LTE-Advanced DRX Mechanism for Power Saving

PREFACE ix

INTRODUCTION xi

CHAPTER 1. BASIC THEORY 1

1.1. LTE overview 2

1.2. Scheduling in LTE 5

1.2.1. Quality of Service parameters 6

1.2.2. Channel quality indicator 8

1.2.3. Buffer state and resource allocation history 10

1.3. LTE Traffic measurements 11

1.3.1. Testing environment 12

1.3.2. VoIP preliminary capacity 13

1.3.3. Video conversation preliminary capacity 14

1.3.4. Post video and live video preliminary capacity 15

1.3.5. Summary on the LTE Traffic measurements 18

1.4. User equipment power saving in LTE 18

1.4.1. DRX cycle 18

1.5. Models for LTE Power Saving 24

1.5.1. 3GPP power consumption model 25

1.5.2. Characteristics of NokiaTM power consumption model 26

1.6. Conclusion 29

1.7. Bibliography 30

CHAPTER 2. ANALYTICAL SEMI-MARKOV POWER-SAVING MODELS  33

2.1. Introduction of bursty packet data traffic 33

2.2. Designing a simple Two-state DRX model using semi-Markov 36

2.2.1. State 1 to state 1 and state 1 to state 2 38

2.2.2. Transition probability matrix 39

2.2.3. How we obtain equation [2.4] 39

2.2.4. Holding states 40

2.2.5. State H1 40

2.2.6. Sleep states H2 42

2.2.7. DRX cycles in basic 3GPP LTE 43

2.2.8. Wake-up delay 43

2.2.9. Power-saving factor (PS) 44

2.2.10. Numerical results 44

2.3. Three-state fixed model 47

2.3.1. State 1 to state 1 and state 1 to state 2 49

2.3.2. State 2 to state 1 and state 2 to state 3 49

2.3.3. Transition probability matrix 50

2.3.4. State H1 51

2.3.5. Sleep states H2 and H3 51

2.3.6. Power-saving factor (PS) 52

2.3.7. Numerical results 54

2.3.8. Summary of the Three-state model 59

2.4. Four-state fixed model 60

2.4.1. State 1 to state 1, state 1 to state 2 and state 1 to state 3 61

2.4.2. State 2 to state 1, state 2 to state 2 and state 2 to state 3 61

2.4.3. State 3 to state 1, state 3 to state 2 and state 3 to state 4 62

2.4.4. State 4 to state 1 and state 4 to state 2 63

2.4.5. Transition probability matrix 63

2.4.6. Sleep states H3 and H4 65

2.4.7. Power-saving factor (PS) 66

2.4.8. Numerical results 68

2.5. Conclusion 69

2.6. Bibliography 69

CHAPTER 3. OTHER APPROACHES FOR LTE POWER SAVING  71

3.1. Scheduling schemes 71

3.2. DRX power-saving method 74

3.3. Analytical work 78

3.4. Analytical Adjustable-DRX Three-state model 79

3.4.1. Adjustable DRX timer state for light sleep 79

3.4.2. State 2 to state 1 and state 2 to state 3 80

3.4.3. Transition probability matrix 81

3.4.4. Adjustable DRX cycles in 3GPP LTE 82

3.4.5. Sleep states H2 and H3 83

3.4.6. Power-saving factor (PS) 84

3.4.7. Numerical results 86

3.5. Conclusion 92

3.6. Bibliography 92

ACRONYMS AND NOTATIONS 95

INDEX 101