Study on integration technologies of building automation systems based on web services

At present, there are three kinds of difficult integration problems in building automation systems. One is the integration between building automation systems (BAS) and existing enterprise applications. The second is the integration of building automation systems which adopt different international standardized protocols (e.g. BACnet or LonTalk). The third is the integration of building automation subsystems (e.g. HVAC control, lighting control or fire alarming). The ldquointelligencerdquo of intelligent buildings is still more of a promise than a reality. Web Services, defined as self-contained, modular software components that can be described, published, located and invoked over the Internet using existing IT standards creates a new wave of evolution and pushes BAS industry into a new paradigm. Web Services provide new solutions to overcome above problems. The paper analyses the development procedures and current problems of the BAS industry, proposes that Web Services based on XML, SOAP, WSDL and UDDI are the best answer in solving the integration problems of building automation systems. The paper also describes integration technologies, framework model and realization principles of BAS based on Web Services.