-01
with the EN have to be withdrawn (dow)
EN 50090-4-2 is part of the EN 50090 series of European Standards, which will comprise the following
parts:
Part 1: Standardisation structure
Part 2: System overview
Part 3: Aspects of application
Part 4: Media independent layers
Part 5: Media and media dependent layers
Part 6: Interfaces
Part 7: System management
Part 8: Conformity assessment of products
Part 9: Installation requirements

Introduction
This standard specifies the Media independent requirements for the data link layer and the requirements
for the network layer and the transport layer for Home and Building Electronic Systems.
This standard provides the communication stack targeted for providing the services specified in
EN 50090-3-2 “User Process” and EN 50090-4-1 “Application Layer for HBES Class 1”. It can be used as
communication stack on the physical layers as specified in EN 50090-5.
1 Scope
This part of the EN 50090 specifies the services and protocol in a physical layer independent way for the
data link layer and for the network layer and the transport layer for usage in Home and Building Electronic
Systems
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
1)
EN 50090-1 Home and Building Electronic Systems (HBES) –
Part 1: Standardisation structure
EN 50090-3-2:2004 Home and Building Electronic Systems (HBES) –
Part 3-2: Aspects of application – User process for HBES Class 1
Home and Building Electronic Systems (HBES) –
EN 50090-4-1:2004
Part 4-1: Media independent layers – Application layer for HBES Class 1
EN 50090-5 series Home and Building Electronic Systems (HBES) –
Part 5: Media and media dependent layers
ISO 7498 series Information technology - Open Systems Interconnection - Basic reference model
3 Terms, definitions and abbreviations
3.1 Terms and definitions
For the purposes of this part the terms and definitions given in EN 50090-1 and the following apply.
3.1.1
individual address
IA
unique identifier for every device in a network. The individual address is a 2-octet value that consists of
an 8-bit subnetwork address and an 8-bit device address
———————
1)
At draft stage.
– 5 – EN 50090-4-2:2004
3.1.2
sub network address
SNA
part of the individual address, consists of a 4-bit line address and a 4-bit area address, that specifies the
subnetwork in which the device is mounted
3.1.3
area address
part of the individual address that specifies the area in which the device is mounted
3.1.4
line address
part of the individual address that specifies the line in which the device is mounted
3.1.5
device address
unique identifier for every device in a subnetwork. The device address is an 8-bit value
NOTE Figure 1 shows the relationship between individual address, subnetwork address, area address, line address and device
address.
Individual Address
Octet 0 Octet 1
7 6 5 4 3 210 765 432 10
Area Line
Address Address
Device Address
Subnetwork Address
Figure 1 – Individual address
3.1.6
group address
GA
a 2-octet value
Group Address
Octet 0 Octet 1
7 6 5 432 107 654 321 0
Main Group Sub Group
Figure 2 – Group address
3.1.7
datagram
full sequence of elements (physical symbols) transporting a frame on the physical medium
3.1.8
frame
sequence of octets exchanged between data link layers through the physical layer

3.2 Abbreviations
ack Acknowledge
APDU Application layer Protocol Data Unit
con confirmation
GA Group Address
HBES Class 1 refers to simple control and command.
HBES Class 2 refers to Class 1 plus simple voice and stable picture transmission
HBES Class 3 refers to Class 2 plus complex video transfers
IA Individual Address
ind indication
iack Immediate Acknowledge
LPDU Link layer Protocol Data Unit
LSDU Link layer Service Data Unit
nack Negative Acknowledge
NPDU Network layer Protocol Data Unit
NSDU Network layer Service Data Unit
PDU Protocol Data Unit
req request
SNA Sub-Network Address
TSAP Transport layer Service Access Point
TPDU Transport layer Protocol Data Unit
UART Universal Asyn
...