Each issue of the IEEE Journal on Selected Areas in Communications (J-SAC) is devoted to a specific technical topic and thus provides to J-SAC readers a collection of up-to-date papers on that topic. These issues are valuable to the research community and become valuable references. The technical topics covered by J-SAC issues span the entire field of communications and networking. J-SAC publishes only papers that are submitted in response to a Call-for-Papers. These calls are published in J-SAC issues and other publications of the IEEE Communications Society as appropriate to the subject area of the call. Papers submitted for review for possible publication in a J-SAC issue must be submitted to one of the Guest Editors listed in the Call-for-Papers.