UPnP Compression Implementation for Building Automation Devices

IP based field bus networks enable the usage of common IP protocols for example for security or automatic configuration, on the field level. IP based devices can take advantage of the well-specified UPnP protocol for commissioning and operation. A drawback of this protocol deployment is the high required network bandwidth due to enormous high level protocol overhead, especially on the XML-and SOAP based UPnP schemes. We investigate UPnP datagram size reduction on an experimental IP based field bus with Ethernet and wireless IEEE802.15.4 devices, for building automation and control applications. To be able to use standard unmodified UPnP stacks, we use transparent bidirectional XML/SOAP proxies for example on the Ethernet/IEE802.15.4 hub and on the wireless devices itself. The proxy uses cache-based tokenizing of the SOAP messages and feedback, typically deflating subsequent similar messages by orders of magnitude, thereby significantly reducing the number of data packets and increasing the network performance especially when using IEEE802.15.4 as wireless physical layer.