wilamowski-b-m-irwin-j-d-industrial-communication-systems-2011

Building and Home Automation 26-9
that special attention is devoted to the usability of the system as such, its user interfaces, and all controls
visible to the residents. The design must focus on a broad target group of different ages and (technical)
skills, as user friendliness is crucial for the acceptance of any such system. During regular operation, the
user involvement must also be guaranteed. The users must retain full control of their systems that therefore
have to offer sufficient degrees of freedom in controlling. While certain tasks may happen without
intervention (i.e., automatically), it is important that the system remains transparent to the user, does
not behave unexpectedly, and allows for the user to choose his preferences and—if desired—overrule
the system at any time.
During system operation, data is collected, processed, and exchanged over a communication network.
These data may consist of personal information on user preferences, activities, and details on the home
and its equipment. Clearly, knowledge of this information would provide a global system view and
allow backtracking of the behavior of its residents, if misused in such a way. Therefore, systems must be
designed with privacy in mind and permanently allow the user to decide which information to share and
which parts to keep secret. Modern HAS may also be accessible via remote or mobile terminals, (Web)
gateways, or even use unsecured communication media for data exchange. This raises the question of
security in communication that is required to keep sensitive, personal information confidential and that
prevents abuse of the system for economic or even life safety reasons. Last, but not least, the economic
dimension in the residential sector must not be underestimated. The residential market is very sensitive
to the price of any equipment, so home automation products need to have a return on investment within
a few years after installation time. This return on investment can, for example, be yielded by increased
energy efficiency.
26.3.2 technologies and Integration Aspects
Apart from the big (protocol) players in building automation (i.e., BACnet, KNX, and LonWorks),
several other protocols have emerged that specifically target the home automation market. Their common
denominator is the support and focus on applications pertaining to the home domain. The special
requirements of home automation are targeted and reflected in the protocol design.
With HomePlug [17], the HomePlug Powerline Alliance proposes a protocol that enables and promotes
rapid availability, adoption, and implementation of cost-effective, interoperable, and standards-based
home powerline networks and products. Communication channels are the almost ubiquitous powerlines,
which in general are ready to use as basic infrastructure. The underlying powerline communication standard
allows for all aspects of powerline communication. Device interconnection with lower data rates
is established using the HomePlug 1.0 protocol, while high data rate multimedia streaming and VoIP
services are provided by HomePlug-AV. Traditional home automation applications are realized by a lowcost,
low data-rate branch called HomePlug Command & Control. With HomePlug Access BPL, a broadband
powerline technology intended to provide to-the-home access (i.e., bridging the “last mile”) has also
been specified. Together with the ZigBee alliance, the HomePlug alliance has formed a working group
in order to devise high-level protocol specifications to be used on both powerline and wireless systems.
The approach of the upcoming digitalSTROM [13] standard is to control electrical home equipment
through core components called “luster terminals.” These consist of a high-voltage chip located directly
at the end device or appliance. A novelty is the dual use of the chip, which, on the one hand, acts as an
actuator (e.g., switching, dimming) and, on the other hand, as a sensor that can at least roughly measure
the energy consumption. Installed in the fuse box is the “meter” device that controls the terminals
and accurately measures power on a circuit. Additionally, an interface to a Web server is provided that
records energy information from sensors, controls terminals through the meter, and provides information
visualization. DigitalStrom therefore provides very low-rate powerline communication and features
such as energy measurement, plug and play, and remote control.
Wireless systems with all their benefits (e.g., free placement, no additional wires) and challenges
(e.g., power consumption and supply, interference) are also on the rise [31]. This is partly not only due
© 2011 by Taylor and Francis Group, LLC