diff --git a/hw3/hw3.pdf b/hw3/hw3.pdf
index 77a56d3..ba9bbeb 100644
Binary files a/hw3/hw3.pdf and b/hw3/hw3.pdf differ
diff --git a/hw3/hw3.tex b/hw3/hw3.tex
index 88c53b8..1405179 100644
--- a/hw3/hw3.tex
+++ b/hw3/hw3.tex
@@ -41,5 +41,8 @@ The AP may also decide to boost its transmission power if possible, thus increas
 
 In alternative, if the station is in a ESS and another AP is present in the same subnet, the station may decide to hop from the first AP to the new AP if the latter has a better RSSI. If the DS uses switches, those should be informed of the change of BSS so as to keep their switching tables updated. 
 
+\section*{Exercise 5}
+Collision detection is \textit{avoided} in IEEE 802.11 since collisions, contrary to IEEE 802.3 Ethernet, are expensive to detect since the power of a received message is significantly lower than the power of transmission. In addition, if collision detection was used scenarios like the hidden terminal problem would not have been avoided.
+
 
 \end{document}