Good E-Roaming Practice - schaufenster...

Good E-Roaming PracticePractical Guide to Interconnecting the ChargingInfrastructure in the Electromobility Showcases

Good E-Roaming Practice 1

Executive Summary 3

Introduction 5

Status quo 5User Requirements and Use Case Descriptions 7Delimitation 9Describing the Solution within the Framework of the Showcase Interconnection 9

Technical Implementation of the Showcase Interconnection 12

Foundations of the Technical Architecture of the Showcase E-Roaming Solution 13Relevant Roles in E-Roaming 13Terms and Concepts Relevant for a Charging Infrastructure 13Models of Cooperation in E-Roaming 15Models for Technical Communication between E-Roaming Providers 16Authorisation at Charging Stations 19Contract-based Access Media 19Options for Ad-hoc Authorisation at Charging stations 20Information on the Position and Technical Equipment of Charging Stations 21Charging Points 21Charging Modes 22Charging Plug Types 22Charging Point Information for POI Searching 23Transaction Handling 24Test Scenarios 24HMI Definitions 25Systems Must Be Robust 31Data Exchange Processes Should be Ad-hoc 31Support Processes are Helpful and Customer-friendly 32Additional Use Cases 33

Blocking Charging Columns 33Opening Barriers and Reserving Parking Spaces 34Protocol Implications of Additional Use Cases 34

Recommendations Derived from the Initiative 37

Organisational and Contractual Aspects 37Visual Markings of Charging Points 37

Outlook 39

Appendix 40

Glossary 40Bibliography 42List of illustrations 43Legal information 44

Contents

Good E-Roaming Practice Executive Summary 3

Today, a single charge card or app allows users of e-ve-hicles to find and use publicly accessible charging points of different providers in all four showcase regions. An initiative within the promotional programme “Electro-mobility showcase” demonstrated in an interconnection project that this is possible both technically and from an organisational point of view. The solutions identified by this initiative were first presented at the eCarTec trade fair in autumn 2014.

This guide gives a brief description of the initial situ-ation, implementation, and results of this showcase project, which involved providers of e-mobility, charg-ing points, and e-roaming as well as users from all four showcase regions.

On this basis, the following recommendations for Good-E-Roaming-Practice are given:

▪ The parties involved in interconnecting the charging infrastructure should organise their cooperation in an extended Spoke model. This model combines differ-ent platforms (“hubs”) to which the regional market partners are connected by using defined frame agree-ments (“hubbing the hub”). The result is a substantial reduction in both the complexity and cost of trans-re-gional cooperation.

▪ A multi-platform approach, using integrated routing tables and a jointly defined inter-roaming protocol, can simplify the technical communication between e-roaming providers. The routing tables indicate the platform address(es) of all the parties involved. The joint protocol eliminates the need for adaptations be-tween platforms, and systems tied to specific e-roam-ing providers can continue to use the platform-specif-ic protocol if necessary.

▪ The inter-roaming protocol used between the various e-roaming providers can be extended on a modular basis. It should also be mandatory, freely available, as well as clearly defined with respect to communica-tion technology and data format, without incurring excessive cost.

▪ In order to successfully integrate different IT systems into e-roaming, all types of software tests should be conducted, including black box, white box, and grey box tests.

▪ E-roaming platforms must ensure a high level of secu-rity, high robustness, and quick reaction times to fulfil the needs of inter-regional interconnection. Custom-er-friendly support processes are also helpful.

▪ Online authorisation is desirable, even though it may lead to increased running times of authorisa-tion requests to the back-end. This makes e-roaming easier and facilitates ad-hoc access and payment via a smartphone app.

▪ Charging points, providers and end users must be bijectively identifiable to ensure easy reservation, authorisation, and billing at charging stations. The corresponding IDs have meanwhile been assigned throughout Germany. This is a milestone on the path to a national charging infrastructure.

▪ A bijective transaction ID that cannot be altered is necessary to trigger, process, and document charging processes in a consistent manner.

▪ End users should be able to quickly find and reliably reserve the charging points, all of which must be clearly marked so that their interoperability is easily recognizable.

▪ All charging points and their providers should provide dynamic POIs to enable users to plan their routes according to the status of charging points.

▪ In addition to providing interoperability, all charging stations should offer ad-hoc access for users without a contract.

▪ An industry standard for the human machine inter-face (HMI) is desirable in order to provide a uniform and understandable status indicator on the charging columns, as presented in this guide.

Executive Summary

4 Good E-Roaming Practice Executive Summary

Along with use cases directly related to the charging pro-cess, the participants of the showcase project looked into special features, such as immediate blocking of charging columns and the access to semi-public charging points with restricted access. The resulting implications for a highly sophisticated protocol require very close coordi-nation between all the parties involved.

The showcase initiative demonstrated how to tackle such a challenge by developing and strengthening a common understanding of the market and role of e-roaming among various players from different industries. In the next step, the project partners will define common minimum requirements for the roll-out of marketable applications which will then ideally form the basis of standards for an open and efficient access to the e-roam-ing market. These standards, which have already proven successful in other industries, could, in principle, also serve as a blueprint for European solutions.

Good E-Roaming Practice Introduction 5

In late 2013, an initiative was launched within the pro-motional programme "Electromobility showcase", with strong support by the respective project coordination agencies, designed to harmonise the ICT structures between the four showcases. It intends to implement e-roaming in such a way that customers can charge their e-vehicles based on a single car charging contract across different providers and regions.

This initiative presented its first result in a joint show-case at the eCarTec trade fair in Munich in autumn 2014, using prototypes to demonstrate the successful implementation of an e-roaming method featuring charging columns and access media from all the four showcases.

This document summarises the findings from this implementation in a guide called "Good E-Roaming Practice" and offers the basis for the interconnection of other regions and charging infrastructures. The initiative also invites interested companies to actively participate in the further implementation and exten-sion of e-roaming in Germany.

With their commitment, the partner companies of this initiative for the interconnection of platforms support the political and customer-friendly target set forth by the European Parliament and the Council of the European Union in its directive on the "Deployment of Alternative Fuels Infrastructure" which states: "The operators of recharging points shall be allowed to provide electric vehicle recharging services to custom-ers on a contractual basis, including in the name and on behalf of other service providers. All recharging points accessible to the public shall also provide for the possibility for electric vehicle users to recharge on an

ad hoc basis without entering into a contract with the electricity supplier or operator concerned."1

Status Quo

By October 2014, there were some 950 charging columns with about 2,000 charging points in the four showcase regions2. They are owned by different charg-ing station operators.

Thanks to its project ICTP (Standardised, Open Platform for e-Mobility Data3), the Lower Saxony showcase has a central ICT structure at its disposal, which provides access to the charging infrastructure available in the showcase. The partner companies directly involved in this project are T-Systems, Volkswagen, the German Aer-onautics and Space Research Centre (DLR), and komola.

In the Berlin-Brandenburg showcase, access to the public charging infrastructure of RWE and Ebee is implemented by Hubject GmbH. In addition, Bosch Software Innovations GmbH and the DAI laboratory at the Technical University of Berlin in cooperation with Hubject are carrying out a field trial related to e-mobil-ity designed to ensure access to the charging columns at Ernst Reuter Square.

Bavaria-Saxony has also presented heterogeneous solu-tions. While access in Dresden, East Saxony, and Leipzig is provided by the local utilities DREWAG / ENSO and Leipzig Municipal Utilities via the so-called "StromTick-et"4 (electricity ticket) and additionally in Leipzig by Hubject, the fast-charging columns installed along the A9 motorway are operated by E.ON, Siemens, and Hubject.

Introduction

1 Source: Directive 2014/94/of the European Parliament and of the Council of 22 October 2014 on the Deployment of Alternative Fuels Infra-structure, article 4, (8–9), URL: http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32014L0094&qid=1415713803036&from=EN.

2 Source: http://schaufenster-elektromobilitaet.org/.3 ibid.4 „StromTicket“ facilitates ad-hoc access to the charging infrastructure using codes sent via an app or SMS.

6 Good E-Roaming Practice Introduction

▪ Hubject GmbH offers its business partners a bilat-eral connection, supplemented with a standardised framework agreement, which provides all the partic-ipants with easy market access through the so-called "intercharge network".

▪ E-clearing.net pursues an open market model for bilateral and cross-functional contractual relations between the participating partners.

In the Baden-Württemberg showcase, the public charg-ing infrastructure of EnBW AG with over 600 charging points and the additional semi-public charging stations of Bosch Software Innovations GmbH are also operat-ed by Hubject GmbH.

Outside the showcase regions, three providers are currently offering platforms to access the charging infrastructure in Germany5:

figure 01: Standardising the Charging Interface - Overview (National Platform Electromobility [NPE], 2014, p. 28).

Europe USA Japan ChinaCombined Charging System: China GB / T

AC charging

type 2 type 1 type 1China GB / T

communi-cation

PWM/PLC* PWM/PLC* PWM/PLC* PWM**

charging power

max. 43 kW

AC 3ph

max. 19.2 kWAC 1ph

max. 19.2 kWAC 1ph

max. 12.8 kWAC 1ph

DC charging

Combo 2 Combo 1 CHAdeMO China GB / TCHAdeMO China

GB / T

communi-cation

PWM / PLC PWM / PLC CAN CAN***

charging power

max. 200 kW

in perspec-tive max.

350 kW

max. 90 kW

in perspec-tive max.

