1、BRITISH STANDARD BS EN 50090-4-2:2004 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 The European Standard EN 50090-4-2:2004 has the status of a British Standard ICS 35.100.05; 97.120
2、 BS EN 50090-4-2:2004 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 2 April 2004 BSI 2 April 2004 ISBN 0 580 43603 9 National foreword This British Standard is the official English language version of EN 50090-4-2:2004. The UK participation
3、 in its preparation was entrusted to Technical Committee IST/6, Data communications, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European pu
4、blications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the
5、necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the
6、interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 61 and a back cover. The BS
7、I copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEAN STANDARD EN 50090-4-2 NORME EUROPENNE EUROPISCHE NORM February 2004 CENELEC European Committee for Electrotechnical Standardization Comit Euro
8、pen de Normalisation Electrotechnique Europisches Komitee fr 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 ICS 35.100.05;
9、 97.120 Supersedes R205-008:1996English 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 Systmes lectroniques pour les foyers domestiques et les btiments (HBES) Partie 4-2: Co
10、uches indpendantes des media - Couches transport, rseau et parties gnrales de la couche donnes pour HBES Classe 1 Elektrische Systemtechnik fr Heim und Gebude (ESHG) Teil 4-2: Medienunabhngige Schicht - Transportschicht, Vermittlungsschicht und allgemeine Teile der Sicherungsschicht fr ESHG Klasse 1
11、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
12、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
13、 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, L
14、ithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 50090-4-2:2004 2 Contents Foreword 3 Introduction.4 1 Scope.4 2 Normative references.4 3 Terms, definitions and abbreviations 4 3.1 Terms and definitions4 3.2 Abb
15、reviations5 4 Requirements for the physical layer and independent data link layer 6 4.1 Functions of the data link layer6 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 Requireme
16、nts for the network layer 17 5.1 Functions of the network layer.17 5.2 Network layer services and protocol19 5.3 Parameters of the network layer25 5.4 Network layer state machines25 6 Requirements for the transport layer.29 6.1 Functionality of the transport layer 29 6.2 Transport layer Protocol Dat
17、a Unit (TPDU)30 6.3 Overview communication modes .30 6.4 Transport layer services32 6.5 Parameters of transport layer 41 6.6 State machine of connection-oriented communication mode42 Annex A (informative) Examples of transport layer connection oriented state machine state diagrams .54 A.1 Connect an
18、d disconnect .54 A.2 Reception of data.57 A.3 Transmission of data59 Figure 1 Individual address 5 Figure 2 Group address . 5 Figure 3 Interaction of the data link layer .7 Figure 4 Exchange of primitiv es for the L_Data-Service .8 Figure 5 Frame_format Parameter .11 Figure 6 Coding of Extended Fram
19、e 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 cont
20、rol field 30 Table 1 Usage of priority .10 Table 2 Actions of the connect ion oriented state machine44 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 Europe
21、an 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
22、 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
23、Konnex Associations 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: infokonnex.org B - 1200
24、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
25、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 with the EN have to be withdrawn (dow) 2006-12-01 EN 50090-4-2 is part of the EN 50090 series of Eu
26、ropean 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
27、products Part 9: Installation requirements EN 50090-4-2:2004 4 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 commu
28、nication 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 protoco
29、l 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, on
30、ly the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 50090-1 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: A
31、spects of application User process for HBES Class 1 EN 50090-4-1:2004 Home and Building Electronic Systems (HBES) 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 seri
32、es 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 eve
33、ry 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, th
34、at 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 ide
35、ntifier 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 321076543210 Area Address Line Address Subnetw
36、ork Address Device Address Figure 1 Individual address 3.1.6 group address GA a 2-octet value Group Address Octet 0 Octet 1 7 6 5 4321076543210Main 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 fra
37、me 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 EN 50090-4-2:2004 6 GA Group Address HBES Class 1 refers to simple control and command. HBES Class 2 refers to Class 1 plus
38、 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 Un
39、it 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 Asynchronous Receiver Transmitter 4 Requirements for the physical layer and independent data link layer
40、4.1 Functions of the data link layer The data link layer (also called “Layer-2“) is the layer between the data link layer user and the physical layer. The data link layer conforms to the definitions of the ISO/OSI model (ISO 7498) data link layer. It provides medium access control and logical link c
41、ontrol. The data link layer is concerned with reliable transport of single frames between two or more devices on the same subnetwork. When transmitting it is responsible for - building up a complete frame from the information passed to it by the network layer, - gaining access to the medium accordin
42、g to the particular medium access protocol in use, and - transmitting the frame to the data link layer in the peer entity or entities, using the services of the physical layer. If the transmission fails, the transmitting data link layer may decide to try again after a certain interval. In particular
43、, if the remote device signals that its buffers are temporarily full, the data link layer will wait for a pre-determined time and then attempt to re-transmit the frame (flow control). When receiving, data link layer is responsible for - determining whether the frame is intact or corrupted, - decidin
44、g after destination address check to pass the frame to upper layers, and - issuing positive or negative acknowledgements back to the transmitting data link layer. 7 EN 50090-4-2:2004 The data link layer shall provide some means to prevent from service duplication (in case of repetitions because of c
45、orrupted acknowledgement frames). The services provided include individual, group and broadcast addressing options. The data link layer uses the services of the physical layer and provides services to the data link layer user (see Figure 3). Data Link Layer Remote Layer-2 User Local Layer-2 User L_P
46、DU L_Data.req L_Data.ind Data Link Layer data service poll data service data servicelocal L-2 services L_Poll_Data.req poll data service L_Poll_Data_Update.req/con L_Busmon.ind L_ServiceInfo.ind Local Layer-2 Management Remote Layer-2 Management L_Poll_Data.con L_Data.con L_SystemBroadcast.req L_Sys
47、temBroadcast.con L_SystemBroadcast.indFigure 3 Interaction of the data link layer 4.2 Possible media and their impact on Layer-2 The data link layer is defined for the following media: Twisted Pair 0; Twisted Pair 1; Powerline 110; Powerline 132; Radio Frequency. Data link layer will also be defined
48、 for the following media: Infra-red; Ethernet. The data link layer is open for new media in the future. Each medium needs a dedicated medium access control and a logical link control that adapts to the medium access control. This clause focuses on medium independent features, this is, mainly on the
49、provided service interface to network layer. The physical layer dependent requirements are specified in EN 50090-5. 4.3 Data link layer services 4.3.1 Data link layer modes The data link layer mode defines which data link layer services shall be available to the data link layer user. There shall be 2 data link layer modes: a) the normal mode; b) the busmonitor mode.
