NeTS: Small: Meeting Hard Deadlines of Real Time Traffic: From Wireless Scheduling to Smart Charging

NeTS: Small: Meeting Hard Deadlines of Real Time Traffic: From Wireless Scheduling to Smart Charging NeTS: Small: Meeting Hard Deadlines of Real-Time Traffic: From Wireless Scheduling to Smart Charging Recent years have witnessed a tremendous growth in multimedia applications in wireless systems [3]. Real-time applications such as VoIP and real-time video will continue to take communications to the next level beyond texts and images. Typically, real-time traffic has more stringent quality of service (QoS) requirements, in terms of minimum bandwidth and maximum packet delay. Furthermore, realtime traffic is often prioritized at the packet level, e.g., in video streaming, video packets encoded by MPEG, have different priorities according to the distortion reduction of each packet in reconstructing the original media [4]. All of these features make the real-time scheduling problem challenging, not to mention the unreliable nature of wireless channels. Along a different avenue, the growing concerns over energy security and environmental issues are propelling the electrification of transportation and more specifically the development of plugin electric vehicle (EV) technology. A large-scale implementation of EVs is being planed in the near future (the US administration has planned to put 1 million EVs on the road by 2015). One major obstacle towards realizing large-scale implementation is the efficient charging of EVs, which can be cast as a deadline scheduling problem. Specifically, consider the problem of scheduling the charging of plug-in electric vehicles (EV) at a facility, where upon arrival, EVs submit charging request and are then queued until their respective deadlines, during which time an operator can schedule any pending requests in the system. In general, there is no guarantee that a submitted charging request will be completed by its deadline. It has been widely recognized that the high penetration level of PEVs will cause considerable impact on the existing power system. The analysis of [4454] has predicted that a significant amount of PEV charging will take place during the peak load period, causing branch congestions and voltage problems. Studies in [55, 56] have shown that the existing distribution system infrastructure may only support a low PEV penetration level. Without proper coordination, the coincidence between peaks of EV-load and non-EV load would require investment in generation, transmission, and distribution, in order to maintain the reliability of the power system.