ISO 15118 Workshop 1.10.2015 - Schaufenster Elektromobilität
Transcription
ISO 15118 Workshop 1.10.2015 - Schaufenster Elektromobilität
Workshop zur ISO 15118 Im Rahmen des Schaufensterprogramms Elektromobilität Dr.-Ing. Marc Mültin Frankfurt am Main | 1.10.2015 E-Mobilität einfach gestalten Mit der Systemlösung von Chargepartner 1 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin ERFREULICH SURPRISINGLY EINFACH SIMPLE www.chargepartner.com Workshops and trainings on request The information given in this slideset is only a subset of the original workshop presentation. Interested in further in-depth workshops and trainings about ISO 15118? Contact marc.mueltin@chargepartner.com 2 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Agenda General technical introduction § § § § Protocols applied on ISO/OSI layers Message sets and sequences on application layer Renegotiation of a charging profile Guidance through the ISO 15118-2 document Security aspects § Security in ISO 15118: Confidentiality, integrity, authenticity (CIA) § Certificate handling Information to get started and contribute § International application, testivals, User Group § Available software to get you started § Online resources for further information 3 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com But First ... A Few Words About Chargepartner 4 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Our product: A multi-client capable Software-as-a-Service Platform for: § Charge Point Operators § eMobility Service Providers (holding user contracts) § Employers, Corporate Car Fleets, Parking Lot and Garage Operators Core functions: § Real-time monitoring of charging infrastructure § Authentication, authorization and billing of charge events § Easy to use hardware- and user-management § Load-management to avoid local grid overloads Who we are: § Continuous development since first project „Future Fleet“ in 2008 (with SAP) § 8 dedicated and enthusiastic professionals working in Walldorf near Heidelberg 5 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Our USPs and happy customers Independence Multi-client Capability Open System Architecture High Scalability Customizable And many more… (WinJet, B eijing) 6 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Protocols Applied on ISO/OSI Layers 7 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com ISO/OSI Layers and related protocols Messages and data formats (Finite state machines) Data representation as binary XML files (Codec) V2G Transfer Protocol (Session-Handling) Standard transport protocols (Client/Server) 8 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Session layer: Session handling via V2GTP § Vehicle-to-Grid Transfer Protocol (V2GTP) = standard transfer protocol between EVCC and SECC § Based on TCP/TLS: source and destination IP Address and port to establish and identify a connection for bidirectional exchange of byte streams Header (8 Bytes) Payload (Application layer messages) (0 - 4294967295 Bytes) Byte no. 1 2 Header field Protocol Version Inverse Protocol Version 3 4 Payload Type (how to decode payload) 5 6 7 8 Payload Length § EXI-encoded V2G message § SDP request / response message § Reserved / manufacturer specific use 9 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Session layer: V2G communication session handling SessionSetupReq(SessionID=0)/ Res(SessionID=23) SessionSetupReq(SessionID=23)/ Res(SessionID=23) SessionStopReq(ChargingSession=Pause)/ Res V2G Communication Session 1 (SessionID = 23) Pausing SessionStopReq (ChargingSession=Terminate)/Res V2G Communication Session 2 (SessionID = 23) TCP/TLS connection TCP/TLS connection Data Link Data Link Charging Session time Plug-in 10 09.10.15 Plug-out Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Presentation layer: Advantage of EXI over plain XML § Efficient XML Interchange (EXI) = binary representation of XML-based messages • • EXI-Grammar more efficient than parsing schema information of XSD file Speeds up message processing on embedded controllers § Coding efficiency of EXI format (based on EXIficient library) compared to XML Message Pattern XML schema EXI schema EXI strict EXI strict informed informed byte pkd bit pkd Compr. Factor Compr. Rate Message Pattern XML schema EXI schema EXI strict EXI strict informed informed byte pkd bit pkd Compr. Factor Compr. Rate SessionSetupReq ServiceDiscoveryReq S&PSelectionReq PaymentDetailsReq PowerDiscoveryReq LineLockReq PowerDeliveryReq MeteringStatusReq MeteringReceiptReq 637 781 813 556 1127 643 1172 490 1025 69 278 64 46 61 34 50 32 114 72 281 68 52 69 37 58 34 123 67 276 60 44 53 31 43 30 108 9,5 2,8 13,6 12,6 21,3 20,7 27,3 16,3 9,5 10,52% 35,34% 7,38% 7,91% 4,70% 4,82% 3,67% 6,12% 10,54% SessionSetupRes ServiceDiscoveryRes S&PSelectionRes PaymentDetailsRes PowerDiscoveryRes LineLockRes PowerDeliveryRes MeteringStatusRes MeteringReceiptRes 792 1013 563 545 2773 778 543 1338 547 42 83 33 33 138 37 33 94 33 52 89 35 35 166 41 35 114 35 37 77 31 31 115 32 31 84 31 21,4 13,2 18,2 17,6 24,1 24,3 17,5 15,9 17,6 4,67% 7,60% 5,51% 5,69% 4,15% 4,11% 5,71% 6,28% 5,67% Arithmetic Mean Max Min 805 1172 490 83 278 32 88 281 34 79 276 30 10,2 27,3 2,8 10,11% 35,34% 3,67% Arithmetic Mean Max Min 988 2773 543 58 138 33 67 166 35 52 115 31 19,0 24,3 13,2 5,49% 7,60% 4,11% a)o f message sequences and encoding efficiency for electric vehicle to grid interconnections. b) J. Schmutzler, C. Wietfeld: A nalysis In: V ehicular Networking Conference (VNC), 2 010 IEEE, 2 010, S . 