Adaptive MAC Protocols for Massive Devices in Cellular Network
Adaptive MAC Protocols for Massive Devices in Cellular Network
- 주제(키워드) massive devices , IoT , cellular network , random access , congestion control
- 발행기관 아주대학교
- 지도교수 김재현
- 발행년도 2017
- 학위수여년월 2017. 8
- 학위명 박사
- 학과 및 전공 일반대학원 전자공학과
- 실제URI http://www.dcollection.net/handler/ajou/000000026039
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
The main theme of this dissertation is the design of adaptive medium access protocol to alleviate the traffic overload and to provide resource efficiency for the massive number of devices. This dissertation focuses on the development of mechanisms to cope with the traffic overload due to the time-variant arrival of devices, and the mismatch between the estimated number of devices and the actual number of devices in cellular networks. This dissertation also focuses on efficient random access (RA) procedure for Internet of things (IoT) devices. The dynamic allocation of RACH resources (DARR) is one of solutions to alleviate the traffic overload from massive devices when the resource for RA can be increased. This dissertation discusses the challenge of a gap between the theoretical maximum throughput and the actual throughput in DARR. The gap occurs when the BS cannot change the number of preambles for a RACH until multiple numbers of RACHs are completed. In addition, a preamble partition (PP) approach is proposed that uses two groups of preambles to reduce this gap. The simulation results show that the proposed approach can achieve the throughput which is closer to theoretical maximum throughput than other approaches. The resources for the machine-to-machine (M2M) communication devices can be limited and shared with other type of devices. In this case, both the DARR and the access class barring (ACB) are required to provide resource efficiency and to alleviate the traffic overload. This dissertation discusses the gap between the theoretical maximum throughput and the actual throughput since the BS cannot change the number of preambles for a RACH until multiple number of RACHs are completed. Based on the discussion, a preamble partition and a stochastic gradient descent approach are proposed to reduce the gap when both of DARR and ACB are used for mobile network system. The simulation results show that the proposed protocol shows the throughput which is close to the throughput with ideal selection. The data transmission using a RA procedure for human-to-human (H2H) communications requires the overhead for signaling messages. The overhead for the signaling is very high compared with the size of data in small data transmission (SDT). Thus, the recent release of LTE-A standard includes two SDT procedures that reduce the number of exchanges. This dissertation evaluates the performance of conventional SDT procedures in the viewpoint of resource usage and resource throughput. In addition, this dissertation also proposes an SDT procedure to reduce the resource usage and to increase the resource efficiency. The numerical evaluation shows that the proposed approach decreases the resource usage and increases the resource efficiency.
more목차
1 Introduction 1
1.1 Background and motivation 1
1.2 Problem definition 4
1.3 Contribution 6
1.4 Overview 8
2 Background and Related Works 10
2.1 Data transmission procedure using RACH procedure in LTE-A 10
2.2 Access class barring and its related works 18
2.3 Dynamic allocation of RACH resource 20
3 Preamble Partition based Adaptive DARR Protocol 30
3.1 Introduction 30
3.2 System Model 31
3.3 Problem definition : Decrease of throughput in DARR due to resource allocation update interval 36
3.4 The Proposed Preamble Partition Protocol 43
3.5 Performance Evaluation 50
3.6 Summary 59
4 Preamble Partition based Adaptive DARR and ACB Protocol 60
4.1 Introduction 60
4.2 System Model 61
4.3 Problem Definition: Needs of adaptive MAC protocol considering si-periodicity 65
4.3.1 Background for the adaptive MAC protocol with DARR and ACB 66
4.3.2 Throughput degradation in DARR due to the resource allocation update interval 67
4.3.3 Throughput of ACB with ACB factor update interval 68
4.4 Proposed dynamic resource allocation and congestion control protocol 69
4.4.1 Background for device grouping 69
4.4.2 Background for the optimization with stochastic process 70
4.4.3 Preamble partition based adaptive resource allocation and congestion control protocol 73
4.5 Performance evaluation 77
4.6 Summary 89
5 Optimizing Random Access Procedure for the Data Transmission of MTC Devices 90
5.1 Introduction 90
5.2 System Model 92
5.3 Conventional procedures for the data transmission using RA 93
5.3.1 Control plane (CP) solution 93
5.3.2 User plane (UP) solution 97
5.3.3 Data in MSG1 99
5.3.4 Data in MSG3 100
5.4 Numerical evaluation for the conventional SDT procedures 102
5.4.1 CP solution 104
5.4.2 UP solution 108
5.4.3 Data in MSG1 110
5.4.4 Data in MSG3 111
5.5 Proposed short data transmission procedure for IoT devices 114
5.6 Numerical evaluation for the proposed SDT procedure 116
5.7 Performance Evaluation 118
5.8 Summary 124
6 Conclusion 125
References 128