240 kW

max. 50 kW

max. 187 kW

standards IEC 62196-1 / -2 / -3ISO 15118

DIN SPEC 70121IEC 61851

IEC 62196-1 / -2 / -3, SAE J1772

ISO 15118, SAE J2931DIN SPEC 70121

IEC 61851

IEC 62196-1 / -2 / -3SAE J1772

IEC 61851-1 / -23 / -24

GB / T 20234, 1 / 2 / 3GB / T 27930

* PLC optional ** similar to IEC 61851 ***different depending on manufacturer, incompatible versions

5 See also NPE (National Platform Electromobility) 2014 Progress Report, 2014, p. 31f.).


With respect to hardware, however, the current charg-ing infrastructure is already highly compatible, as illustrated in figure 01 with its overview of connectible plug types.

However, substantial technical and organisational efforts by the various parties involved are still required to implement the vision of establishing e-roaming using compatible ICT interfaces, similar to the mobile telephone system. The first important step in this pro-cess is to ensure compatibility between the showcase regions.

User Requirements and Use Case Descriptions

The heterogeneity of the status quo described above makes it necessary to define the minimum require-ments a charging column has to fulfil in order to be included in the design of e-roaming use cases.

These minimum requirements are:

▪ The charging column has an ICT (internet) connec-tion.

▪ The charging column is compatible with OCPP 1.5 or offers similar features (Open Charge Alliance, 2012).

▪ The charging column has a local RFID card reader and/or a function for remote activation.

If these conditions are met, the following use cases should be made possible:

▪ Tesla Motors, Inc. prefers the approach of supply-ing their own customers with an adequate charging infrastructure.

In the following illustration of the status quo, each charging column is assigned to only one participat-ing platform. There are numerous access possibilities within these networks. However, they can be roughly divided into two categories:

▪ Local authorisation (card readers at the charging columns, mostly RFID)

▪ Remote activation (mostly by the user via app, SMS etc.)

It must be noted that, particularly with local authori-sation, the charging columns are not always integrated into an ICT infrastructure. But even if authorisation is effected through a request made to the central IT infrastructure, the column itself is not necessarily con-nected to it, as shown in the "StromTicket" (electricity ticket) example6. Integration into a modern energy infrastructure, however, requires a link to back-end systems and corresponding data connections.

The easiest access to a charging column would un-doubtedly be a cash-based system that releases a certain amount of electricity after the customer has inserted coins. In reality, however, neither cash nor credit or EC cards have become popular with charging infrastructure operators. One of the reasons for this is the fact that these solutions entail transaction costs for the operators which bear no relation to the low proceeds gained from individual charging processes. This is why operators still require their customers to provide specific access media, such as an RFID card or an app.

6 In this scheme, an authorisation command is sent to a centralised system via app or SMS and the user receives an mTAN (activation code) in response, which is to be entered at the charging column. (KEMA IEV – Ingenieurunternehmen für Energieversorgung GmbH, 2013).


▫ Activate platform B charging columns using an app.

▫ Receive a bill of the charging process, based on a Service Detail Record (SDR7), which is sent from platform B to platform A.

These criteria will subsequently be used as a reference when checking the implementation.

In the process, potential technical extensions of the charging infrastructure, for instance to OCPP 2.0, must be considered in order to meet future standards.

▪ Every customer of platform A should receive access to all charging columns of platform B.

▪ To this end, the customers of platform A should be able to:

▫ Find charging columns of platform B via an app or a website and determine their status based on dynamic Point-of-Interest (POI) data sent to plat-form A by platform B.

▫ Activate platform B charging columns using an RFID card ("MIFARE DESFire EV1" or "MIFARE Classic").

figure 02: Illustration of an authorisation process using an RFID card (Volkswagen mobility card, MoKa). In-house illustration.

RFID reading operation:

UID: 1234abc

Volkswagen MoKa

driverHubject platform

charging column charging infrastructure operator

e-mobility provider ICT platform

7 service detail record; a record used to transfer selected data related to the charging process for subsequent billing. This record is also called "charge detail record".


Describing the Solution within the Framework of the Showcase Interconnection

The aim of the e-roaming showcases was to implement a compatible charging solution for the four showcase regions and to demonstrate its interoperability.

The solutions were based on the four use cases men-tioned above:

Finding a Charging Column of Platform B and De-termining its Status for Users of Platform A

Exchanging POI data to find a charging point (EVSE = Electrical Vehicle Supply Equipment) is a prerequisite for using charging stations of different providers. The exchange of data between the platforms used in the showcase was based on a common data and interface definition to make sure identical information was ex-

Delimitation

The following methodical restrictions were made to reduce the complexity when implementing the first step of this initiative:

▪ Technical tests only included the activation of charging columns via e-roaming, not the billing of the related charging processes. Therefore, the next step will require a more detailed analysis of the con-tract models available for the various platforms.

▪ Other than RFID cards and apps, no access media was analysed, even if this media is already being tested in some of the showcase projects.

▪ Only charging columns featuring type 2 plugs with mode 2 and/or CCS 2 were tested.

figure 03: Illustration of an authorisation process using an RFID card (ChargeNow card). In-house illustration.

Charge Now

driver

Hubject platform

charging infrastructure operator

ICT platform

e-mobility provider

RFID reading operation:

UID: 1234abc

charging column


changed between all market partners. Figure 04 illus-trates the exchange of POI data between the platforms and the systems of their partners.

Activation of Platform B Charging Columns by Plat-form A Users by means of an RFID card ("MIFARE DESFire EV1" or "MIFARE Classic")

Activation with an RFID card via a card reader in-stalled at the charging station was selected for the showcase because this function did not require any changes to the existing charging infrastructure.

If a platform A user registers at a platform B charging column with his mobility card which is not known there, the charging station sends the card number to its IT system for identification. If the system is unable to identify the number, platform B forwards the request to the IT system of the roaming provider, which asks all the other platforms connected to it whether any of them can identify that card. In a positive scenario,

the mobility provider that knows the card number replies and signals assent to the activation of the charging column.

For the inter-regional showcase, this request was ex-tended to connect - for the first time - two independ-ent roaming providers, the ICTP platform granting access to the charging infrastructure in Lower Sax-ony and the Hubject platform granting access to the charging infrastructure of the three other showcase regions. The OICP protocol of the Hubject GmbH formed the basis of this approach.

The request triggered by an RFID mobility card issued by Volkswagen (pilot project) at a charging column in Baden-Württemberg was forwarded by the local provider EnBW to the roaming provider Hubject and from there on to the ICTP platform used in Lower Saxony (figure 02). From there the request was sent to Volkswagen, the responsible e-mobility provider, where the number was author-ised and the charging column in Baden-Württem-berg was activated.

figure 04: Illustration of a search for a POI. In-house illustration.

search EVSEEVSE search result

EVSE search

Hubject EVSEsearch result

status information

answer from repository

feedback to app

POI search back-end of e-mobility provider

Hubject platform

ICT platform

Hubject Search EVSEEMP ID, geo-coordinates,

plug type/charging facility

charging infrastructure operator


A similar information chain was used to activate an RFID mobility card issued by BMW at a charging column operated by enercity in Hannover (figure 03). The request was sent to Hubject via the ICTP platform and from there on to BMW, the responsible e-mobility provider.

In total, the showcase of the four regions implemented the technical integration of four providers of mobility cards and six providers of charging infrastructures, demonstrating that it was possible to tap the charg-ing infrastructure in Baden-Württemberg, Bavaria, Berlin, and Lower Saxony with a single card (e. g. the Volkswagen mobility card).

Activation of Platform B Charging Columns by Plat-form A users with an App

This use case was similar to the RFID card scenario in many aspects. The only difference was that the author-isation request was not triggered at the card reader of the charging column, but with a customer’s app, which initiated the activation via the e-mobility provider's back-end. Therefore, it is not specifically illustrated here.

figure 05: Remote authorisation at a charging infrastructure via the intercharge platform.

Hubject

case EMP = BMW

case EMP = Volkswagen

Hubject

EMP back-endBMW

EMP back-endVolkswagenICTP

CPO back-end connected to Hubject:

RWE stations in Berlin

12 Good E-Roaming Practice Technical Implementation of the Showcase Interconnection

Technical Implementation of the Showcase Interconnection

8 This role model can be found in a similar way in various sources. It is derived from illustrations of BDEW (Bundesverband der Energie- und Wasserwirtschaft e. V. = Federal Association of the Energy and Water Industry), the protocol specifications of OCHP (OCHP Open Clearing House Protocol), OICP (Hubject GmbH), and activities of the Green eMotion project (see for example: http://www.greenemo-tion-project.eu/upload/pdf/deliverables/D3_2-ICT-Reference-Architecture-V1_2-submitted.pdf, last access on 26 February 2015).

The task of interconnecting different charging infra-structures presents the parties involved with technical obstacles that can be overcome using various options. The following sections will first describe the basics

which are necessary to understand these options: the players and their roles, the technical objects and special terms as well as the possible organisational and techni-cal models for e-roaming cooperation.

figure 06: Relevant Roles in E-Roaming (source from Green eMotion)8.

CHARGING POINT OPERATOR A

[CPO]

E-ROAMING PROVIDER

E-MOBILITY PROVIDER 1[EMP]

E-MOBILITY-PROVIDER 2[EMP]

EV DRIVER WITH CHARGING CONTRACT

[EVC OID]

CHARGING POINT OPERATOR B

[CPO]

Good E-Roaming Practice Technical Implementation of the Showcase Interconnection 13

Terms and Concepts Relevant for a Charging Infrastructure

An extensive charging infrastructure is necessary to provide charging capacities for e-vehicles whenever demanded. There is still a wide variety of terms to describe them, such as charging station, charging column, or charging point. This is confusing for the users. For example, if they need assistance to start the charging process at a public charging station, one of the first questions the telephone support person asks them is what charging point they are at. In addition, setting up an integrated charging infrastructure across showcases requires an agreement on some of the basic term definitions and concepts related to the charging process. Standardisation in this area is still ongoing.