1 18–125 Fig. 7. 1200 Quantitative Overview of V2G Request (a) and Response (b) Message Sizes in XML and various EXI modes Request messages: 10% (average compression rate) Response messages: 5,5 %pkd(average compression rate) XML schema informed XML schema informed EXI strict byte pkd EXI strict bit 2500 1000 800 09.10.15 600 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin 2000 byte byte 11 EXI strict byte pkd EXI strict bit pkd 3000 1500 SURPRISINGLY SIMPLE www.chargepartner.com Application layer: SECC discovery via SDP § EVCC uses SECC Discovery Protocol (SDP) to get IP address and port of SECC § Multicast messages on local link (to any SDP server (SECC) on local network) § UDP (User Datagram Protocol)-based protocol – simple connectionless transmission of data (no handshaking mechanism like in TCP/TLS, thus no guarantee of delivery, ordering, duplicate protection) 1 2 Security Transport Protocol 1 - 16 SECC IP Address Request 17 18 SECC Port 19 20 Security Transport Protocol Response If TCP or TLS connection is wanted If desired security level is offered/accepted 12 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Message Sets And Sequences On Application Layer 13 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Client/Server-based communication protocol § EVCC (Client) always sends request messages, SECC (server) responds within given timeout (between 2s and 5s, depending on message type) § SECC can trigger certain request messages by setting a flag in response message (e.g. for renegotiation of charge schedule) Every 60s at the latest Requests ESHL PLC Responses 2 – 5s after incoming request 14 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com The fantastic four (message sets) § Four message sets to be applied depending on identification mode and charging mode External Identification Means (EIM) Plug and Charge (PnC) (e.g. RFID, NFC, cash payment) (authentication & authorisation via charge cord) AC Charging EIM DC Charging EIM Optional Optional Value Added Services (VAS) Value Added Services (VAS) Identification mode 15 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin AC Charging PnC DC Charging PnC Optional Optional Value Added Services (VAS) Value Added Services (VAS) Optional Optional Optional Optional Certificate Update Certificate Install Certificate Update Certificate Install Message set SURPRISINGLY SIMPLE www.chargepartner.com Parameter-based selection of message set ISO 1 5118-2 d ocument: Figure 97 – Selection of Message S ets 16 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com ISO/OSI Layers and related protocols 17 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin ( ( SURPRISINGLY SIMPLE www.chargepartner.com V2G message definition on application layer § Remember the V2GTP (V2G Transfer Protocol) structure? Header (8 Bytes) Payload (Application layer messages) (0 - 4294967295 Bytes) § Each application layer message (after SDP is finished) is a V2GMessage V2GMessage Header Body § SessionID: unique identifier of V2G comm. session § Notification: used by SECC in case of error situation § Signature: used if certain V2G messages requires to be signed § Body: A request or response message of a chosen message set 18 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com In-depth slides about application layer messages in ISO 15118 available via workshop/training on request 19 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Guidance Through The ISO 15118-2 Document 20 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Requirement structure § ISO 15118-2: 350 pages § Around 850 requirements in total § Some topics (such as security aspects) not encapsulated in single chapter but spread across several chapters [V2GY-XXX] the requirement text Represents the ISO 15118 set of standards Individual requirement number Document part of the ISO 15118 document set (1 – 8) 21 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com ChargeParameterDiscovery request: Schema diagram § When implementing a certain message, have a look at § 1) schema diagram, 2) table for semantics, 3) related requirements § 4) XSD file (in case of ambiguity) 1 Schema diagram Optional parameter Message set dependant subtypes ISO 1 5118-2 d ocument: Figure 35 – Schema Diagram - ChargeParameterDiscoveryReq 22 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com ChargeParameterDiscovery request: Semantics table § When implementing a certain message, have a look at § 1) schema diagram, 2) table for semantics, 3) related requirements § 4) XSD file (in case of ambiguity) 2 Semantics table Optional Simple type / complex type ISO 1 5118-2 d ocument: Table 3 8 – Semantics and type d efinition for ChargeParameterDiscoveryReq 23 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com ChargeParameterDiscovery request: Requirements § When implementing a certain message, have a look at § 1) schema diagram, 2) table