Second Quarter 2013, IEEE Communications Surveys & Tutorials

This is the second issue of the IEEE Communications Surveys and Tutorials (ComST) in 2013. This issue includes twenty articles covering different aspects of communication networks. In particular, these articles cover issues related to medium access control (MAC) and routing protocols in wireless ad hoc and sensor networks, routing in delay-tolerant networks, scheduling and multicasting in LTE/LTE-A networks, wireless multimedia communications, network security, industrial control networks, communications technologies for space networks, and optical networks.