Below we have listed the concepts that played an im-portant role for our e-roaming initiative.

Charging station: Charging station is the term used for one or several charging columns. A charging station can be compared with a conventional petrol station featuring several fuel pumps.

Charging column: A charging column can be compared with a fuel pump at a conventional petrol station.

Charging point and sockets: A charging column has several charging points. A charging point (also called EVSE = Electric Vehicle Supply Equipment) is used to charge the battery of an e-vehicle with electric-ity. It corresponds to the hose of a fuel pump. A special feature in charging electric vehicles is the fact that a charging point may have several sockets because there are different types of plugs. For example, the charging column in figure 07 has two charging points (A and B), each of which supports two sockets (for Schuko plugs and type 2 plugs). However, only one charging process per charging point is possible at any given time.

Foundations of the Technical Architecture of the Showcase E-Roaming Solution

Relevant Roles in E-Roaming

The user drives an electric vehicle and wants to use the charging infrastructure in the public and semi-public space. Typically, he has a contract with an e-mobility provider facilitating this use.

Based on this contract, the e-mobility provider (EMP) gives the user the opportunity to use charging infra-structures via a service that includes the detection and activation of charging stations.

The charging point operator (CPO) operates the charging infrastructure or a part of it with legal responsibility and may issue invoices for its use. A charging point operator may draw on other providers for his business, such as network operators, electricity providers, and charging station manufacturers.

The e-roaming provider connects the services offered by the EMPs and CPOs that cooperate with him across regions. Along with the technical interconnection, he provides other services for his partners, supporting them, for instance, with billing procedures.

In practice, these roles overlap. Many charging point op-erators let their customers use charging infrastructures, which means that they are providers of e-mobility at the same time. The five large German electricity providers are a good example. They operate a charging infrastruc-ture to which they also provide access for their custom-ers. On the other hand, there are providers of e-mobility that operate their own charging points. Among others, this refers to car manufacturers that either install charg-ing boxes for their customers on private property or even operate public charging stations like Tesla.


Energie- und Wasserwirtschaft e. V., BDEW) according to ISO15118, which assigns a unique ID to each legal person.

The third section can be freely assigned by the charg-ing point operator, even though there are differences between the standardisation proposals by ISO and DIN. For example, the ISO standard demands that the third section should always start with "E" for better recognition as an EVSE ID related to electromobility. Other differences include the accepted symbols and the length of the third section. See the BDEW website for more information.

Since 01 March 2014, every charging point of an op-erator is assigned a worldwide unique EVSE ID. For this purpose, the existing DIN format mentioned above is replaced by a new ISO format with the following syntax:

‚DE*A23‘*E45B*78C

This syntax consists of the country-specific operator ID (here: DE*A23‘), followed by the charging point ID [https://bdew-emobility.de/]. The separator‚*‘ in the syntax is mandatory.

It is imperative that each charging process can be traced to a specific charging point. This is a prerequi-site for activating charging columns (e. g. via smart-phone) and in particular for measuring the power consumption for the purpose of billing.

Since a charging point is the only object that can actually be uniquely assigned to a charging process, its clear identification is essential. This is the purpose of the so-called EVSE ID. It consists of several sections, similar to the IP address of computers in the internet. The format of the following two examples is taken from older standardisation initiatives:

▪ DE*ABC*EABC123BDC456 (ISO 15118-2:2014 – Ap-pendix H (ISO, 2014)9)

▪ +49*123*123456789 (DIN SPEC 91286 (DIN, 2011))

The first two sections of the EVSE ID refer to the charging point operator, uniquely identifying him in a country. If an operator is active in several coun-tries, it is advisable to use different operator IDs. In Germany (country code "DE"), the administration of operator IDs was mandated to the Federal Association of the Energy and Water Industry (Bundesverband der

figure 07: Simple model of a charging column with two charging points and four sockets.

socket for charging cable (e. g. Schuko plug)

charging point A(EVSE)

charging point B(EVSE)

CHARGING COLUMN

socket for charging cable (e. g. type 2)

socket for charging cable

(e. g. CCS)

socket for charging cable

(e. g. type 2)

9 The ISO currently consists of eight parts, but only "part 1" and "part 2" are assigned the status "published". All other parts are still in process.


Along with every charging point, every user must be uniquely identified as well. Only this makes the assign-ment of a charging process to a user and the correct billing of the charging process possible. The user is identified through the contract ID, which is also called EMA ID (e-mobility account identifier) or EVCO ID (electric vehicle contract identifier). For this number as well, BDEW clearly assigns the first section (= provider ID) to an e-mobility provider in Germany, as stipulated by ISO 15118. For the customer ID, a "C" is prepended to the number instead of an "E" to emphasise that it is a contract number. As an alternative, identification ac-cording to DIN SPEC 91286 is also used on the market.

Models of Cooperation in E-Roaming

The public infrastructure should be made available not only to local charging point operators and providers of e-mobility, but also to regional and national providers of e-mobility services like car manufacturers, car-sharing companies, and fleet providers. This requires a compre-hensive approach to cooperation, which was also taken in the showcase initiative, granting principally every potential market participant access to e-roaming. Charg-ing station operators must open their charging points for other market players, thus maximising the number of users of their charging infrastructure.

Instead of interlinking a large number of bilateral user contracts and different interfaces for communication between proprietary systems in a meshed network, a joint framework agreement with a technical interface like in a hub and spoke model is recommended for this process. Additionally, an extended spoke model permits linkage and interaction between hubs on the basis of defined framework agreements, if in line with the corporate strategy. This enables municipal utilities and private businesses to efficiently participate in an e-roaming scheme.

figure 08: Illustration of cooperation models for e-roam-ing. In-house illustration.

Bridge Bridge

Bridge

Meshed Network

Hub and Spoke Model

Spoke Model „Interroaming“


The main target of the initiative "Interconnecting the four showcases" was to use the promotional pro-gramme "Electromobility showcase" to demonstrate that it is technically feasible to connect e-roaming providers with each other. Therefore, a method was chosen that permitted a fast and simple technical im-plementation without the need to make major changes to the systems that existed in the showcases. Figure 09 shows this implementation.

In this model, the e-roaming partners set up a direct link with each other, which is implemented via a single communication protocol, to which the participants have to agree. The showcase selected the Open Inter-charge Protocol (OICP) for this purpose.

With card-based authorisation at a charging station, however, no information on the target provider of e-mobility is available. This is due to the unstructured format of the RFID card number because RFIDs are assigned without structuring sections that indicate the country or e-mobility provider. Since neither the target e-roaming provider nor the associated e-mobili-ty provider can be determined from the ID, a broadcast similar to a radio broadcast has to be sent to every connected e-roaming provider. This broadcast, howev-

The benefits of a spoke model or a hub and spoke model in terms of reducing complexity, costs, and non-transparency have already become evident in the telecommunications and finance industries. Overall, these models allow for efficient, uninhibited, and sustainable market growth, provided that efficiency factors like system security, fees, and speed are taken into account.

For this reason, the spoke model was chosen as the ba-sis for cooperation between Hubject and T-Systems in the showcase. The technical communication between the platforms and their connected systems was based on the OICP protocol. The showcase partners suggest the same approach for any interconnection beyond the scope of the showcase.

Models for Technical Communication between E-Roaming Providers

E-Roaming providers can be connected with each other in various ways. The basic requirement in all these cas-es is that every e-mobility provider and every charging point operator can be connected via a coordinated IT interface.

figure 09: Multi-platform approach via bilateral connections. In-house illustration.

bilateral connections, several protocols and broadcasting

A

B


In the diagram on the left, the routing tables are stored with all e-roaming providers in the same manner and must be mirrored between them. This may seem complicated to organise, but is, in fact, quite easy to implement.

The diagram on the right, in contrast, shows the cen-tralised administration of the routing table by a single provider. While this scheme keeps the amount of effort for communication required by each provider almost on the same level, synchronisation of the routing infor-mation becomes easier. Coming to an agreement with respect to such a centralised administrative entity, however, is a political challenge in view of the numer-ous regional, national, and European initiatives.

In addition, both models still require the messages to be converted into the language of the respective e-roaming provider. This drawback can be overcome by aligning the communication protocol between all pro-viders, along with introducing routing tables. Figure 11 shows these models with decentralised and centralised routing table administration, respectively.

These models no longer require protocol adaptations, at least not between e-roaming providers. Rather, all

er, must be in the language of the respective provider. This simple model also has limitations when it comes to remote activation since this feature requires broad-casting as well, if more than two e-roaming providers are connected. Current technologies do not yet offer a clear and publically available assignment for charging point operators and e-roaming providers. To be sure, this simple type of technical communication is practi-cal within the narrow scope of the showcase initiative, but every additional e-roaming provider would make it more complex.

The requirements for higher complexity are met by another model, the communication flow of which is shown schematically in figure 10.

The single most important factor for the efficiency of this model is the information indicated by the text boxes next to the nodes. They symbolise so-called routing tables that state which player can be addressed via which roaming platform. E-roaming providers use this information to avoid broadcasts and to target the corresponding player via his pro-vider (unicast). This helps avoid data scattering and unnecessary system requests and is, therefore, a very desirable objective.

figure 10: Multi-platform approach via routing tables and protocol adaptations. In-house illustration.

routing of requests (protocol adaptation and mirrored routing tables)

routing of requests (protocol adaptation and

centralised routing repository)

A

B

A

B


many ways to facilitate, for instance, the reservation of specific charging points (e. g. at fast-charging columns along motorways) or grant access to parking spaces.