for semantics, 3) related requirements § 4) XSD file (in case of ambiguity) 3 Related requirements ISO 1 5118-2 d ocument: E xcerpt from requirements related to ChargeParameterDiscoveryReq message 24 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com ChargeParameterDiscovery request: XSD definition § When implementing a certain message, have a look at § 1) schema diagram, 2) table for semantics, 3) related requirements § 4) XSD file (in case of ambiguity) 4 XSD file ISO 1 5118-2 d ocument: E xcerpt from Annex C.6 V 2G_CI_MsgDataTypes.xsd 25 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com ChargeParameterDiscovery request: XSD definition § When implementing a certain message, have a look at § 1) schema diagram, 2) table for semantics, 3) related requirements § 4) XSD file (in case of ambiguity) 4 XSD file ISO 1 5118-2 d ocument: E xcerpt from Annex C.6 V 2G_CI_MsgDataTypes.xsd 26 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Further guidance to the ISO 15118-2 document § Response Codes: see Table 112 on page 194 § State machine for AC and DC messages with respective requirements: see Figure 101 on page 200 (ff.) § Schema definitions: see Annex C on page 260 (ff.) § SAScheduleListType: see 8.5.2.12 on page 119 (ff.) § Message examples: see Annex D on page 284 (ff.) e.g. „Time of Use-based SalesTariffs including relativePricePercentage“ on page 295 (ff.) Please read the standard thoroughly and ask the ISO 15118 user group if questions arise! § Application and implementation of certificates: see Annex E, page 305 (ff.) and Annex F, page 319 (ff.) § EVSE-ID and contract ID semantics: see Annex H, page 329 § Signature implementation: see Annex J, page 336 (ff.) 27 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Security in ISO 15118: Confidentiality, Integrity and Authenticity 28 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com The 3 main aspects of security § Confidentiality A message‘s content may only be read by the intended recipients, but not by unauthorised third parties Encryption and decryption by means of asymmetric/symmetric cryptography § Integrity An unauthorized modification of the sent message must be avoided or at least be detected Creation and verification of digital, XML-based signatures § Authenticity It must be verifiable if the communicating parties really are the ones which they claim to be Creation and verification of digital, XML-based signatures 29 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Usage of a hybrid cryptographical system Hybrid crypto system Asymmetric crypto system § Different keys (public / secret) for en- and decryption § Secure exchange of shared secret over unsecure channel possible § Expensive (CPU power) Used for calculation and exchange of a shared secret 30 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin Symmetric crypto system § Identical key for en- and decryption § Secure exchange of this key needs to be taken care of § Less CPU power needed (compared to asymmetric systems) Used for en-/decryption of session messages with shared secret (session key) SURPRISINGLY SIMPLE www.chargepartner.com The essentials of security shortly explained § Usage of key pairs in asymmetric cryptography (1 key pair / communicating party) Random number Generation of keys For decryption & creation of signatures (enabling authentication) 31 09.10.15 Secret key Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin Public key For encryption & verification of signatures (and thus authentication) SURPRISINGLY SIMPLE www.chargepartner.com The essentials of security shortly explained § Encyption with public key and decryption with private key using asymmetric cryptography Advantage: communicating parties don‘t have the hassle to secretly exchange the same key for en-/decryption before communication starts Public key Plain text Encrypted text Secret key 32 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com The essentials of security shortly explained § Signing with private key and verifying with public key using asymmetric cryptography Public key Signature Plain text Secret key 33 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Security parameters used in ISO 15118-2 § ECDH (Elliptic Curve Diffie-Hellman) key exchange § Key length of asymmetric keys: 256 Bit § Symmetric crypto system AES-CBC-128 § SHA 256 hash algorithm § Elliptic Curve Digital Signature Algorithm (ECDSA) § X.509 v3 certificates § PKCS#12 container for certificate chains and keys 34 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com In-depth slides about cryptography in ISO 15118 available via workshop/training on request 35 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com DKE Arbeitskreis fokussiert Zertifikatshandling § DKE/AK STD_1911.11.5 / AK 353.0.8 „Informationssicherheit für Elektromobilität“ § Ziel: Erstellung einer Anwendungsregel für die Applikation geeigneter Zertifikate (und entsprechender PKI) durch sämtliche beteiligte Marktakteure im Rahmen der ISO 15118 § Ansprechpartner: Andreas Harner (DKE) 36 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com TLS protocol allows for application of security concept § The Transport Layer Security (TLS) protocol allows for