Paper presentation at IEEE International World Forum on Internet of Things in Seoul, South Korea, March 6-8

The paper presentation at the IEEE International World Forum on Internet of Things was a good opportunity to present first research results. I presented my work in a short paper session with an additional poster session and interesting discussions arise within the scientific community.

Conference Venue

Poster session

Poster session

Beside the conference visit, I had also the opportunity to visit the smart city district Songdo, Incheon. It shows how the buzzword "smart city" can become implemented and reality. More than 1.000 sensors and more than 100 cameras allow to address different domains (traffic, safety, security, environmental, ...). An impressive public control center allows to manage the public domain of the smart city district.

Songdo Smart City District - Incheon, South Korea

Songdo - Smart City Control Center

Songdo - Smart City Control Center

Cisco - Smart City Control Center Show Case

Finally, there was also some time left to explore the interesting cultural aspects of Korea.

Korea National Museum

Korean Tombs + Temples

Group communication with OBIX for the Internet of Things and a scripting-free control logic editor: paper accepted at WF-IoT2014

Based on the communication stack presented in the previous post it is possible to design a process data exchange that can be compared to KNX in which a group communication is used to denote a shared network variable that allows a group of devices to exchange process data. By doing so it is possible to create a simple control logic editor that wires together the basic data points of OBIX objects which represent physical devices or control logic objects.

Group communication and scripting-free control logic editor with IoTSyS

Details on the group communication approach can be found within the paper:

Markus Jung and Wolfgang Kastner. Efficient group communication based on Web services for reliable control in wireless automation. In Proceedings of the 39th Annual Conference of the IEEE Industrial Electronics Society, Vienna, Austria, November 2013

The scripting-free control logic editor will be presented within a poster session at the upcoming IEEE World Forum on the Internet of Things, which will take place in Seoul, South Korea in March 2013. It is the first paper that emerged within the scholarsihp period and the support of the IPA is well-acknowledged in the last section of the paper:

Markus Jung, Esad Hajdarevic, Wolfgang Kastner, Antonio J. Jara. Short Paper: A Scripting-Free Control Logic Editor for the Internet of Things. In Proceedings of the IEEE World Forum on Internet of Things, Seoul, Rebublic of Korea, March 2014. To appear.

The prototype implementation of the group communication and the scripting-free control logic editor are provided already in the open source project.

Integration concept for heterogeneous home and building automation technologies

A variety of home and building automation technologies are currently in use in state of the art home and buildings and will be use for the next decades. The technologies are either scoped on certain domains of automation (e.g. lighting, shading, HVAC, security, safety, ...) or focus on specific geographically separated markets (e.g. Europe or North America).

Important technologies to be mentioned here are for example KNX, LonWorks, BACnet, ZigBee, Z-Wave or EnOcean.  KNX is an important European home and building automation standard that is mainly used in the field level of a automation control network and a huge variety of devices and products exists. On the same level LonWorks provides similar features but has a higher market share in the North American marekt. BACnet on the other hand is an open standard that is mainly used in the automation level of a control network and is mainly in use for commercial building automation technologies. ZigBee is an open wireless standard that mainly focuses on wireless sensor networks and home automation. Another wireless standard for home automation is EnOcean, which recently gains more importance, since it uses energy harvesting for collecting the required energy to operate the automation devices. Z-Wave is a popular but closed standard that operates in a similar environment like ZigBee.

The huge heterogeneity of technologies is an inhibitor for the successful deployment of home and building energy management systems, which are an essential component for optimizing the energy consumption of a building and further for future interaction patterns found in smart grids or smart cities. In this domain also new protocols emerge like for example (Wireless) MBus that can be used to communicate with smart meters.

All these technologies come with a different system stack. For example, custom physical, data link, network, transport, session and application layers. In order to make them interoperable gateways are required that map the different communication principles of the different layers. For the integration a mapping can be provided either for each possible communication pair, or a single integration technology is chosen to which all other technologies are mapped.

Integration approaches

The single technology integration approach is desirable since the complexity and the efforts can be reduced. The question is now which technology stack should be used for the integration. A strong trend in research and industry aims at using standard and mature Internet and IT technologies for the integration but also for new devices directly on the level of sensors and actuators.

So an integration based on an communication stack using IPv6 is desirable and for constrained wireless sensor networks 6LoWPAN can be an enabler to efficiently operate IPv6 even on most contrained wireless devices. Just a new application protocol would be not sufficient. Instead a complete system stack (so-called IoTSyS stack) is required that can be used to operate the Internet of Things and to provide interoperability amongst heterogeneous technologies. 