Another important requirement for an inter-roaming protocol - along with its modular expandability - is its high technical flexibility, so that it does not have to explicitly take special features of individual providers into account. Other important factors for the quality of such a protocol are its reliability and open availability. At the same time, the cost of its development (shared by several partners) and implementation in various systems play a major role for its viability and accept-ance. Another interesting factor is the communication technology selected for the exchange of data. In this context, approaches like REST or SOAP are available for implementation. Both systems are well established in internet communication. REST stands for Rep-resentational State Transfer and is a method for the lo-cation-based access to web resources with unchanging syntax and semantics. Today, REST is often mixed with other methods like SOAP, for instance when describing methods for the access to web resources. The SOAP protocol is a standard of the World Wide Web Consor-tium (W3C) used for exchanging predefined data via the internet.

providers involved define and use a so-called "in-ter-roaming protocol" that transmits essential infor-mation such as:

▪ Charging point and contract ID

▪ Status information on charging points

▪ Charging process data (amount of electricity, dura-tion)

Examples of potential basic protocols for this ex-change are the Open Intercharge Protocol (OICP) of Hubject GmbH and the Open Clearing House Protocol (OCHP). One of the most important forums where options for harmonising this exchange are discussed is the eMI3 group (http://emi3group.com/).

An inter-roaming protocol can have different levels of sophistication. On the first level, the exchange of charging point information can be harmonised, including real-time status, exchange of authorisation messages and of information after the charging process has been completed. This makes both card-based and remote authorisation (e. g. via smartphone) possible. The joint protocol can subsequently be extended in

figure 11: Multi-platform approach via routing tables and an inter-roaming protocol. In-house illustration.

routing of requests (inter-roaming protocol and

mirrored routing tables)

routing of requests (inter-roaming protocol and

centralised routing repository)

A

B

A

B


Which of the formats and architectures described will finally prevail depends on the following factors: the number of players in e-roaming and their preferred economic and technological approaches, the expected organisational challenges in the standardisation of communication protocols and the expected overall number of e-roaming charging events.

Authorisation at Charging Stations

Users have to authorise themselves at charging points of a charging infrastructure in order to charge their ve-hicles there. The type of authorisation differs between users who have a contract with one of the e-roaming partners and those who don't.

Contract-based Access Media

In a contract-based access to the charging infrastruc-ture, the user has contractual relations with an EMP who, in turn, has contractual relations with the CPO of the charging point to be activated. This ensures that the CPO can bill the charging process. Irrespective of the detailed terms of the contract, the showcases focused on two types of authorisation:

▪ Local authorisation via RFID card

▪ Remote authorisation via mobile phone (app or SMS)

For authorisation via RFID card, MiFare Classic 1K (NXP Semiconductors, 2014) and MiFare Desfire EV1 (NXP Semiconductors, 2010) were selected. Both cards are very common in existing charging infrastructures of the showcase regions. The 4-byte NUID (Non-Unique ID) (NXP Semiconductors, 2014, p. 18) was used for reference.10 (Examples: Mifare Classic UID 06558eb3 and Mifare DesFire EV1 UID

The definition of the inter-roaming protocol is also relevant for the data format, with a number of compet-ing formats. One of them is JavaScript Object Nota-tion (JSON). Originally created to provide persistence for JavaScript objects, it is currently widely used as a reduced data format in many web applications and particularly in the area of mobile applications (apps). In other cases, it is used without JavaScript imple-mentation. It often competes against XML-based data formats, even though it is designed for completely different use cases. XML in combination with an XML schema focuses on highly structured and readable doc-uments, whereas JSON is processed in a very reduced manner and initially without a schema when a mes-sage comes in. The benefits and drawbacks depend on the respective use case. A decision in favour of JSON is often based on criteria like a narrow bandwidth and simple processing. The need for a fixed structure and standardisation with processing security for deep integration into existing corporate applications is often the basis for choosing XML and a suitable XML schema. XML-based standards like XML Schema, RDF (Resource Description Framework) or OWL (Web On-tology Language) show their full benefit if machines are to evaluate semantics, i. e. if machine-machine communication tends to move towards processing intelligence.

Other data formats are possible, but present significant organisational or technical challenges. A good example is the use of software agents that are able to find the target provider and to convert messages. IT technol-ogies from the semantic web play a major role in this process. The use of these agents, however, requires the exact semantic description of services like the search for charging points or the authorisation at a charging point. In principle, the use of centralised architectures via Enterprise Service Bus systems is also an option. In this case, charging authorisations would be cen-trally stored in the bus as events, so that all connected providers could use the event description to determine if they could process it themselves.


system-independent charging option via media that provides direct access to a charging column and a channel for immediate payment (e. g. mobile or smartphone media, special charging cables, car park tickets, card terminals etc.).

▪ Public charging columns that have already been installed should be retrofitted for ad-hoc use or reconstructed in a timely and efficient way.

▪ Every charging column should provide other access options beyond ad-hoc access. Setting up trans-re-gional e-roaming platforms is especially preferable since this would grant users a contract for nation-wide access to the charging infrastructures of differ-ent providers.

These recommendations are in line with the experience of the showcase initiative which, among other things, was able to implement different methods of direct payment that supplemented existing contract-based access methods.

A good example in this area is the "StromTicket" (elec-tricity ticket) introduced by the local utilities DREWAG – Stadtwerke Dresden GmbH (DREWAG) / ENSO En-ergie Sachsen Ost AG (ENSO) and Stadtwerke Leipzig GmbH in 2013. The StromTicket was developed as a simple and cost-efficient access and billing system that uses apps, SMS, or the internet to communicate between mobile devices of users and charging points and is connected to the e-ticket systems HandyTicket and easy.GO that facilitate access to public transport12. The StromTicket is designed for European users, with billing based on transactions via safe payment methods like SEPA direct debit, credit card, giropay or through the mobile service provider.

045A4C0A962A80.) In this setup, the NUIDs are stored at various positions in the IT system of the con-tract partners. Therefore, an ID unknown to the CPO has to be clarified with the roaming partners.

The charging column is activated without direct phys-ical contact to the charging point. The showcase used a web-based solution via smartphone apps for this purpose. In this scenario, the user sends the EVSE ID of the charging point of be activated to the back-end of his EMP who forwards the request to the CPO or his roaming provider (for details see p. 16 ff.). This pro-cedure requires the EMP to supply his customer with such an app and to clearly identify him as the end user. However, in the Roaming Showcase, the setup and user interface of the apps were not given close attention, nor was the communication via ISO15118 since it is currently not very common on the market

Options for Ad-hoc Authorisation at Charging stations

Interoperable access systems are mandatory for a cus-tomer-friendly and efficient charging infrastructure. It is recommended, however, to offer additional access for ad-hoc users without a contract. This could make the charging infrastructure available to a wider public and also encourage its use by "casual customers".

The need for a possible ad-hoc use is also emphasised in NPE's current recommendations that can be sum-marised as follows:11

▪ Starting in mid 2015, a charging infrastructure with public access will be set up that also includes ad-hoc use. This term denotes a spontaneous and

10 For reading the ID, the NXP specification (NXP Semiconductors, 2010; 2014) stipulates the little-endian system. However, one result of the roaming showcase of the four regions is that field implementations include both little-endian and big-endian systems. In order to handle this issue in a pragmatic manner, both types (little- and big-endian) were stored in the databases of the EMPs.

11 See NPE Report 2014.


other than EVSE IDs within a charging infrastructure. For example, a charging infrastructure that is based on the OCPP protocol is assigned a charging station ID (like "Hanover town hall") and every charging point is assigned the so-called connector ID, a number starting with 1. In the OCPP protocol, the connector ID de-notes the entirety of all charging points in the charging infrastructure. If a charging point is equipped with an electric meter, the connector ID is identical to this meter, which measures power consumption and does the billing for the electric utility.

A pair consisting of charging station ID and connector ID denotes a charging point with its corresponding EVSE ID. It is desirable that the latter is firmly associ-ated with the physical charging point and that it can be changed if the charging point is replaced. The charging station ID also denotes the device, not the position. When a charging column or a mobile card is replaced, the charging station ID for that location may change.

In order for a charging point to be activated via a smartphone app (in addition to a connected card reader), the user must be able to read its ID, ideally the EVSE ID, so that he can enter it into the app of his smartphone. Alternatively, the ID could be a QR code that could be read off the smartphone. The showcase project did not consider any other reading types. If the user is unable to clearly identify the addressed charg-ing point of a charging column, but only its position, there is the danger that his smartphone might trigger the charging process at that position for another charg-ing point or user.

The card reader of a charging point should support different card formats as described in "Terms and Con-cepts Relevant for a Charging Infrastructure" (p. 13 ff.).

Another option for ad-hoc access is being tested in the showcase project "Technology, Feasibility, and Accept-ance of DC Charging along the Key Motorway Axis A9 (Munich – Nuremberg – Leipzig)". It provides access to the charging columns via a direct SMS payment sys-tem, so that any mobile phone that has been activated for German payment services can be used for charging and payment purposes. DC charging costs €3 per 10 minutes charging time, AC charging costs €2 per 30 minutes charging time. Since the summer of 2014, all fast-charging infrastructures along the A9 have been connected to the e-roaming platform intercharge of the provider Hubject.

