Copyright © 2006 Open Geospatial Consortium, Inc. All Rights Reserved.
29 If the service knows the given ID he will return the message in the response:
?xml version=1.0 encoding=UTF-8? GetMessageResponse
= http:www.opengis.netwns ..wns.xsd
sps:status New data available
Otherwise, he will issue an exception with code
8 Common notification mechanism
OGC provides many specifications for Web services that either provide data, the ability to gather data or to process data. With algorithms getting more complex and the amount
of data getting bigger we are faced with the problem that communication via HTTP i.e., sending a request and receiving the response can no longer be said to happen in a
synchronous way. We rather have reached the point where we need mechanisms for asynchronous communication between clients and Web services.
Given that we are using SOAP over HTTP we can use WS-Addressing GUDGIN et al. 2006, which provides a mechanism for asynchronous communication between Web
services. The default transport protocol is HTTP, but a client can also provide destinations that require other protocols.
Here we want to provide a mechanism that supports asynchronous communication between OGC Web services even if SOAP is not used. The schema elements provided in
this chapter can be taken as building blocks that can be used:
• to indicate which communication protocols a service supports,
• to indicate which message formats a service supports,
• to provide a common way for services to request communication endpoint
information from the client and