system architecture which Klauck and
Kirsche~\cite{Klauck:2012:BCC:2352852.2352881} use to build Chatty Things.
-\todo
\pages{3}
\subsection{Service Provisioning Sublayer}
In scenarios without an XMPP server, the XEP-0174 module is activated and
devices talk directly with the user or with other devices. This method has the
drawback that Multi-User Chats cannot be used for topic filtering, since no
-method is specified to do XEP-0045 and XEP-0174 at the same time. \todo[temporary subscription presence here?]
-In this case,
+method is specified to do XEP-0045 and XEP-0174 at the same time. In this case,
a user must have an XEP-0174-compliant chat client, but it also gives her the
opportunity to interact with things spontaneously on an ad-hoc basis (e.~g. when
entering a room) without need for any additional gateway on the application