Other ad-hoc payment schemes, for example from RWE, use common e-commerce methods like PayPal and credit card payment.

Information on the Position and Technical Equipment of Charging Stations

The basic structure of a charging infrastructure is de-scribed in "Terms and Concepts Relevant for a Charg-ing Infrastructure" (p. 13 ff.). Every charging point is assigned an electric meter that measures consumption. Every charging point can be accessed from outside via one or more connectors.

Charging Points

A charging infrastructure offers charging columns with several charging points. The operator can use IDs

12 http://stromticket.de/uber-uns/.


The charging point status can be changed either phys-ically on site or remotely by the centralised service of the CPO. The charging point returns the resulting sta-tus to the centralised service. This feedback should be given as fast as possible and be forwarded to the EMPs involved.

Charging Modes

The following charging modes are available:

Mode 1 (not recommended): Charging with alternating current (AC) at a customary socket or at a "CEE socket" with 480 volt and 16 ampere. No communication be-tween the energy release device (socket) and the vehicle.

Mode 2: Charging with alternating current (AC) at a customary household socket, but with an "In Cable – Control and Protection Device" (IC-CPD) inside the charging cable (IEC 62752). This cable connects an electric vehicle, which is normally charged in mode 3, with a customary socket or a CEE socket (IEC 60309). Communication between the IC-CPD and the vehicle.

Mode 3: AC charging is only possible using a dedicated type 2 socket or a mode 3 charging cable permanently connected to the installation. Communication between the energy release device (charging column) and the vehicle.

Mode 4: Fast charging with direct current (DC). Communication between the energy release device (power outlet) and the vehicle.

Charging Plug Types:

The plug type classification conforms to the interna-tional IEC 62196 standard.

The validity of the cards should be verified cryptograph-ically to prevent criminals from cloning them. In order to use the cards for e-roaming, an internet connection is necessary for the charging point.

A charging process (transaction) at a public charg-ing point requires prior authorisation, for instance by placing the RFID card on a reader. CPOs and EMPs often use offline authorisation to verify cards by transferring lists to all charging columns of the CPO. Offline authorisation has the advantage of short response times and functions reliably even in the case of connection errors, but in the case of roaming, the authorisation request must be sent to the back-end because normally the user is not known to the CPO. Generally, however, online authorisation offers more benefits. After all, it facilitates ad-hoc access and pay-ment via a smartphone app by the user, which makes it preferable for the market participants.

The electric meter of each charging point records the reading at the beginning and the end of a charging process and sends this data as a service detail record (SDR) to the CPO who forwards it to the EMP of the charging card. Depending on the charging column manufacturer, the SDR transmits either the actual, consecutive reading or merely the difference, with null as the starting value. If the preceding authorisation was carried out online at the charging point, it might be impossible to assign an authorisation request to the resulting SDR at the back-end.

The technical equipment of a charging point can vary widely due to the large number of different plugs types and charging modes. The technical properties of each plug type determine which charging modes can be used. A charging point can be accessed from outside via one or more connectors. Depending on the manu-facturer, a consumer can engage more than one plug at the same charging point.


Charging point handling varies depending on the manufacturer of the charging column. Some charg-ing columns require an initial user authentication to open the shutter for the plug, while at other charging columns the cable must first be plugged in before the charging card can be authenticated.13 An instruction easy to understand should be attached to each charg-ing column at a clearly visible position.

If a charging point has been reserved by a user and is therefore blocked for others, this user should be able to recognise the corresponding column early on when entering the charging station, for example by a prom-inent reservation number at the device, especially if it contains many charging columns. The reservation sign should be active for a maximum of 15 minutes and go off if the user activates another column. Fault conditions of the column should be indicated not only by blinking or acoustic signals, but also by means of internationally understandable pictograms or messag-es in several languages.

The charging infrastructure operator (CPO) maintains a centralised service with a list containing all charg-ing points and their technical parameters as well as location data.

Charging Point Information for POI Searching

Data on the technical equipment and the location of each charging point should be made available to the service providers involved for perimeter searching. EVSE IDs in ISO format should be used as identifiers of the charging points. In addition, the record should contain a location ID so that adjacent charging points can be displayed in clusters on road maps. Further parameters to be provided include: GPS position and address, public accessibility (onstreet/offstreet), permanent availability, support of remote start/stop,

Section IEC 62196-1 of this standard refers to the plug types listed in IEC 60309. The plugs for industrial use described in it have also been widely used as charging plugs for e-vehicles, whereas the charging plug-in systems described in IEC 62196 were designed and developed specifically for e-vehicles.

Section IEC 62196-2 describes the plug types for connections to alternating current (AC), whereas IEC 62196-3 deals with the plug types for connections to direct current (DC) in fast-charging infrastructures.

The following types of charging plugs were included in the list for both sections of the standard:

▪ IEC 62196-2 "type 12 – single phase vehicle coupler – adopts the specification from SAE J1772/2009

▪ IEC 62196-2 "type 2" – single and three phase vehi-cle coupler – adopts the specification from VDE-AR-E 2623-2-2, the so-called Mennekes plug, which is offered with an optional shutter to comply with legal provisions in some EU countries. This type is preferred in the EU.

▪ IEC 62196-2 "type 3" – single and three phase vehi-cle coupler with shutters (not relevant for Germany) – adopts the proposals of the EV Plug Alliance and is preferred in France. This type, however, bears a higher risk of failure in winter due to the mechanics of the shutter. The plug itself differs from type 2.

▪ IEC 62196-3 "CCS": direct current coupler and single and three phase vehicle coupler combined – CCS supports both AC charging (alternating current at 480 volt and up to 63 ampere) and DC charging (direct current at 600 volt and up to 200 ampere). This is an extended type 2 plug featuring two addi-tional DC PINs, which reuses, among other things, the analogous signal lines (resistance values).

13 Some vehicle permit charging only with the doors locked. When opening a door, the process is suspended.


E-RoamingAuthorizeStart). This transaction ID is part of the response and must be included in every subsequent request that is part of this process. If a request contains an invalid transaction ID, the requesting CPO receives a negative response and the process is cancelled.

Partners using back-end systems can use a transaction ID concept of their own. The roaming systems in-volved support this by optionally permitting a second request parameter, referred to as partner transac-tion ID. Then they use this partner ID to point to the system-related transaction ID and add it to each operative response. The respective back-end system of the CPO will be responsible for assigning the partner transaction ID.

In the future, the transaction ID will be the most important process ID for e-roaming services. The roaming providers involved use Globally Unique Identifiers (GUID) as transaction IDs, which ideally are only machine-readable and do not contain any human-readable information. A GUID is a seemingly random succession of letters and numbers which are, however, uniquely combined and do not occur in the same form more than once.

Test Scenarios

The interconnection of different IT systems in e-roam-ing as realised in the projects of the showcase initiative must be supplemented by specific tests in order to achieve an equivalent implementation of the role-spe-cific web services by CPOs and EMPs (online and offline) and of the operations in all partner back-end systems. Reliable communication between the roaming platforms and the back-end systems of the partners is particularly important in this respect. It is the prereq-

support of a reservation function for the plug types and charging modes offered.

Transaction Handling

In order to ensure consistency in triggering, process-ing, and documenting charging processes, a bijective, unalterable transaction ID has been introduced. After referencing a process, the use of such a transaction ID makes sure that wrong assignments are prevented and that each process can be bijectively associated across all processing entities, regardless of sender and recipient.

The purpose of such a transaction ID becomes clear with the following example:

The customer of an e-roaming provider wants to activate a charging point using his RFID card. First he authenticates himself with this card at the charging column. The CPO then sends the authorisation re-quest to the roaming provider. If the customer's EMP returns a positive response to this request and grants permission for the charging process, the CPO must be able to clearly process this permission. This proce-dure assures the EMP that the transaction is valid and allows him to correctly assign the associated billing information at the end of the charging process (charge detail record).

Technically, this method is implemented in a function-al session of connected web service operations using a single transaction ID.

In order to associate all relevant operations with the correct process, a transaction ID is assigned after the first authorisation request has been received (e. g.


that are as close to reality as possible. Real tests re-quire a wide variety of tests to check the conditions un-derlying the technical functions. They start with black box tests representing the technical process, illustrated by logical processes and a technical connection. In the next step, the analyses necessary for a white box test are added, without the need to alter the process of the technical tests.

HMI Definitions

Users of charging infrastructure are currently faced with numerous access and operating options. So far, no industry standard has been established for the human machine interface (HMI).

In terms of hardware, there are three basic categories of HMIs (see figure 12):

▪ Category 1 ("reduced HMI"): Charging columns with light elements or LEDs for visual feedback to the user

▪ Category 2 ("full HMI"): Charging columns with touch screen for interaction with the user

▪ Category 3 ("HMI without hardware"): Charging columns offering no option for direct interaction. Access via smartphone.

In the case of charging columns featuring an RFID reader in front of which the user must hold an RFID card for authorisation (see figure 12 left and centre), experience has shown that visual marking on the charging column is necessary. Otherwise, the user may not know where exactly he should hold his card at the charging column.

uisite for productive charging processes. In line with common IT test methods, the showcase initiative car-ried out mainly black box and white box tests. Howev-er, comprehensive grey box tests were also used.

Black Box Testing

This test method only checks the function of the soft-ware technologies, not their implementation or the state of the respective programmes. Thus, only the user interface is tested, in this project especially the use of different portals. Consequently, these test methods were also used for the interconnection project, though they were not actively triggered by user input, but automatically processed. A successful black box test proves that the interface and corresponding data allow proper usage, while leaving potential errors in system communication unattended.

