LTE-Advanced DRX Mechanism for Power Saving

Resource allocation and power optimization is a new challenge inmultimedia services in cellular communication systems. Toprovide a better end-user experience, the fourth generation (4G)standard Long Term Evolution/Long Term Evolution-Advanced(LTE/LTE-Advanced) has been developed for high-bandwidth mobileaccess to accommodate today's data-heavy applications.LTE/LTE-Advanced has adopted discontinuous reception (DRX) toextend the user equipment's battery lifetime, thereby furthersupporting various services and large amounts of datatransmissions.By introducing the basics of mathematical analysis and performanceevaluation of power-saving mechanisms in 3rd generation partnershipproject (3GPP) LTE and LTE-Advanced networks, the authors of thisbook aim to describe novel algorithms which could have betterperformance capabilities than previous methods.Chapter 1 gives the basic theory description of the 3GPP LTEnetwork and 3GPP DRX power saving mechanism, empirical measurementsof LTE network traffic and an overview of the basic LTE DRX modelin the field of power saving techniques. Chapter 2 provides stepsfor deriving a 2-state analytical model up to a 4-state DRX model.The third and final chapter summarizes alternative methods for theimplementation of LTE DRX.Contents1. Basic Theory.2. Analytical Semi-Markov Power-Saving Models.3. Other Approaches for LTE Power Saving.About the AuthorsScott A. Fowler is Associate Professor at LinköpingUniversity, Sweden, working with the Mobile Telecommunication (MT)group. He has served on several IEEE conferences/workshops as TPCto Chair, including Special Interest Groups coordinator for IEEECommunications Software (CommSoft) Technical Committee since 2012.His research interests include Quality of Service (QoS) supportover heterogeneous networks, computer networks (wired, wireless),energy management, mobile computing, pervasive/ubiquitous,performance evaluation of networks and security.Abdelhamid Mellouk is Full Professor at the University of Paris-EstCréteil VdM (UPEC, ex. Paris 12), Networks &Telecommunications (N&T) Department (IUT C/V) and LiSSiLaboratory in France. He is a founder of the Network ControlResearch activity with extensive international academic andindustrial collaborations. His general area of research is inadaptive real-time control for high-speed new generation dynamicwired/wireless networking in order to maintain acceptable Qualityof Service/Experience for added-value services.Naomi Yamada is a research associate at Linköping University,Sweden.

PREFACE ixINTRODUCTION xiCHAPTER 1. BASIC THEORY 11.1. LTE overview 21.2. Scheduling in LTE 51.2.1. Quality of Service parameters 61.2.2. Channel quality indicator 81.2.3. Buffer state and resource allocation history 101.3. LTE Traffic measurements 111.3.1. Testing environment 121.3.2. VoIP preliminary capacity 131.3.3. Video conversation preliminary capacity 141.3.4. Post video and live video preliminarycapacity 151.3.5. Summary on the LTE Traffic measurements 181.4. User equipment power saving in LTE 181.4.1. DRX cycle 181.5. Models for LTE Power Saving 241.5.1. 3GPP power consumption model 251.5.2. Characteristics of NokiaTM power consumptionmodel 261.6. Conclusion 291.7. Bibliography 30CHAPTER 2. ANALYTICAL SEMI-MARKOV POWER-SAVING MODELS332.1. Introduction of bursty packet data traffic 332.2. Designing a simple Two-state DRX model usingsemi-Markov 362.2.1. State 1 to state 1 and state 1 to state 2 382.2.2. Transition probability matrix 392.2.3. How we obtain equation [2.4] 392.2.4. Holding states 402.2.5. State H1 402.2.6. Sleep states H2 422.2.7. DRX cycles in basic 3GPP LTE 432.2.8. Wake-up delay 432.2.9. Power-saving factor (PS) 442.2.10. Numerical results 442.3. Three-state fixed model 472.3.1. State 1 to state 1 and state 1 to state 2 492.3.2. State 2 to state 1 and state 2 to state 3 492.3.3. Transition probability matrix 502.3.4. State H1 512.3.5. Sleep states H2 and H3 512.3.6. Power-saving factor (PS) 522.3.7. Numerical results 542.3.8. Summary of the Three-state model 592.4. Four-state fixed model 602.4.1. State 1 to state 1, state 1 to state 2 and state 1 tostate 3 612.4.2. State 2 to state 1, state 2 to state 2 and state 2 tostate 3 612.4.3. State 3 to state 1, state 3 to state 2 and state 3 tostate 4 622.4.4. State 4 to state 1 and state 4 to state 2 632.4.5. Transition probability matrix 632.4.6. Sleep states H3 and H4 652.4.7. Power-saving factor (PS) 662.4.8. Numerical results 682.5. Conclusion 692.6. Bibliography 69CHAPTER 3. OTHER APPROACHES FOR LTE POWER SAVING713.1. Scheduling schemes 713.2. DRX power-saving method 743.3. Analytical work 783.4. Analytical Adjustable-DRX Three-state model 793.4.1. Adjustable DRX timer state for light sleep 793.4.2. State 2 to state 1 and state 2 to state 3 803.4.3. Transition probability matrix 813.4.4. Adjustable DRX cycles in 3GPP LTE 823.4.5. Sleep states H2 and H3 833.4.6. Power-saving factor (PS) 843.4.7. Numerical results 863.5. Conclusion 923.6. Bibliography 92ACRONYMS AND NOTATIONS 95INDEX 101