Title Page
Abstract
Contents
Chapter 1. Introduction 13
1.1. Background of Study 13
1.2. Research Objective 14
1.3. Thesis Outline 16
Chapter 2. Related Works 17
2.1. Transmission of Omnidirectional Videos 17
2.2. Transmission of Volumetric Videos 19
Chapter 3. System Overview 22
Chapter 4. Proposed Schemes 26
4.1. Geometric Distance based Caching 26
4.2. Exploring Speed aware Streaming 29
4.3. Modified Geometric Distance Caching Considering The Exploring Speed 32
Chapter 5. Experimental Results 36
5.1. Experiment Environment 36
5.2. Performance Evaluation of ESS 38
5.3. Performance Evaluation of GDC 42
5.4. System Demonstration on the 5G network 52
Chapter 6. Conclusion 56
Bibliography 57
Figure 1. Comparison of (a) spot-based VR and (b) Path-walking VR 14
Figure 2. Results from (a) Omnidirectional video (b) Point cloud (c) Light-field-based system 21
Figure 3. Overview of the Path-walking VR streaming environment 25
Figure 4. Snapshots of cache replacement according to viewer's moving route (a) first 6 views (b) second 6 views (c) third 6 views and (d) fourth 6 views... 28
Figure 5. Snapshots of cache replacement according to viewer's moving route (a) third 6 views and (b) fourth 6 views with the proposed GDC policy 28
Figure 6. The process of the selection a victim of replacement with GDC policy 29
Figure 7. Change of viewer's field of vision on a view image (a) four sub-views (b) When ESL=slow (c) When ESL=fast (d) When ESL=super-fast 31
Figure 8. The process of the decision of modified cache hit condition 33
Figure 9. Comparison of view update timeline (a) before applying partial hit condition (b) after applying partial hit condition 34
Figure 10. Walking scenarios in virtual space (a) simple_cycle (b) worst_cycle (c) maze_trace (d) museum_trace 37
Figure 11. Estimated Te2e comparison based on required network bandwidth[이미지참조] 41
Figure 12. Measured Te2e comparison[이미지참조] 42
Figure 13. Comparing the reduction of cache penalty for client as the cache hit rate for four walking scenarios (a) simple_cycle (b) worst_cycle (c) maze_trace (d) museum_trace 46
Figure 14. Comparing the reduction of cache penalty for server as the number of server requests for four walking scenarios (a) simple_cycle (b) worst_cycle (c) maze_trace (d) museum_trace 47
Figure 15. Immersive rate depending on four schemes, which are ESS+LRU, ESS+ARMA, Mahzari's and ESS+GDC, for four walking scenarios (a) simple_cycle (b) worst_cycle (c) maze_trace (d) museum_trace 53
Figure 16. Commercial 5G network experimental setup 54
Figure 17. E2E latency per segment for four walking scenarios (a) simple_cycle (b) worst_cycle (c) maze_trace (d) museum_trace in real 5G network 55