Integration challenge

For providing the upper layer technologies different protocols can be used and a communication based on Web service communication (HTTP + XML) is desirable due to the huge success within IT system integration. However, due to the resource demand (CPU, memorgy, bandwidth) these technologies are not suitable for a deployment in a constrained (wireless) control network with constrained nodes. Therefore, optimizations like the Constrained Application Protocol (CoAP) and Efficient XML Interchange (EXI) can be used to optimize the resource demand of these technologies and to make a deployment feasible. Finally, the application layer semantics need to be mapped into the communication stack. For home and building automation technologies BACnet/WS, OASIS Open Building Information Exchange (OBIX) and OPC UA provide the required information models to provide a common view on building automation systems. Due to the RESTful design of OBIX, which fits very well to the mapping of data point oriented automation systems, OBIX is chosen for providing the application layer semantics.

The final system stack can be seen below.

IoTSyS system stack

Within the scope of the research activities and the thesis novel protocol bindings to CoAP/EXI have been contributed to the OASIS specification.

For the creation of a gateway software that maps the different technologies the Java platform is chosen and the OSGI runtime environment in order to use a component-oriented software design.

Integration gateway design

The gateway uses so call protocol-bundles or drivers for direct communication with bus systems. For this purpose, new drivers have been developed (e.g. W-MBus) or existing open source libraries (e.g. Calimero for KNX, BACnet4J for BACnet,...) have been reused. Then, a common object model based on OBIX is mapped to these technologies and provides the representation of the different systems for the Web service based communication interfaces and for internal services.

A proof of concept implementation for an integration gateway is provided at the project repository (http://code.google.com/p/iotsys).

More details about this approach can be found within the papers:

Markus Jung, Jürgen Weidinger, Christian Reinisch, Wolfgang Kastner, Cedric Crettaz, Alex Olivieri, and Yann Bocchi. A transparent IPv6 multi-protocol gateway to integrate Building Automation Systems in the Internet of Things. In Proceedings of the IEEE International Conference on Internet of Things (iThings 2012), Besancon, France, November 2012

Markus Jung, Jürgen Weidinger, and Wolfgang Kastner. A seamless integration of KNX into Constrained RESTful Environments. In Proceedings of the KNX Scientific, Las Palmas, Spain, November 2012

Markus Jung, Jürgen Weidinger, Wolfgang Kastner, and Alex Olivieri. Building automation and smart cities: An integration approach based on a service-oriented architecture. InProceedings of the 27th IEEE International Conference on Advanced Information Networking and Applications, Barcelona, Spain, March 2013.

This blog will document my work on my PhD thesis on a communication stack and integration middleware for the Internet of Things which is supported by a scholarship of the Internet Foundation Austria within the netidee 2013 programme. Resulting open source code will be published within the IoTSyS open source project  using the BSD 3 clause license.

A communication stack and integration middleware for the Internet of Things

The successful realization of smart grids or smart cities requires the integration and interconnection of buildings, being responsible for about 23% of the world-wide electricity consumption. Interoperability is a key challenge, since state of the art building automation systems are not compatible with each other and not designed to scale for a such large scale systems. The use of IP communcation can be a key enabler to this problem having smart grids and smart cities as first applications of an Internet of Things. The focus of this thesis is the design of a novel system protocol stack for the Internet of Things that should mainly rely on open Internet and Web protocols. Furthermore, an integration concept for existing building automation system should be created and the proposed system should be evaluated regarding security, privacy and scalability implications.

State of the Art

Research towards the use of IP communication and Web technologies for building automation systems focuses typically only on a certain layer of the communication stack and came up with protocols like 6LoWPAN or ZigBee/IP. However, the use of IPv6 only provides a common network layer. The transport and application layers are left out of scope. Current research proposes to apply state of the art Web service technologies to provide interoperable message exchange protocols. Due to the high resource demands several optimizations are required which resulted in the standardization of the Constrained Application Protocol and Efficient XML Interchange. However, the recent research results do not provide a holistic systems stack and the application layer semantics and information models are missing. The large scale interconnection leads further to scalability problems and interconnection of homes and buildings to strong privacy concerns which are still a hot research topic.

Aims of the thesis

1. To design a holistic system stack and integration middleware for the Internet of Things. 
2. The system stack should be based as much as possible on existing Internet and Web technologies but optimized to be deployable on constrained sensor and actuator nodes operating with limited resources (memory, CPU, bandwith).
3. For the creation of the stack the requirements and communication features of existing building automation system technologies should be analyzed in order to be applicable in the building automation domain. 
4. Further an integration concept and integration middleware should be designed relevant state of the art technologies (KNX, BACnet, W-MBus). v) Strong access control and authorization mechanisms should be an integral part of the system stack. Privacy concers could be a strong inhibitor for the success of the Internet of Things.
5. The system limits regarding scalability of the system should be analyzed by means of analytic methods and protocol simulation.