Spectrum model documetation placeholder

doc/models/Makefile

@@ -65,6 +65,7 @@ SOURCES = \
 	$(SRC)/wimax/doc/wimax.rst \
 	$(SRC)/uan/doc/uan.rst \
 	$(SRC)/topology-read/doc/topology.rst \
+	$(SRC)/spectrum/doc/spectrum.rst \
 	$(SRC)/stats/doc/statistics.rst \
 	$(SRC)/netanim/doc/animation.rst \
 	$(SRC)/flow-monitor/doc/flow-monitor.rst \

src/spectrum/doc/spectrum.rst

@@ -0,0 +1,14 @@
+.. include:: replace.txt
+
+Spectrum model
+--------------
+
+*Placeholder chapter*
+
+|ns3| Spectrum model support advanced spectrum modeling functionalities for the simulation of wireless networks.
+
+The model is described in [Baldo2009]_. 
+
+.. [Baldo2009] N. Baldo and M. Miozzo, "Spectrum-aware Channel and PHY layer modeling for ns3", 
+   Proceedings of ICST NSTools 2009, Pisa, Italy. 
+