X-Git-Url: https://git.rohieb.name/skm-ma-ws1314.git/blobdiff_plain/9c0186068ed8d750cbae9dae7740f312a7663fe8..refs/tags/final:/sec-discussion.tex diff --git a/sec-discussion.tex b/sec-discussion.tex index 0f05d0c..2b26283 100644 --- a/sec-discussion.tex +++ b/sec-discussion.tex @@ -24,15 +24,6 @@ interested in specific values then only needs to communicate with a single node in the network. \paragraph{Sensor Data (XEP-0323)~\cite{xep0323}} -%\begin{figure} - %\caption{Example stream between a sensor node and a client} - %\label{fig:streamexample} - %\begin{verbatim} -%Client Device -% - - %\end{verbatim} -%\end{figure} This XEP specifies a way of reading out values from a sensor node. It allows to specify multiple data sources (e.~g. temperature, humidity) as well as multiple types of data (e.~g., momentary values, historical @@ -43,6 +34,14 @@ accepts the request by returning a corresponding IQ stanza. If it has accepted the request, it reads out the requested data and returns it in a subsequent message stanza to the client. +An example of this protocol can be seen in Figure~\ref{fig:examplexmpp}: after +both clients have opened their streams, the client requests the momentary values +for power and energy from the node named \emph{Device04}. The device first +acknowledges this request, and, after retrieving the values, sends them back +to the client. + +\input{fig-example-xmpp-stream.tex} + \paragraph{Control (XEP-0325)~\cite{xep0325}} In this document, a way of controlling sensor nodes is specified, which allows a client to get and set control values on the node over message or IQ stanzas. As an example, in this @@ -75,9 +74,6 @@ it is to be noted that this requires further implementation of compression algorithms as well as additional CPU and memory resources and thus might decrease message throughput and increase power consumption on embedded systems. - -\todo{example XML stream with sensor data} - \subsection{Related Approaches} ``Chatty Things'' is not the only approach to implement communication in