Date: 24 January 2013 Time: 11.00-12.15
Location: "Alkiviades C. Payatakes", Seminar Room, FORTH, Heraklion, Crete
Host: Maria Papadopouli
Energy efficiency is an important aspect in wireless networks and power management is a technique that can save energy. We mathematically analyze the discontinuous reception (DRX), a power saving mechanism in 3GPP LTE wireless networks. 3GPP LTE utilizes the DRX mechanism to reduce the power consumption of user equipments (UEs). DRX permits an idle UE to power othe radio receiver for a predefined sleep period and then wake up to receive the next paging message. The sleep/wake-up scheduling of each UE is determined by the following basic parameters: the inactivity timer, the short DRX cycle and the long DRX cycle. We model the power management scheme as a variant of a M/G/1 queue with modified multiple vacations. The modified vacation scheme consists of two periods, say a short DRX and a long DRX. Short DRX, has maximum number of N short cycles. Each cycle consists of a sleep and an on-duration. If N consecutive short cycles end without arrival, the server enters the long DRX which operates as the short DRX, but with longer sleep period. Steady state analysis is investigated and decomposition results are discussed. Energy and performance metrics are obtained and used to provide useful numerical results.
Dr Ioannis Dimitriou received the Diploma in Mathematics from the Mathematics Department of University of Ioannina in 2003 and the M.Sc. in Statistics and Operations Research and the PhD degree in Mathematics from the same institution in 2005 and 2009 respectively. During his postgraduate studies was financially supported by Greek State Scholarship Foundation (IKY). He was currently working as a Research Associate in the Dept. of Electrical and Electronic Engineering, Imperial College, London, UK and was involved in the EU project Fit4Green. On June 2011 was elected in a Lecturer position in the Department of Mathematics of the University of Patras. His research interests focus on queueing theory, stochastic processes, applied probability and stochastic modeling of computer and communication systems.