several standardized „cipher suites“ § Allowed cipher suite in ISO 15118-2: TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256 TLS protocol Symmetric crypto system AES Asymmetric key exchange using ECDH Signature algorithm ECDSA 37 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin AES with 128 Bit key length in CBC mode Hash algorithm SHA 256 SURPRISINGLY SIMPLE www.chargepartner.com Certificate Handling 38 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Certificate types and PKI hierarchy concept E.1.5 Overview of the resulting certificate structure ISO 1 5118-2 d ocument: Figure E.1 – Overview certificate structure Figure E.1 — Overview certificate structure 39 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin 09.10.15 Figure E.1 provides a visual overview of the resulting certificate structure and relevant validitySURPRISINGLY periods. SIMPLE www.chargepartner.com In-depth slides about certificate handling in ISO 15118 available via workshop/training on request 40 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Value Added Services 41 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Value Added Services (VAS) § Certificate installation/update is a VAS, many more are possible § Reservation of charge points § Downloading updated POI/navigation data § Multimedia (audio/video) § ..... 42 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com International Application, Testivals & User Group 43 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Internat. conformance and interoperability test events § Already four ISO 15118 test events (testivals) taken place § 3 of 4 on international level (Dortmund, Tokyo, Chicago) 44 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com ISO 15118 User Group § Purpose § Platform to exchange and discuss questions & answers regarding the implementation of ISO 15118 standard requirements § Get a common understanding and ensure interoperability § Access § Visit http://extmgmt.kn.e-technik.tu-dortmund.de/ § For an account, mail to: jens.schmutzler@tu-dortmund.de 45 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Available Software To Get You Started 46 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com OpenV2G project – Open source implementation in C § Licensed under the GNU LGPL v3 § First open source project on EV charge communication, initiated by Siemens CT in cooperation with TU Dortmund, CNI) § Addresses EXI-based V2G encoding/decoding (proof-of-concept) § Supports EXI codec for both ISO 15118 (AC/DC) and DIN 70121 (DC) § Project page: http://openv2g.sourceforge.net/ § Sourceforge code: http://sourceforge.net/projects/openv2g/files/ 47 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com eNterop Open Source - Reference implemenation in C § Funded by the BMWi during the eNterop research project § Reference implementation of EVCC side (only EIM) § Uses OpenV2G for message encoding/decoding § Sourceforge code: http://sourceforge.net/p/enterop/code/ci/master/tree/ReferenceImplementation/ 48 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com RISE V2G – Open source implementation in Java § Licensed under the Eclipse Public License v1.0 § First complete reference implemenation of ISO 15118-2 § AC and DC § EIM and PnC (including security aspects) § Intellectual property (IP) due diligence done by Eclipse Foundation § Safe for use in commercial software (if license requirements are followed) § Feel free to join me and contribute on GitHub: https://github.com/eclipse/risev2g 49 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com EXI codecs § EXIficient (written in Java) § Implementation of the W3C Efficient XML Interchange (EXI) format specification § Project page: http://exificient.sourceforge.net/ § Licensed under the GNU GPL v2.0 § Not applicable in commercial products (because of copy-left license type), but good to get started § OpenEXI (written in Java) § Implementation of the W3C Efficient XML Interchange (EXI) format specification § Project page: http://openexi.sourceforge.net/ § Licensed under the Apache License, Version 2.0 § Compatible with Eclipse License project RISE V2G uses OpenEXI 50 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Online Ressources For Further Information 51 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com Online ressources for further information § ISO 15118-1 standardisation document (Use Cases) (http://www.beuth.de/de/norm/iso-15118-1/187351349) § ISO 15118-2 standardisation document (Network and application protocol) (http://www.beuth.de/de/norm/iso-15118-2/205494624) § ISO 15118 User Group (http://extmgmt.kn.e-technik.tu-dortmund.de) § Dissertation (http://digbib.ubka.uni-karlsruhe.de/volltexte/1000042102) on: „Das Elektrofahrzeug als flexibler Verbraucher und Energiespeicher im Smart Home“ („The electric vehicle as a flexible load and energy storage device in a smart home“) § Der Insider-Blog zur Elektromobilität (www.smart-v2g.info/blog) § Normungsroadmap Elektromobilität (https://www.dke.de/de/std/e-mobility/Seiten/EMobility.aspx) 52 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com 53 09.10.15 Workshop zur ISO 15118 | Dr.-Ing. Marc Mültin SURPRISINGLY SIMPLE www.chargepartner.com