Analysis of Handover Performance in LEO based Non-terrestrial Network
- 주제(키워드) LEO , Handover
- 주제(DDC) 004.6
- 발행기관 아주대학교
- 지도교수 김재현
- 발행년도 2022
- 학위수여년월 2022. 2
- 학위명 석사
- 학과 및 전공 일반대학원 AI융합네트워크학과
- 실제URI http://www.dcollection.net/handler/ajou/000000031577
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Recently, as non-terrestrial networks (NTN) are recognized as new access networks, the communication paradigm is changing. The 3rd generation partnership project (3GPP) started standardizing new radio (NR)-based NTN in release 15. NTN’s wide coverage expand the network system of next-generation mobile communication. In particular, low earth orbit (LEO) satellites have a good deal of potential commercially, with costs drastically reduced due to reusable rockets. However, LEO-based NTN has a mobility issue different from that of terrestrial network (TN). The high mobility of the LEO shortens the time the terminal stays for each cell. As a result, frequent handover occurs, and the performance of handover becomes a more important issue. In addition, LEO, which operates at a high altitude, makes the RSS variation of a cell small. It is difficult to expect high performance when applying TN’s RSS-based handover method. 3GPP recognizes this issues and discusses a handover method using location information. Several method of measurement report triggering have been proposed for the handover method using location information, but the specific method is unclear. This is because there is a lack of performance analysis data for each method. In this dissertation, the LEO-based NTN environment is implemented on a cellular basis and the performance of handover method using location information is analyzed. Similar to the A3 event, the location-based event triggers the measurement report when a center of neighbor cell becomes closer than that of serving cell. The handover process is divided into states to compare the performance of RSRP-based events and location-based events. The location-based event has higher accuracy than signal strength, which has randomness by fading. In an environment of the NTN with little change in signal intensity, the location-based event is advantageous because the influence of fading acts larger than that of the TN. As a result of simulation, location-based event show higher performance in terms of RLF per second, handover failure rate, handover delay, interruption time and radio resource control re-establishment success rate.
more목차
1 Introduction 1
1.1 Background and motivation 1
1.2 Contributions 3
2 Related work 4
2.1 Handover of Terrestrial Network in 3GPP 4
2.1.1 Radio link failure 4
2.1.2 Measurement report 6
2.1.3 Handover decision 8
2.1.4 Handover process 8
2.2 LEO-based NTN handover issues 11
2.2.1 The amount of change in received signal strength 11
2.2.2 Frequent handover 12
2.2.3 Ephemeris information 12
2.3 study cases 14
3 Methodology 16
3.1 Simulation tool 16
3.2 System model 17
3.3 Scenario assumption 22
3.4 Location-based handover 25
4 Performance Evaluation 27
4.1 Key performance indicators 27
4.2 Simulation results 31
5 Conclusion 43
References 45
