Interworking of presence protocols and service interfaces

Presence information represents the basis for context awareness and for building pervasive systems. This paper addresses design aspects in the inter-working between two important presence standards: IETF´S SIMPLE presence protocol and the OSA/Parlay presence and availability management APIs. We also consider a third alternative supposed to offer a presence Web service at a higher abstraction level: the new Parlay-X presence interface. This paper compares all three technologies, suggests a mapping between them and describes the overall architecture of the presence system we implemented at ftw., which integrates these three technologies.