developed for ENERGA-Operator SA
Version: 0.03
Date: 2011-07-31
Contents
1 Glossary of terms and acronyms 5
2 Introduction 8
3 Concept for the communication standard in DSO 9
3.1 Assumptions for the communication standard 9
3.1.1 General assumptions 9
3.1.2 Technical assumptions 9
3.2 Overall concept of the communication standard 10
3.2.1 Area of communication between SAK and concentrators 11
3.2.2 Area of communication between concentrators and meters 11
3.2.3 Area of communication between SAK and meters 12
3.2.4 Traffic prioritization 13
3.2.5 Digital signatures 17
3.2.6 Concept of transport 17
4 Meter Use Cases 20
4.1 Categories, Identifiers and Statuses of Meter Use Cases 20
4.2 List of Meter Use Cases 21
4.3 Analysis of Meter Use Cases 21
4.3.1 Installation Category 23
4.3.2 Configuration Category 30
4.3.3 Readouts Category 34
4.3.4 Control Category 38
4.3.5 Reporting Category 43
5 DCSML communication protocol 45
5.1 Description of Messages 45
5.2 Protocol Grammar 45
5.2.1 Basic definitions of SML data structures 46
5.2.2 Basic structures of DCSML data 53
5.2.3 DCSML Functions – associated with the operation of a concentrator 55
5.2.4 DCSML functions – associated with the operation of a meter 57
6 Examples of queries and responses in DCSML (in APDU and source forms) 61
6.1 ASN.1 definition 61
6.2 Examples 63
6.2.1 Example 1-1-1 63
6.2.2 Example 1-1-4 65
6.2.3 Example 1-5-1 67
6.2.4 Example 1-5-4 69
6.2.5 Example 5-1-1 71
6.2.6 Example 5-1-4 74
6.2.7 Example 5-5-1 79
6.2.8 Example 5-5-4 83
Tables
Table 1. Glossary of terms and acronyms 5
Table 2. Categories of Meter Use Cases 20
Table 3. Meter Use Cases with "A" status. 21
Table 4. DCSML Message List 45
Table 5. Significance of bits in the first byte of the TL-Field 47
Table 6. Significance of bits in subsequent bytes of the TL-Field 48
Figures
Figure 1. Areas of communication in the AMI system 10
Figure 2. Areas of communication in the AMI system – layers of the protocol 11
Figure 3: Diagram of the sequence – single communication session PULL 14
Figure 4: Diagram of the sequence – two communication sessions PULL + PULL 14
Figure 5: Diagram of the sequence – two communication sessions PULL + PUSH 15
Figure 6: Diagram of the sequence – single communication session PUSH 15
Figure 7. LPU in Installation Category 23
Figure 8. Sequence diagram for LPU01 – correct situation 24
Figure 9. Sequence diagram for LPU02 25
Figure 10. Sequence diagram for LPU03 25
Figure 11. Sequence diagram for LPU04 – servicing mode 27
Figure 12. Sequence diagram for LPU04 – without servicing mode 27
Figure 13. Sequence diagram for LPU05 28
Figure 14. Sequence diagram for LPU06 29
Figure 15. LPU in Configuration Category 30
Figure 16. Sequence diagram for LPU07 31
Figure 17. Sequence diagram for LPU08 32
Figure 18. Sequence diagram for LPU09 33
Figure 19. Sequence diagram for LPU20 33
Figure 20. LPU in Readouts Category 34
Figure 21. Sequence diagram for LPU10 – "push" mode 35
Figure 22. Sequence diagram for LPU10 – "pull" mode 35
Figure 23. Sequence diagram for LPU011 36
Figure 24. Sequence diagram for LPU13 – "push" mode 37
Figure 25. Sequence diagram for LPU13 – "pull" mode 38
Figure 26. LPU in Control Category 39
Figure 27. Sequence diagram for LPU012 – readout in the "push" mode 39
Figure 28. Sequence diagram for LPU012 – readout in the "pull" mode 40
Figure 29. Sequence diagram for LPU012 – change of data in the "push" mode 40
Figure 30. Sequence diagram for LPU012 – readout in the "pull" mode 41
Figure 31: Sequence diagram for LPU016 42
Figure 32. Sequence diagram for LPU17 43
Figure 33. LPU in Reporting Category 43
Figure 34. Sequence diagram for LPU18 44
Figure 35. Sequence diagram for LPU19 44
Figure 36: Definition of grammar in ASN.1 notation 63
Figure 37: Response 1-1-4 in the APDU form 63
Figure 38: Query 1-1-1 in ASN.1 notation 64
Figure 39: Response 1-1-1 in the APDU form 64
Figure 40: Response 1-1-1 in ASN.1 notation 65
Figure 41: Response 1-1-4 in the APDU form 65
Figure 42: Query 1-1-4 in ASN.1 notation 65
Figure 43: Response 1-1-4 in the APDU form 66
Figure 44: Response 1-1-4 in ASN.1 notation 67
Figure 45: Response 1-5-4 in the APDU form 67
Figure 46: Query 1-5-1 in ASN.1 notation 67
Figure 47: Response 1-5-1 in the APDU form 68
Figure 48: Response 1-5-1 in ASN.1 notation 68
Figure 49: Response 1-5-4 in the APDU form 69
Figure 50: Query 1-5-4 in ASN.1 notation 69
Figure 51: Response 1-5-4 in the APDU form 70
Figure 52: Response 1-5-4 in ASN.1 notation 71
Figure 53: Response 5-1-4 in the APDU form 72
Figure 54: Query 5-1-1 in ASN.1 notation 72
Figure 55: Response 5-1-1 in the APDU form 73
Figure 56: Response 5-1-1 in ASN.1 notation 74
Figure 57: Response 5-1-4 in the APDU form 74
Figure 58: Query 5-1-4 in ASN.1 notation 75
