Ethernet
The general technology trend is for everything to become part of a node on a
cabled or wireless Ethernet network and have an IP address. This is the digital
convergence trend we have already witnessed and will continue to see for years
to come.
In the data telecommunications arena IP and Ethernet have been standards
for years. Voice communications, traditionally modeled after legacy mono-
lithic mainframe computers, are quickly moving to the data telecommunica-
tions world via voice over IP (VoIP). Video is also moving to digital
communication protocols. Building automation systems have specific industry
protocols (BACnet, LonTalk and others), but they too are moving to convert
or interface the protocols to the universal, dominant IP protocol.
Life safety systems still lag somewhat, video surveillance systems have
moved to IP, and access control is moving in that direction as well. Even leg-
acy systems with proprietary standards can have protocols converted or trans-
lated to the standard IP protocols.
XML and SOAP
EXtensible Markup Language (XML) is a structure for storing data in a plain
text format and transporting the data. XML is important for smart buildings
because it is independent of hardware and software and is the most common
method for transmitting data between system applications. It normalizes and
standardizes data and facilitates the integration of systems and system data-
bases that may contain data in incompatible formats.
For example, you can take security credentials data from a Structured Query
Language (SQL) database for access control, convert the data to XML, then
share the data with a human resources or student record application; this would
allow security credentials to be created or deleted as employees or students move
in and out of the organization without the need to coordinate and duplicate
the actions in both databases. In addition, a very large number of international
programmers and software vendors have adopted XML.
The XML data are “wrapped” in tags that are specific to the application.
Tags are created by a programmer to send, receive, or display the data. Unlike
HTML, which formats and displays data, XML has no predefined tags.
Whereas XML formats data, the Simple Object Access Protocol (SOAP) is
used to communicate that data between applications. SOAP is a communications
The Foundations of a Smart Building 21