Christian Reinisch

Wireless Technologies in Home and Building Automation

The use of wireless technologies in automation systems offers attractive benefits, but introduces a number of new technological challenges. The paper discusses these aspects for home and building automation applications. Relevant standards are surveyed. A wireless extension to KNX/EIB based on tunnelling over IEEE 802.15.4 is presented. The design emulates the properties of the KNX/EIB wired medium via wireless communication, allowing a seamless extension. Furthermore, it is geared towards zero-configuration and supports the easy integration of protocol security.

Integration of heterogeneous building automation systems using ontologies

The challenge of integrating heterogeneous systems in order to combine their functionality is of utmost importance for the further deployment of building automation systems. The goal is to allow comprehensive communication among the systems. This will provide enhanced possibilities thus making way for intelligent buildings. Traditionally, integration is achieved using gateways which require considerable configuration effort. To alleviate this overhead and provide a unified system view, a generic application model is proposed that can accommodate all functionality found in building automation systems. The employment of this model promises several benefits such as a central point for configuration and system access. The method of choice are ontologies, which allow to offer a seminal representation of knowledge, an abstraction of the heterogeneous network infrastructure and automatic reasoning on the stored knowledge.

A Transparent IPv6 Multi-protocol Gateway to Integrate Building Automation Systems in the Internet of Things

The future Internet of Things (IoT) should enable machine-to-machine interaction for devices out of numerous domains. Recent developments and standards focus on how to deploy IP directly on devices and investigate application protocols that fit the constrained environments, whereas research on the integration of widely deployed legacy devices of technologies like BACnet, Lon Works and KNX is still neglected. For a success of the ambitions towards an IoT we identify it of highest importance to research various integration styles for non-IP based devices already deployed in home and building automation. Therefore, this paper contributes an overview of various possible integration styles, provides a concrete multi-protocol integration architecture and presents evaluation results of a proof of concept implementation.

Integrating Building Automation Systems and IPv6 in the Internet of Things

The vision of the Internet of Things is a seamless integration of diverse physical objects in the Internet through a virtual representation. In recent years, the target area of IoT constantly broadened from products within supply chains and nowadays encompasses all objects that are summarized under the label of ubiquitous and pervasive computing. Therefore also building automation devices are considered for an integration in the IoT, where they are for example used to realize a smart and sustainable building operation. Ubiquitous access to the objects is facilitated by the concept of building automation systems (BAS) that already provide a virtual representation of physical objects, mainly sensors, actuators and control devices. In practice, BAS follow a layered system architecture which defines a management, an automation and a field tier. In the field tier, non-IP communication based on twisted pair, power line or radio frequency technologies is prevalent. For the backbone infrastructure at the automation and management tier, IPv4 has become the de-facto standard. At this level, the transition towards IPv6 is the most promising technology to enable the full realization of the Internet of Things vision. New features like the larger address space, self-configuration, quality of service mechanisms and security promise a better integration of building automation technology in the IoT. Therefore this article investigates the readiness and compatibility of existing BAS technologies with IPv6. The integration challenges and new opportunities of IPv6 for these technologies are presented. Furthermore, possible integration scenarios for IPv6 using BAC net as example use case are sketched.

ThinkHome: A smart home as digital ecosystem

Smart homes have become increasingly popular in the past few years. Similarly, new buildings are nowadays planned and built following sustainability guidelines. Energy efficient residential homes have gained importance for two reasons. They contribute to the protection of our environment and they simultaneously reduce operational costs over the whole building lifecycle. However, the full potential of smart homes still lies fallow due to the high complexity of the underlying automation systems as well as the physical processes that are to be controlled. This is the motivation to review smart homes under a digital ecosystem perspective. With respect to this viewpoint, this paper proposes a system concept that applies artificial intelligence in smart homes. Main goals are to minimize energy consumption while at the same time guaranteeing user comfort. Therefore, intelligent control strategies are developed that take a multitude of parameters into consideration and operate automatically. For this purpose, an agent part populated by a society of autonomous agents that implement artificial intelligence is developed. It is supported by an ontology based knowledge representation that contains all relevant data in a structured way.

Denial-of-service in automation systems

Security aspects of todaypsilas automation systems gain increasing importance. One critical point regarding security is the exchange of control data over the network. Recently, cryptographic techniques have been developed that can protect the transmitted data against a malicious interference. However, there are security threats which cannot be prevented using cryptographic techniques. Typical representatives are denial-of-service (DoS) attacks. Therefore, this paper presents a novel, generic approach how such DoS attacks can be prevented or, if prevention is not possible, can be detected at least.

Key set management in networked building automation systems using multiple key servers

With the integration of security critical applications into traditional building automation systems, a comprehensive security concept is mandatory. Most important, transmitted data have to be secured using cryptographic techniques. However, even if the used cryptographic algorithms are perfectly secure, the overall security highly depends on the non-disclosure of the used shared secrets. Therefore, this paper targets the management of these shared secrets and the necessary infrastructure used to manage them. Finally, to eliminate a single point of failure in this infrastructure, a redundancy concept featuring multiple key servers is presented.

Gateway-free integration of BACnet and KNX using multi-protocol devices

Today, building automation systems can be realized using a multitude of different standards. Since each of these standards has its benefits, the combination of different standards and consequently of their best features promises substantial synergies. However, an integration is far from being straight forward and thus demands research. Starting from an analysis of the benefits that integrated building automation networks can offer, this work reviews the different approaches to combine KNX and BACnet. A gateway-free solution based on multi-protocol devices is considered most promising and examined in detail. The required protocol adaptations are discussed and, finally, a prototype implementation of an integrated, gateway-free BACnet/KNX internetwork is presented.

Agent based control in the Smart Home

The term Smart Home promises an energy efficient and comfort oriented operation of buildings. While the technical foundations have mostly been laid (e.g. integration of entertainment devices), also the complexity of the systems reached a peak level. Users find it hard to understand their systems and, worse, to tailor them to their individual needs. At the bottom line, smart homes therefore often fail to exploit all their potentials, among others due to non-optimized control strategies, frequent manual comfort overrides or simple user dissatisfaction. In this paper agent based systems are applied to control a smart home, with the main reason to exploit built-in intelligence and autonomous operation capabilities to tackle the existing shortcomings. In particular, it is shown how agent characteristics such as goal drivenness, robustness and learning capable behavior complement a smart home control system. Further focus is put on describing the complete process from selection of the most suited agent approach for smart homes to detailing the transition from system specification to implementation.

Multicast communication in wireless home and building automation: ZigBee and DCMP

With an ever increasing performance, wireless technologies present a more and more attractive alternative to wired media. This is also true for home and building automation (HBA) systems. In HBA, large areas must be covered at low cost. This precludes the use of dedicated network infrastructure. At the same time, the allowable power consumption and thus transmission power of sensors in particular is severely restricted. Hence, efficient peer-to-peer communication schemes are required. Especially for multicast communication, optimized protocols can make a difference. Therefore, this paper shows how DCMP (dynamic core based multicast routing protocol for ad hoc wireless networks) can be used to improve multicast in ZigBee networks.