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Delay Optimal Opportunistic Access and Deadline Scheduling

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We consider two scheduling problems where delay performance is of considerable importance. The first problem arises from opportunistic medium access in a hierarchical cognitive radio network. In this context, a secondary user can observe the state of one of several channels at a time. The secondary user can only transmit if the primary user is not using the channel, and it must limit its interference (conditional probability of collision) to primary users below a certain threshold. We show that a simple myopic sensing and adaptive transmission policy achieves simultaneously throughput and delay optimality. Here delay is characterized by the queue length in the large deviation regime. The second problem deals with deadline scheduling with admission control. Such problems arise in the scheduling of deferrable load in smart grid applications. A particularly relevant example is the charging of electric vehicles in garages and parking lots where the each car arrives with certain charging needs, and the customer has some idea about how long the car can be left at the facility. The charger receives a reward if it finishes charging on time, and it is penalized if it fails to complete the job. We show that the optimal competitive ratio is 3-2\sqrt{2} and it can be achieved by a simple threshold admission and myopic scheduling policy.

Bio: Lang Tong is the Irwin and Joan Jacobs Professor in Engineering at Cornell University. He received the B.E. degree from Tsinghua University, Beijing, P.R. China, and PhD degree in EE from the University of Notre Dame, Notre Dame. He was a Postdoctoral Research Affiliate at the Information Systems Laboratory, Stanford University.Lang Tong's research is in the general area of statistical signal processing, communications, and complex networks. Using theories and tools from statistical inferences, information theory, and stochastic processes, he is interested in fundamental and practical issues that arise from wireless communications, security, and complex networks including power and energy networks and smart grids. Lang Tong received the 2004 Best Paper Award (with Min Dong) from the IEEE Signal Processing Society, the 2004 Leonard G. Abraham Prize Paper Award from the IEEE Communications Society (with Parvathinathan Venkitasubramaniam and Srihari Adireddy), and the 1993 Outstanding Young Author Award from the IEEE Circuits and Systems Society. He is a coauthor of seven student paper awards, including two IEEE Signal Processing Society Young Author Best Paper Awards (Qing Zhao in 2000 and Animashree Anandkumar in 2008) for papers published in the IEEE Transactions on Signal Processing. He was the recipient of the 1996 Young Investigator Award from the Office of Naval Research.

Status

  • Workflow Status:Published
  • Created By:Rachel Ponder
  • Created:10/21/2011
  • Modified By:Fletcher Moore
  • Modified:10/07/2016

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