Techniques are described for switching from a data session to a voice session, then back to the data session. A "primary" data connection is established between a user's terminal and a communications network, which provides the user terminal with a tag identifying a voice network address (typically...http://www.google.es/patents/US5764736?utm_source=gb-gplus-sharePatente US5764736 - Method for switching between a data communication session and a voice communication session
Method for switching between a data communication session and a voice ...