White Box Testing

The white box test focuses on the internal function-ing of a software system. It includes its source code if necessary, which permits access to the entire system. Every single component of a system can be tested by calling the corresponding interface. The benefit of this approach is that nearly every function of an application can be checked directly. However, it entails problems as well. One of them is that the process flow must be complied with when calling sub-functions. A complete coverage is also difficult to achieve.

Grey Box Testing

Grey box tests seek to combine the benefits of black box and white box tests and to create test situations


While the graphics and text of these statuses can be illustrated in a user-friendly and generally understand-able fashion for category 2 (full HMI), determining the statuses of category 1 charging columns (reduced HMI) is difficult for the user. The seven statuses are only indicated by a light code that differs in colour and timing. Based on experience gathered in the e-roam-ing showcase, it is recommended to use the following guidelines:

As with a traffic light, green should always signal a positive feedback, red a negative feedback, and yellow an intermediate or "warning" status. In addition, the frequency pulse of the light can switch between per-manent on, on/off (blinking), and pulsating. Pulsat-ing means the light intensity oscillates sinusoidally without completely going out. The combination of the colour of the light and the frequency pulse results in the status displays illustrated in figure 13.

Irrespective of a visual marking of the reader, the user must be able to distinguish between seven statuses when operating a charging column:

▪ The charging column is available

▪ The charging column is blocked

▪ The charging column has recognised the RFID card

▪ The charging column is verifying the RFID card authorisation (at the back-end)

▪ Authorisation successful15

▪ Authorisation rejected

▪ The charging column is charging / electricity is being transferred

figure 12: Schematic diagram of the categories of user interfaces for charging columns in the e-roam-ing showcase 14.

category 1reduced HMI

LEDTouch-screen

RFID-Reader

RFID-Reader

category 2full HMI

category 3HMI without hardware

14 The figure shows an RFID reader in order to emphasise how important it is to label it. For remote access without an RFID card (see p. 19 ff.), however, the same recommendations for displaying the statuses apply.

15 For category 2 (full HMI), it would be helpful in this situation to display price information about the e-roaming process for the user on the screen.


In addition, the e-roaming showcase used charging columns with only a monochrome LED, referred to as reduced category 1. In this case, the statuses can only be coded via the frequency pulse, which results in the following displays (see figure 14).

Generally, the same colours as for category 1 can be used for the remote activation of category 3 charging columns (see figure 15)). In this case, however, it is recommended to only use the colour signals at the column for positive feedback, while indicating nega-

figure 13: Suggested status display at category 1 charging columns using red, yellow, and green LEDs.

START TARGET

STEADY GREEN LIGHT Read in RFID connect

plug

charging completedtimeout

Read in RFID

"external" process at back-end

STATUS:charging column available

STEADY RED LIGHT

STATUS:charging column blocked

BLINKING GREEN LIGHT

STATUS:authorisation successful

PULSATING GREEN LIGHT

STATUS:electricity being

transferred

PULSATING YELLOW LIGHT

STATUS:authorisation being verified

4 X BLINKING RED LIGHT

STATUS:authorisation rejected

BLINKING YELLOW LIGHT

STATUS:RFID recognised

RFID-reader

LED

RFID-reader

LED

RFID-reader

LED

RFID-reader

LED

RFID-reader

LED

RFID-reader

LED

RFID-reader

LED


Non-functional Requirements and Service Quality

The following section contains more information on non-functional requirements for e-roaming platforms

tive feedback via the HMI of the remote device, e. g. a smartphone (see figure 16). Otherwise, potential delay between an action on the user's smartphone and the corresponding display at the column might result in inconsistent perception of the colour signal.

figure 14: Suggested status display at category 1 charging columns using only a monochrome LED

START TARGET

STEADY LIGHT Read in RFID connect

plug

charging completed

timeout

Read inRFID



PERMANENTLY OFF


BLINKING SLOW FREQUENCY = 0.5


STATUS:electricity being transferred

PULSATING MEDIUM FREQUENCY = 1

STATUS:authorisationbeing verified

4 X BLINKING FAST FREQUENCY = 2

STATUS:authorisation rejected

BLINKING MEDIUM FREQUENCY = 1

STATUS:RFID recognised

OFF 4 SECONDS

STATUS:Reset

PULSATING

RFID-reader

LED

RFID-reader

LED

RFID-reader

LED

RFID-reader

LED

RFID-reader

LED

RFID-reader

LED

RFID-reader

LED

RFID-reader

LED


in order to present the experience gathered during the showcase inter-connection project and to make it available to potential partners on the market.

Secure and Flexible Platforms Have Proven Successful

Every roaming platform is an IT system with strict requirements regarding availability and security due to the data exchange process it is supposed to facilitate. For

figure 15: Remote activation of a charging column via smartphone app with successful authorisation

START TARGET

STEADY GREEN LIGHT Read inRFID connect

plug

charging completedtimeout

Read inRFID

feedback"authorisation

successful"

activation for user N

authorisation requestvia smartphone



STEADY RED LIGHT


BLINKING GREEN LIGHT


PULSATING GREEN LIGHT

STATUS:electricity being transferred

RFID-reader

LED

RFID-reader

LED

RFID-reader

LED

RFID-reader

LED

CLOUD

2a

1

2b


this reason, its entire IT infrastructure must at all times ensure a high security level as well as an excellent service quality and be brought in line with both current and foreseeable requirements. It is helpful and reasonable to use a scalable and modular layout in order to be able to

quickly adapt it to future requirements. For example, the T-Systems platform has an enterprise service bus, which can be used to conveniently implement different proto-cols on external platforms and new internal modules and data exchange processes at the same time.

figure 16: Remote activation of a charging column via smartphone app with rejected authorisation

START TARGET

Read inRFID

Read inRFID

feedback"authorisation

successful"

authorisation requestvia smartphone

CLOUD

1

STEADY GREEN LIGHT



STEADY RED LIGHT


RFID-reader

LED

RFID-reader

LED

2


Data Exchange Processes Should be Ad-hoc

Quick response times of the platforms are essential for the data exchange processes necessary between the e-roaming providers. The figure and the table on the next page illustrate a typical remote authorisation pro-cess and show why quick response times are necessary and why timeouts are required when defined intervals are exceeded.

The duration of process steps 1 to 4 is equal to the user's waiting time. The following example shows that highly available and efficient systems are indispensa-ble for this very reason: Even if each step merely takes a second, the user faces an overall waiting time of 11 seconds from his registration at a charging station until he receives a response on his app. In reality, however, runtimes are usually even longer because, as

Systems Must Be Robust

Robustness means that communication processes between systems are not stopped even if errors occur. Regardless of missing optional data or minor errors, the process steps should be continued. To this end, it is recommended to check the syntax upon the initial data transfer and to subsequently define common error descriptions with all parties involved to en-sure that both positive and negative results can be processed. This enables, for example, an incorrectly entered EVSE ID to be detected by a syntax check or a syntactically correct EVSE ID to be included in the communication process as the appropriate response to the relevant error code. The table below shows possible error codes from the OICP protocol which were used for communication between the platforms of T-Systems and Hubject.

Option Description Area of usage

000 Success. General codes

021 System error. General codes

022 Data error. General codes

103 RFID Authentication failed – card not readable. Authentication codes

105 PLC Authentication failed - invalid EVCOID. Authentication codes

210 No valid contract. Session codes

510 No EV connected to EVSE. EVSE codes

601 EVSE reserved. EVSE codes

602 EVSE already in use / wrong token. EVSE codes

603 Unknown EVSE ID. EVSE codes

700 EVSE out of service. EVSE codes16

16 Source: OICP protocol version 1.2, p. 66, CodeType (list of error and status codes), Hubject GmbH www.hubject.com.


a rule, one second per step is rarely reached due to bad connections or temporary network overloads.

This example shows a rather idealised runtime of 11 seconds.

Support Processes are Helpful and Customer-friendly

The cooperation between the various platforms of the showcase initiative also showed that access to an interconnected charging infrastructure becomes even more customer-friendly if B2B support processes are available. In this case, the partner can rely on a knowl-edgeable contact person on the part of his e-roaming provider and request support if problems occur. Based on the experience drawn from the showcase, efficient support processes should offer the following cascading service stages:

1. Provision of a service desk at each platform at least five days per week for eight hours daily

2. Provision of a service desk at each platform seven days per week for 24 hours daily

3. Access to the platform for service desk personnel for faster error analysis

4. Provision of suitable remote tools for the remote activation of roaming checking processes

5. Provision of proactive information on errors in own system for all market partners

Total system runtimes:

1 1 second

2a + 1 second

+ 1 second for processing by EMP system

2b + 1 second

+ 1 second for processing by roaming system

3a + 1 second

+ 1 second for processing by CPO system

3b + 1 second for processing

+ 1 second for processing by roaming system

4 + 1 second

figure 17: eRoamingMobileAuthorizeStart 17.

eRoamingEvseDataRecord

eRoamingMobileAuthorizeStart eRoamingAuthorizeStart

eRoamingAuthorizationStart

eRoamingGetEvseByld

Mobile App Hubject Brokering System EMP CPO

2b

2a

3b

3a

11

44eRoamingMobileAuthorizationStart

17 Source: OICP protocol Hubject GmbH, figures added to illustration.

Good E-Roaming Practice Additional Use Cases 33

Blocking Charging Columns

The Lower Saxony showcase implemented the "Block-ing" use case, in addition to providing information on the current status of a charging column and the option to activate it on site. "Blocking" means that a charging column is blocked for other users for 15 minutes, starting at a point in time called "Now". "Reserving" means that a charging column will be blocked for other users starting at a point in time in the future called "t1" (see figure 18).