Figure 59: Response 5-1-4 in the APDU form 75
Figure 60: Response 5-1-4 in ASN.1 notation 79
Figure 61: Response 5-5-4 in the APDU form 79
Figure 62: Query 5-5-1 in ASN.1 notation 80
Figure 63: Response 5-5-1 in the APDU form 81
Figure 64: Response 5-5-1 in ASN.1 notation 83
Figure 65: Response 5-5-4 in the APDU form 83
Figure 66: Query 5-5-4 in ASN.1 notation 84
Figure 67: Response 5-5-4 in the APDU form 84
Figure 68: Response 5-5-4 in ASN.1 notation 90
1 Glossary of terms and acronyms
Table 1. Glossary of terms and acronyms
Term / Explanation /AES / Advanced Encryption Standard – symmetric block cipher adopted by the National Institute of Standard and Technology.
AES-GCM 128 / Advanced Encryption Standard – Galois/Counter Mode – GCM is a double-functionality cipher and authentication mode. AES performs 10 (128-bit key) substitution-permutation cipher rounds. They consist of preliminary substitution, permutation matrix (mixing of rows, mixing of columns) and modification with 128-bit key.
AMI / Advanced Metering Infrastructure.
Comprehensive system of meters, communication systems and applications for gathering, storing and analyzing the metering data and managing the metering infrastructure.
APDU / Application layer Protocol Data Unit
Application / Centralized AMI application – responsible for gathering and managing the metering data
ASN.1 / Abstract Syntax Notation One – standard used to describe the structures designated for representation, coding, transmission and decoding of data
BER / Basic Encoding Rules – method of coding the data described by the ASN.1 specification
CA / Certification Authority – institution of trust, office of certification
CBP / Central Metering Database
CAZ / Central Managing Application.
Certificate / Public key and information on the entity's identity signed digitally by the office of certification
COSEM / Companion Specification for Energy Metering – set of specifications compiled by DLMS UA defining the IT model of the facilities, including, among other things, electricity meters
DCSML / Data Concentrator Smart Message Language – communication protocol constituting an extension of standard SML specification to include additional functionalities (e.g. multicast, broadcast). Created for the purpose of implementation of the AMI System in DSO
DLMS / Device Language Message Specification – communication-oriented application layer protocol designed to support, among other things, two-way data exchange with the electricity meters
DSO / Distribution System Operator
GSM / Global System for Mobile Communications (originally, Groupe Spécial Mobile) – mobile telephony standard
GPRS / General Packet Radio Service – method of sending data in packets in GSM networks
GZIP / Program used for file compression, based on the Deflate algorithm, constituting a combination of LZ77 algorithms and Huffman coding algorithm
HAN / Home Area Network – Home Network encompassing the devices within the Intelligent Building infrastructure, equipped with remote control and data providing functionalities (heating, air conditioning, household appliances and radio/TV equipment). In addition, HAN may be comprised of PCs and house terminals used for monitoring electricity consumption and managing the devices and meters.
Metering Infrastructure / Technical infrastructure, including hardware and software, whose purpose is to provide adequate communication between recipients of electricity andDSO, including information on electricity consumption. The Metering Infrastructure connects to the Application System via the Intermediating Infrastructure. The Metering Infrastructure will be comprised of power meters and concentrators as well as other devices connected to them, including HAN devices and meters of other utilities.
KDL / Metering Data Concentrator
KDLP / Metering Data Concentrator – Program.
LE / Electricity Meter.
LPU / Meter Use Case.
nN / Low voltage.
OBIS / Object Identification System – system of coding the COSEM model objects.
OSI / Open System Interconnection. – standard defined by the ISO and ITU-T organizations, describing the network communication structure.
PKI / Public Key Infrastructure – structure of trust, based on confirmation of authenticity with use of certificates issued by the hierarchy of certification offices.
PLC / Power Line Communication/Carrier – communication technique allowing to remotely send the data via the electricity cables.
PRIME / PoweRline Intelligent Metering Evolution – open specification defining communication in the lowest layers of the communication system after PLC, from the terminal devices (meters) to the data concentrator located in the medium-voltage/low-voltage transformer station.
