We warmly welcome you to the 2013 IEEE Online Conference on Green Communications, the third edition conducted entirely online and dedicated to addressing the challenges in energy-efficient communications and communications for green technologies. Continuing with the experience provided last two edition, IEEE OnlineGreenComm'13 will be held entirely online, to emphasize the need for reducing global greenhouse gas emissions, avoiding the most polluting aspects of conferences, the use of mass transport systems for traveling. The conference embraces the latest online conferencing technology that will allow attendees to match the experience and networking aspects of face to face meetings. Common to all IEEE conferences, IEEE OnlineGreenComm will feature a full-fledged paper submission, review, and publication process that adheres to the high standards defined by IEEE’s. This process will be supplemented with additional content from online presentations that will be made available through IEEE ComSoc Webcasts. IEEE OnlineGreenComm covers a wide spectrum of research subjects, including green methodologies and architectures for communication technologies, communication technologies as enablers for green solutions, energy efficient in Smart Grid comunications and energy management. For more information on IEEE OnlineGreenComm’s topics and how to submit your paper, please refer to calls & submit.