Along with the use cases described above, which are directly linked to the charging process, ideas for more use cases came up while preparing for the e-roaming showcase. These ideas are presented below, followed by a discussion as to whether it makes more sense to extend existing protocols to this end or to develop a generic interoperation protocol for different services (see "Protocol Implications of Additional Use Cases" on p. 34 ff.).

Additional Use Cases

figure 18: Illustration of the difference between "Blocking" and "Reserving" a charging column.

now + 15 minutes [time]

now

CHARGING COLUMN RESERVED FOR USER

CHARGING COLUMN BLOCKED FOR USER

BLOCKING:

RESERVING:

future point in time t [time]

34 Good E-Roaming Practice Additional Use Cases

▪ Reading an authorisation media (e. g. an RFID card) into the technical infrastructure (barrier or charging column)

▪ Sending a verification request for this authorisation media into the "cloud"

▪ Activating the technical infrastructure upon a posi-tive response to the verification request

▪ Sending a service detail record to acknowledge the process if necessary

Reservations are also easier to implement when access to parking space with a charging infrastructure is restricted. This is because it is easier to ensure that at a certain future point in time all preceding charging pro-cesses will have been completed and the area in front of the charging column will be free, than is possible in the public domain.

One possible scenario could be to make a reserva-tion request to the pool that contains all existing charging points in a car park instead of reserving a specific charging point and to assign the concrete point shortly before it is needed, for example, when entering the car park. Similar to the way some airlines make seat reservations, empirical data could be used to determine when access to a charging point must be blocked to retain the existing reservation of a user. This scenario is illustrated in figures 19 and 20. Such a reservation system would, of course, have to be capable of roaming.

Protocol Implications of Additional Use Cases

The additional use cases described above have implica-tions for a possible inter-roaming protocol. On the one hand, the processes are very similar across different

The additional "Blocking" use case makes sense when looking at the special characteristics of the public infrastructure. In order for a charging column to be reserved at a future point in time t1, any preceding charging processes must have been reliably completed by then so that the column is indeed available. Howev-er, guaranteeing this availability involves a lot of effort for the provider of the charging infrastructure .

Blocking, in contrast, can be of great value for the user, for example, when his smartphone indicates that a nearby charging column is currently available. Now he can quickly reserve it for himself for 15 minutes, thus blocking all other potential users. Of course, even in this situation the user cannot be sure that the adjacent parking space is free. He knows, however, that in the meantime no other electric vehicle can start a charg-ing process which could last for several hours. In a roaming network, such a functionality would also be appealing between networks of different providers.

Opening Barriers and Reserving Parking Spaces

Access restrictions like barriers at the entrances to car parks are possible, particularly in a semi-public charg-ing infrastructure, i. e. when private providers install charging columns for public use on private property. In a roaming network, however, a convenient function to overcome such access restrictions would be help-ful, along with the possibility to activate the charging column. This would require some type of connection between the barrier and the roaming system and/or the software of the charging column. This is not easy since, for these cases, there are currently no indus-try-wide standards in place.

From a logical point of view, however, releasing a barrier requires the same individual process steps as activating a charging column. These are:

Good E-Roaming Practice Additional Use Cases 35

domain and investing a lot of effort in the coordination between the various industries involved.

In summary, however, it must be clearly stated that the technical implementation is difficult, but possible. The actual challenge is the coordination between the participating players from the different industries. The showcase initiative has elegantly proved that, in princi-ple, this challenge can be mastered.

use cases. Thus, authorisation at any "mobility infra-structure" using a RFID card always includes infor-mation on the unique RFID ID of the user, the unique infrastructure identifier, and the unique identifier of the infrastructure provider. Initially, it does not matter whether the ID refers to a car park, a charging station or a vehicle used for car sharing. The same is true in the opposite case of a remote authorisation, where these identifiers are also required.

On the other hand, the detailed implementation is more complex. There is no agreement on common standards for the various IDs used in the different mobility regions, nor on the implications for interac-tion with the user. If an error occurs, it is helpful for the user to be given direct feedback, for example, if a charging station is briefly unable to accept author-isation requests because it is restarting. If this is to be made possible across mobility domains, all parties involved must have a unified or at least compatible error-handling scheme in place.

The different object models used in various mobility domains are another challenge. Normally, a car park cannot be described using the same properties as for a charging station. Even if this can be compensated to a certain extent by using only basic properties (like the position), data of good quality still depends on the details of the object to be described. Particularly important in this respect is the status (e. g. parking space available, charging station functioning), but also other details, such as colour and technical properties affecting the usability of the object (like the plug type).

Billing the use of an infrastructure also entails major challenges. For example, the business model "car shar-ing" has a wide array of billing models (based on the number of kilometres driven, the use of special zones or the duration of the journey). Charging processes, in contrast, are usually billed on the basis of the amount of electricity consumed. At this point in time, it seems that defining a protocol for these very different use cases is only possible using profound knowledge of the

36 Good E-Roaming Practice Additional Use Cases

figure 19: Idea of a pool reservation strategy for a charging infrastructure in areas with restricted access – positive example.

figure 20: Idea of a pool reservation strategy for a charging infrastructure in areas with restricted access – negative example.

19

20

POOL POOL

reservation for tn

t0 tn

reservation for tn

tn-2 tn-1

POOL POOL

Good E-Roaming Practice Recommendations Derived from the Initiative 37

Visual Markings of Charging Points

The user of a charging column needs two particular pieces of information: where exactly it is located and how to activate it.

Visually marking the column helps locate it, especially with inaccurate geodata. Since the charging columns currently existing on the market differ in shape and col-our, it is recommended to uniquely label either the area around the column or the column itself. The recommen-dation to use a legally safe labelling system was already set down in the NPE Progress Report 2014 (p. 54). Therefore, this topic will not be discussed here in detail.

The second labelling type, i. e. labelling the column, is more important for the e-roaming showcase anyway. It indicates how the column can be accessed and activat-ed. The debit card symbols used in the credit services sector, which indicate interoperability to the customer, can serve as a model (see figure 21)..

In the e-mobility sector, providers like e-clearing.net (see figure 22) and Hubject (see figure 23) pursue a similar approach, using a unique logo to visually indicate compatibility within their own charging infra-structure network.

The benefit of the intercharge logos of Hubject is an integrated QR code that contains information on the charging column like its EVSE ID and makes remote activation via smartphone app more convenient. How-ever, this is not an industry-wide approach, but still an individual solution.

The initiators and the participants of the e-roaming showcases consider it imperative to label charging col-

Cooperation between the e-roaming platforms in the framework of the showcase interconnection has not only led to the above results, but also created addition-al value. The showcase initiative has shaped a unified market understanding of the roles, responsibilities, and tasks related to e-roaming among most of the companies working in the field of electromobility in Germany.

Organisational and Contractual Aspects

The unified assignment, use, and administration of bijective IDs to identify charging points (EVSE ID), contracts with customers (contract ID), and market partners (operator ID and provider ID) in Germany is a major achievement that enables each player and object on the market to be bijectively identified.

The second step should be to work out joint defini-tions for minimum requirements in order to ensure unified and efficient access to charging infrastructures, including rules for the use of EVSE ID information, unified liability and warranty terms, and blueprints for roaming contracts. In this area, sweeping initiatives are under way in Germany18,, which can serve as the basis for marketable applications.

Ideally, the third step should be to develop and establish standard agreements for a further reduction of com-plexity on the market, in order to provide efficient and open market access for all players - on an open market. Standard agreements have proved successful in other industries (e. g. in the gas cooperation agreement).

Recommendations Derived from the Initiative

18 e. g. eClearing.net and the intercharge network.

38 Good E-Roaming Practice Recommendations Derived from the Initiative

umns with respect to their accessibility and interoper-ability, whereby the priority should be on the bijective association of a charging point to an EVSE ID. Other information on the provider (e. g. a logo indicating compatibility) may be helpful for the user, but are not indispensable.

figure 21: Electronic cash as a model for a compatibility symbol from the credit services sector.

figure 22: Visual mark of the e-clearing network.

figure 23: intercharge symbol with integrated QR code.

21 22 23

Good E-Roaming Practice Outlook 39

Within the promotional programme "Electromobility showcase", partners from all four showcase regions have shown that e-roaming across different regions and platforms is feasible. They were able to show that, at this point in time, it is already possible to cover long distances like the route from Stuttgart via Munich to Berlin electrically, using a single charging card. The partners of the e-roaming showcase over-came one of the major obstacles for electromobility by demonstrating that unified access to differing and previously incompatible charging infrastructures can be implemented. In doing so, they proactively adopted the requirements set down in the EU directive on the "Deployment of Alternative Fuels Infrastructure" and showed in a joint effort that an e-roaming solution complying with this directive is already viable. This achievement is also acknowledged in the current NPE report: "The current interconnection between the show-case projects shows that there are no technical obsta-cles for connections between roaming platforms."19

The e-roaming showcase used the two use cases "Find" and "Charge" to demonstrate how customers of differ-ent EMPs can find and use charging points through-out Germany. The experiences and insights gained in the process are reflected in this Practical Guide. It describes the framework conditions that need to be considered and the solutions that have proved to be good practice.

However, this is only the first step. Even though, in principle, a comprehensive e-roaming solution within and between the showcase regions is now in place and more and more bilateral roaming agreements are being concluded between the individual market players involved, these solutions as a whole are not yet stand-ardised, repeatedly requiring a considerable amount of

effort for coordination. On a European level, there are hardly any e-roaming solutions that go beyond bilater-al agreements. Therefore, the showcase initiative has spawned an all-European roaming initiative seeking to develop a unified European e-roaming solution.