SAK / Acquisition System.
SML / Smart Message Language – application layer protocol developed by the MeKo project group, designated to support, among other things, two-way data exchange with the electricity meters.
The MeKo project group is comprised of the following: Dr. Neuhaus Telekommunikation GmbH, E.ON Mitte AG, E.ON Netz GmbH, Emsycon GmbH, EnBW Vertriebs und Servicegesellschaft mbH, Landis+Gyr GmbH, RWE Rhein-Ruhr Netzservice GmbH.
MV / Medium voltage.
SSH / Secure Shell – standard of communication protocols used in the TCP/IP computer networks, in the client – server architecture. It is used for connecting to the remote computer, and provides encryption and allows authentication of the user by many methods.
S-FSK / Spread Frequency Shift Keying – one of the techniques for transmitting the data through the PLC network.
TCP/IP / Transmission Control Protocol/Internet Protocol – set of transmission (TCP) and network (IP) layer protocols providing a unified method of sending the data in various types of networks.
TLS/SSL / TLS (Transport Layer Security) – extension of the SSL (Secure Socket Layer) protocol, adopted as Internet standard, which aims at providing confidentiality and integrity of data transmission and ensuring authentication; it is based on asymmetric ciphers and certificates of X.509 standard.
WS-RT / Web Services Resource Transfer – protocol based on the popular WebServices technology used in case of data exchange between the applications operating in the TCP/IP network, created under the DSMR standard.
xDLMS / Extended DLMS – extension of the DLMS protocol to the DLMS/COSEM standard defined by norm IEC 62056-53.
XML / Extensible Markup Language – it is a markup language used for describing the data. It is the method of presenting the hierarchical structure of nodes and their attributes in the form of a "flat" text file with a precisely defined structure.
2 Introduction
This document is an excerpt from the document entitled "Communication Standard Between the Application and the Metering Infrastructure" (version 2.00).
The document contains the concept and the basic assumptions for the communication standard with a proposed custom DCSML communication protocol created especially for EnergaOperator SA's needs. The standard takes into account the needs and characteristics of the AMI System.
This document presents:
· use cases for communication between the Application and the Metering Infrastructure,
· description of messages,
· grammar of the protocol,
· examples of queries and responses in DCSML (in the APDU and source form).
Development of the communication standard takes into account the guidelines included in the following document:
[1] Stance of the President of ERA in the matter of requirements for intelligent metering and billing systems implemented by OSD E, taking into account the purpose and the proposed support mechanisms for the postulated market model. ERA 2010. http://www.ure.gov.pl/download.php?s=1&id=4295P1.3 AMI Application. Concept of the Integrated Application System. Central Managing Application. 2011.05
3 Concept for the communication standard in DSO
In this chapter we have presented the assumptions which were adopted for work on the proposed communication standard, and presented the concept of the standard based on the assumptions adopted.
3.1 Assumptions for the communication standard
3.1.1 General assumptions
The following general assumptions were adopted:
- It must ensure sufficient functionality to meet all the requirements of the AMI System in DSO.
- It must be open to all metering devices, not just power meters (natural gas, water, heat meters).
- It must ensure communication between devices of various manufacturers (which use that standard).
- It should be precisely defined so as to ensure conducting of tests guaranteeing cooperation between the devices.
- It must ensure communication between:
- KDL and SAK – if readings take place through KDL (PLC).
- LE and SAK – if readings are performed directly by SAK (GPRS, GSM, LAN/WAN).
In addition, in order to prevent the path to the author's solution from being closed, it is proposed that the following recommendations are met, however they are not mandatory.
- The protocol should be regulated by the standards, in order to guarantee its openness and development.
- Usage of the protocol should be verified through prior large-scale implementations.
3.1.2 Technical assumptions
The following technical assumptions were adopted:
- Due to limited throughput of connections between KDL and SAK, it is necessary to:
- minimize the size of the message (queries and responses),
- minimize network traffic between SAK and KDL (type broadcast and multicast messages).
- KDL is "non-transparent" which means that SAK communicates with KDL in the manner minimizing the network traffic (see the assumption above), and KDL is responsible for optimal organization of communication with LE.
- The manner of SAK's communication with LE should be unified regardless of the communication channel used. Accordingly, if the meter does not communicate with the infrastructure through PLC (but through e.g. GPRS) and therefore there will be no KDL between LE and SAK, Program Concentrator will be functionally inserted in KDL's place which will fulfill KDL's functions.
- SAK has to be able to send to LE the message in the "transparent KDL" mode.
- It is necessary to properly secure the data through the following:
- authentication,
- authorization and access rights,
- ciphering,
- data integrity (control and error correction mechanisms).
- We propose to use open solutions as far as implementation of data security measures is concerned.
- We propose to use prioritization at the level of lower communication layers as well as the application layer.
3.2 Overall concept of the communication standard
Communication standard should be reviewed in the following areas.