A Study on Wireless Scheduling Architecture with Network Coding
네트워크 코딩 기반 무선 스케줄링 구조 연구
- 주제(키워드) Wireless Network , Wireless MAC , Wireless Scheduling , Network Coding
- 발행기관 고려대학교 대학원
- 지도교수 백상헌
- 발행년도 2010
- 학위수여년월 2010. 2
- 학위구분 석사
- 학과 일반대학원 전자전기공학과
- 세부전공 전자전기컴퓨터공학전공
- 원문페이지 43 p
- 실제URI http://www.dcollection.net/handler/korea/000000022340
- 본문언어 영어
- 제출원본 000045588996
초록/요약
Wireless networks are spreading rapidly with various types these days. But in their current form, wireless networks still have to undergo severe deterioration of link quality due to intrinsic defect of wireless medium such as fading and interference. But the broadcast nature, a unique characteristic of the wireless medium, gives the opportunity to multiple neighbor nodes to overhear one single transmission. One positive effect caused by broadcast nature of wireless medium is spatial diversity, so that various diversity schemes were proposed recently which aim to utilize spatial diversity of wireless network by inter-node cooperation or opportunistic routing so that improve network throughput highly. But, to utilize spatial diversity, those works inevitably sacrifice spatial reusability that it may drop utilization of wireless medium. On the other hand, emerging wireless network coding techniques are the solutions for capacity gain achievement with utilization of broadcast nature of wireless medium. However, those techniques are not feasible in highly lossy environments. This thesis present hybrid channel access scheme (HCAS), which intends to solve both problems by integrating opportunistic routing mechanism into inter- and intra-flow wireless network coding scheme in proper way. To utilize the inter-flow wireless network coding, multiple transmissions of flows should be allowed so that HCAS timely separate overall transmission stage as dissemination stage and collection stage. At the dissemination stage, each sender transmits their unicast packets to its neighbors, and then the neighbors of them retransmit what they have heard with wireless network coding at collection stage. The issues the HCAS mainly deal with and presents are as follow: i. Decision criteria of the flows to be encoded together with network coding at dissemination stage. ii. Efficient scheduling strategy of helpers for multiple receivers at the collection stage. HCAS chooses the flows which are generated in timely boundary within a broadcastable spatial range and draws greedy approach to retransmit them in with network coding. Through this approach, HCAS achieves a higher level of robustness and resource utilization.
more목차
ABSTRACT . I
TABLE OF CONTENTS III
LIST OF FIGURES . V
CHAPTER 1 INTRODUCTION 1
CHAPTER 2 BACKGROUNDS . 5
2.1 Diversity Schemes . 5
2.2 Network Coding . 8
2.3 Related Works and Motivation . 9
CHAPTER 3 HCAS: HYBRID CHANNEL ACCESS SCHEME . 13
3.1 Transmission Model . 14
3.1 Dissemination Stage . 15
3.2 Collection Stage 20
3.3 Dealing with Inter-Node Interference . 25
CHAPTER 4 PERFORMANCE EVALUATION 26
4.1 Simulation Model . 26
4.2. Simulation Process 27
4.3. Simulation Parameter . 27
4.4. Evaluation Results . 28
CHAPTER 5 CONCLUSION 32
REFERENCES . 34
ACKNOWLEDGEMENT. 35
