\begin{tikzpicture}[node distance=3em,nodes={rectangle,draw,minimum width=12em}]
% \node (0) [dotted] {Business layer};
% \node (1) [below=of 0] {Presentation layer};
- \node (1) [] {Presentation layer};
- \node (2) [below=of 1] {Application layer};
+ \node (1) [] {presentation};
+ \node (2) [below=of 1] {application};
% \node (3) [below=of 2] {Network layer};
- \node (3) [below=of 2] {Perception layer};
+ \node (3) [below=of 2] {perception};
\draw [<->] (1) -- (2);
\draw [<->] (2) -- (3);
-- ([yshift=-1em,xshift=1em]1.south east)
-- ([xshift=1em]1.north east)
-- ([xshift=3em]1.north east)
- -- node [draw=none,midway,sloped,below,yshift=-2pt] {Network layer} ([xshift=3em]3.south east)
+ -- node [draw=none,midway,sloped,below,yshift=-2pt] {network} ([xshift=3em]3.south east)
-- ([xshift=1em]3.south east)
-- ([yshift=1em,xshift=1em]3.north east)
-- ([xshift=1em,yshift=1em]3.north west)
-- ([yshift=2em,xshift=1em]3.north east)
-- ([yshift=-2em,xshift=1em]1.south east)
-- cycle;
- ;
+
+ \draw [densely dotted] (1.south) -- (2.north);
+ \draw [densely dotted] (2.south) -- (3.north);
\end{tikzpicture}
\end{document}