A High-Performance Architecture of an XML Processor for SIP-Based Presence

With the widespread popularity of XML, many communication and multimedia standards are being developed based completely or partially on XML. The session initiation protocol is a signaling mechanism - frequently used for multimedia applications - that comprises XML-based ldquopresencerdquo information particularly useful in instance messaging.The process of XML parsing and serialization is needed repeatedly during the exchange of presence notification messages in such systems. However, XML processing is known to be time-consuming. In instant messaging systems, especially when mobile users are involved, presence update notification is frequent and has to be fast to save mobility time and battery resources. In this paper, we present a high-performance architecture of an XML processor customized for efficiently processing presence information. Our FPGA implementation results show that at least two bytes of XML data can be parsed on average in each clock cycle, which leads eventually to a high-throughput processor.