However, there is still a long road ahead before all us-ers of e-vehicles can be provided with non-discriminat-ing access to charging points any time and anywhere in Europe. The purpose of this guide is to support both national and European initiatives on this path towards a unified e-roaming system by presenting a potential problem-solving approach for their current and future discussions.

Outlook

19 NPE Report 2014, page 31 ff.

40 Good E-Roaming Practice Appendix

Glossary

APP Application = software product for smartphones

Broadcast Similar to radio broadcasting. Denotes a technology used to send messages to all the recipients connected at the same time. Opposite terms: multicast (selected recipients only), unicast (a specific recipient).

CCS Combined Charging System

CDR Charge Detail Record (provides information on billing data on completed charging processes)

CEE CEE three-phase plug-in or push-on connector is the colloquial term used to refer to the most common IEC 60309 standard electrical connectors. In Europe, the normal usage includes red 400V three-phase con-nectors, whereas blue 230V connectors are used in camping.

Contract ID Contract number of a consumer during charging

CPO Charging Point Operator; see also Operator

EMA ID E-Mobility Account Identifier; see also Contract num-ber

EMP E-Mobility Provider

E-Roaming Provider Provider of an IT infrastructure designed to bring charg-ing point operators and mobility operators together

EVCO-ID Electric Vehicle Contract Identifier; see also Contract number

EVSE Electric Vehicle Supply Equipment = charging point

EVSE ID Electric Vehicle Supply Equipment Identifier = charg-ing point identifier

GUID Global User ID = global reference ID

HMI Human Machine Interface

ICCB In Cable Control Box, control unit inside the charging cable of modern electric vehicles carrying out safety and communication functions when connected to the power grid

ICT Information and communication technology

ICT Platform Information and communication technology platform, promotional project 3.1 of the Lower Saxony showcase

JSON JavaScript Object Notation. Originally created to provide persistence for JavaScript objects. Currently widely used as a reduced data format in numerous web applications and particularly in mobile applications (apps). Is also used without JavaScript implemen-tation. Today, it often competes against XML-based data formats even though it is designed for completely different use cases.

mTAN Mobile Transaction Number

Appendix

Good E-Roaming Practice Appendix 41

RFID Denotes the technology used by sender receiver sys-tems for the automatic and contact-free identification and localisation of objects by means of radio waves.

An RFID system consists of a transponder, which is at-tached to an object or a living creature and contains an identifying code, as well as reading device to readout this identifier.

Routing table Provides information about which participant is con-nected to which roaming platform.

SDR Service Detail Record

SOAP The SOAP protocol is a standard of the World Wide Web Consortium (W3C) for exchanging data via the internet. SOAP is no longer used as an acronym and is therefore the name of the method.

UID Unique Identifier

Contract number Contract number of a consumer during charging

NFC Near Field Communication

NPE National Platform Electromobility

NUID Non Unique Identifier

OCHP Open Clearing House Protocol

OCPP Open Charge Point Protocol

OICP Open Intercharge Protocol

Operator Charging Point Operator

Operator ID Charging Point Operator Identifier

OWL Web Ontology Language

POI Point of Interest

RDF Resource Description Framework

REST Stands for Representational State Transfer and is a method for the loca-tion-based access to data on the inter-net. Today, REST is often mixed with other methods like SOAP (for instance by describing methods for the access to web resources, which is contrary to the method definition).


Fortschrittsbericht 2014 –Bilanz der Marktvorberei-tung. (G. G. (GGEMO), editor) Berlin.

NXP Semiconductors. (03. 03 2014). MIFARE Classic EV1 1K – Mainstream contactless smart card IC for fast and easy solution development. Downloaded on 15.12.2014 from http://www.nxp.com/documents/data_sheet/MF1S50YYX_V1.pdf.

NXP Semiconductors. (21.12.2010). MIFARE DESFire EV1 contacless multi-application IC. Downloaded on 15.12.2014 from http://www.nxp.com/documents/short_data_sheet/MF3ICDX21_41_81_SDS.pdf.

OCHP Open Clearing House Protocol. (without date). Downloaded in December 2014 from OCHP Open Clearing House Protocol: http://www.ochp.eu/.

Open Charge Alliance. (08. 06 2012). Open Charge Point Protocol 1.5. Downloaded on 08. 12 2014 from http://www.openchargealliance.org/sites/default/files/ocpp_specification_1.5_final.pdf.

Bibliography

BDEW Bundesverband der Energie- und Wasser-wirtschaft e. V. (without date). Downloaded in Decem-ber 2014 from bdew-Elektromobilität: https://www.bdew.de/internet.nsf/id/DE_Elektromobilitaet.

BDEW Bundesverband der Energie- und Wasser-wirtschaft e. V. (without date). Downloaded in Decem-ber 2014 from the bdew-E-Mobility portal: https://bdew-emobility.de/.

DIN. (11 2011). DIN SPEC 91286. Downloaded from Elektromobilität – Schemata für Identifikatoren für E-Roaming – Contract ID und EVSE ID: http://www.spec.din.de/cmd?level=tpl-art-detailansicht&commit-teeid=0&artid=145915787&bcrumblevel=2&language-id=de.

Hubject GmbH. (without date). hubject – connecting emobility networks. Downloaded in December 2014 from hubject – connecting emobility networks: http://www.hubject.com.

ISO. (04 2014). ISO 15118-2 – Vehicle to grid commu-nication interface. Downloaded from Part 2 – Network and application protocol requirements: http://www.iso.org.

KEMA IEV – Ingenieurunternehmen für Energiever-sorgung GmbH. (2013). StromTicket. Downloaded on 08. 12. 2014 from Jetzt Strom tanken!: http://strom-ticket.de.

Nationale Plattform Elektromobilität (NPE). (Decem-ber 2014). Die Deutsche Normungs-Roadmap Elek-tromobilität – Version 3.0. (G. G. (GGEMO), editor) Berlin, Germany.

Nationale Plattform Elektromobilität (NPE). (De-cember 2014). Fortschrittsbericht 2014 – Bilanz der Marktvorbereitung. (G. G. (GGEMO), editor) Berlin, Germany.

Nationale Plattform Elektromobilität [NPE]. (2014).

Good E-Roaming Practice Appendix 43

Abbildung 01: Standardising the Charging Interface - Overview (National Platform Electromobility [NPE], 2014, p. 28). 6

Abbildung 02: Illustration of an authorisation process using an RFID card (Volkswagen mobility card, MoKa). In-house illustration. 8

Abbildung 03: Illustration of an authorisation process using an RFID card (ChargeNow card). In-house illustration. 9

Abbildung 04: Illustration of a search for a POI. In-house illustration. 10

Abbildung 05: Remote authorisation at a charging infrastructure via the intercharge platform. 11

Abbildung 06: Relevant Roles in E-Roaming (source from Green eMotion) 12

Abbildung 07: Simple model of a charging column with two charging points and four sockets. 14

Abbildung 08: Illustration of cooperation models for e-roaming. In-house illustration. 15

Abbildung 09: Multi-platform approach via bilateral connections. In-house illustration. 16

Abbildung 10: Multi-platform approach via routing tables and protocol adaptations. In-house illustration. 17

Abbildung 11: Multi-platform approach via routing tables and an inter-roaming protocol. In-house illustration. 18

Abbildung 12: Schematic diagram of the categories of user interfaces for charging columns in the e-roaming showcase. 26

Abbildung 13: Suggested status display at category 1 charging columns using red, yellow, and green LEDs. 27

Abbildung 14: Suggested status display at category 1 charging columns using only a monochrome LED 28

Abbildung 15: Remote activation of a charging column via smartphone app with successful authorisation 29

Abbildung 16: Remote activation of a charging column via smartphone app with rejected authorisation 30

Abbildung 17: eRoamingMobileAuthorizeStart. 32

Abbildung 18: Illustration of the difference between “Blocking” and “Reserving” a charging column. 33

Abbildung 19: Idea of a pool reservation strategy for a charging infrastructure in areas with restricted access – positive example. 36

Abbildung 20: Idea of a pool reservation strategy for a charging infrastructure in areas with restricted access – negative example. 36

Abbildung 21: Electronic cash as a model for a compatibility symbol from the credit services sector. 38

Abbildung 22: Visual mark of the e-clearing network. 38

Abbildung 23: intercharge symbol with integrated QR code. 38

List of illustrations


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EditorBegleit- und Wirkungsforschung Schaufenster Elektromobilität (BuW)

Deutsches Dialog Institut GmbHEschersheimer Landstraße 22360320 Frankfurt am MainPhone: +49 69 159003-0Fax: +49 69 759003-66info@buw-elektromobilitaet.dewww.schaufenster-elektromobilitaet.org

Contents, text, and editingPeter Christ (T-Systems)Christian Hahn (Hubject)Stefan Henze (Volkswagen)Tobias Hesse (DLR)Robert Kaul (DLR)Sebastian Kazubski (P3 Group)Sven Lierzer (BuW / bridgingIT)Peter Scholta (T-Systems)Michael Strasser (Bosch Software Innovations)Nico Weiner (Bosch Software Innovations)

Photos of people, cover photo, and other photosHubjectShutterstock.comT-Systems

Layout, composition, illustrationsMedien&Räume | Kerstin Gewalt Felgner & Zierke, Berlin

EditingWissenswort Joachim Pietzsch

Translated from German by:Roland Dilger

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