近年來IoT物聯網這個名詞已經悄悄的溜進了人類的生活中。無庸置疑的，有關物聯網相關的技術會在近幾年中蓬勃發展。儘管如此，物聯網的各個方面並非均衡發展。低成本、低功耗在物聯網的研究領域中已經成為趨勢。然而，物聯網的資料可靠性卻常常被忽略。為了補償資料可靠性的不足，本論文因此而誕生。
在這篇論文中，一套輕量化的通訊協定利用分層的方式被設計出來。除了具有能被實作在多種LPWAN技術上的靈巧性之外，這套設計也能確保資料的可靠性，並且具有延遲容忍的能力。在之後的實驗中，對於物聯網裝置來說，延遲容忍被證明是相當關鍵的能力之一。在本論文中，這套設計實作在NB-IoT的協定之上。資料聚合與延遲容忍這兩項特性預期能提升物聯網裝置的資料可靠度。本論文中提出的演算法，又稱資料篩選演算法，能確保在有限的儲存空間下，還能保有所有時間線下蒐集到的數據。最後為了評估效能，相關的實驗也已經被執行。nRF52832這塊由Nordic公司提供的微型控制器(MCU)，在本論文的實驗中會是重要的主角。其他硬體的細節也將會在稍後描述。
這篇論文提出的設計可以應用在智慧校園的概念中。智慧校園的概念也正是我們這所學校一直在提倡的。其他類似的概念，例如智慧城市或智慧建築，也是潛在的合適對象。這篇論文的目標是讓各種物聯網的應用更容易達成，讓我們的生活能夠充滿智慧。

Nowadays, IoT technologies have quietly sneaked into humans’ lives. Supposedly, the development of IoT related researches will be seen skyrocketing in recent years. Nevertheless, not all aspects of IoT technologies are studied equally. Low cost and long battery life have been trends in the research areas of IoT, but the data reliability is often overlooked. In order to compensate that, this thesis is therefore born.
In this thesis, a lightweight protocol stack is designed using layered approach. Versatile enough to be implemented on several LPWAN technologies, the design ensures the data reliability, and provides the capability of delay tolerance that is later proven to be crucial for many IoT devices. The design is further implemented on the top of NB-IoT protocols. Data aggregation and delay tolerance are expected to help IoT devices to improve data reliability. The proposed algorithm, Data Reselection Algorithm, retains all timelines of collected data in limited storage space. Finally, to validate the performance, related experiments are also done in this thesis. The MCU, nRF52832 from Nordic company, will be the main role in experiments. Other hardware details are also described later.
The design in this thesis may be applied to the concept of Smart Campus, which our university has been advocating. However, any smart concepts like Smart City or Smart Building may be suitable. This thesis aims at achieving IoT applications more effortless, making humans’ lives smarter.

ABSTRACT I
中文摘要 II
TABLE OF CONTENTS III
LIST OF FIGURES V
LIST OF TABLES VI
CHAPTER 1 INTRODUCTION 1
1.1 SMART CAMPUS 1
1.2 INTERNET OF THINGS 1
1.3 PLATFORM 2
1.4 SENSORS & ACTUATORS 3
1.5 LOW-POWER WIDE-AREA-NETWORK (LPWAN) 3
1.6 SMART BUILDING & SMART CITY 4
1.7 DATA RELIABILITY 4
1.8 DELAY TOLERANT 5
1.9 MOTIVATION 6
CHAPTER 2 RELATED WORK 7
2.1 IOT 7
2.1.1 LPWAN 10
2.1.2 LoRa & LoRaWAN 10
2.1.3 NB-IoT 13
2.1.4 MQTT 14
2.2 WSN 15
2.3 DELAY TOLERANT 16
2.4 IOT SENSORS & RELIABILITY 16
CHAPTER 3 SYSTEM DESIGN 17
3.1 LORAWAN AS UNDERLYING PROTOCOL 17
3.2 NB-IOT AS UNDERLYING PROTOCOL 18
3.3 PROPOSED PROTOCOL STACK DESIGN 18
3.4 OUTGOING DATA FLOW 19
3.4.1 Aggregated Outgoing Data Flow 21
3.5 INCOMING DATA FLOW 21
3.5.1 Acknowledgement Flow 23
CHAPTER 4 SYSTEM IMPLEMENTATION 26
4.1 HARDWARE OF IMPLEMENTATION 26
4.2 OVERVIEW OF THE PROPOSED DESIGN 27
4.3 UPLINK DATA MANAGER MODULE (UDMM) 29
4.3.1 Timestamp Implementation in UDMM 35
4.3.2 Storage Implementation in UDMM 36
4.4 TRANSFER RELIABILITY MODULE (TRM) 37
4.5 DATA TRANSFER MODULE (DTM) 43
4.5.1 Lower Part of DTM 46
4.6 DOWNLINK RECEPTION MODULE (DRM) 49
4.7 DATA RESELECTION ALGORITHM (DRA) 49
CHAPTER 5 EXPERIMENT SETTING & RESULTS 51
5.1 EXPERIMENT SETTINGS 51
5.2 EXPERIMENT RESULTS 53
CHAPTER 6 CONCLUSION 56
REFERENCES 57

"Vehicular ad hoc network," [Online]. Available: https://en.wikipedia.org/wiki/Vehicular_ad_hoc_network. [Accessed 22 7 2020].
"Internet of things - Wikipedia," [Online]. Available: https://en.wikipedia.org/wiki/Internet_of_things. [Accessed 20 07 2020].
C.-L. Zhong, Z. Zhu and R.-G. Huang, "Study on the IOT Architecture and Gateway Technology," 2015 14th International Symposium on Distributed Computing and Applications for Business Engineering and Science (DCABES), pp. 196-199, 8 2015.
S. Imtiaz, S. Ramin and V. Vlassov, "On the Case of Privacy in the IoT Ecosystem: A Survey," 2019 International Conference on Internet of Things (iThings) and IEEE Green Computing and Communications (GreenCom) and IEEE Cyber, Physical and Social Computing (CPSCom) and IEEE Smart Data (SmartData), pp. 1015-1024, 7 2019.
A. Hameed and A. Alomary, "Security Issues in IoT: A Survey," 2019 International Conference on Innovation and Intelligence for Informatics, Computing, and Technologies (3ICT), pp. 1-5, 9 2019.
S. Chaudhary, R. Johari, R. Bhatia, K. Gupta and A. Bhatnagar, "CRAIoT: Concept, Review and Application(s) of IoT," 2019 4th International Conference on Internet of Things: Smart Innovation and Usages (IoT-SIU), pp. 1-4, 4 2019.
D. D. Olatinwo, A. Abu-Mahfouz and G. Hancke, "A Survey on LPWAN Technologies in WBAN for Remote Health-Care Monitoring," Sensors, vol. 19, no. 23, p. 5268, 11 2019.
S. Aggarwal and A. Nasipuri, "Survey and Performance Study of Emerging LPWAN Technologies for IoT Applications," 2019 IEEE 16th International Conference on Smart Cities: Improving Quality of Life Using ICT & IoT and AI (HONET-ICT), pp. 69-73, 10 2019.
"LPWAN - Wikipedia," [Online]. Available: https://en.wikipedia.org/wiki/LPWAN. [Accessed 21 7 2020].
"LoRa - Wikipedia," [Online]. Available: https://en.wikipedia.org/wiki/LoRa. [Accessed 21 7 2020].
A. Augustin, J. Yi, T. Clausen and W. M. Townsley , "A Study of LoRa: Long Range & Low Power Networks for the Internet of Things," Sensors, vol. 16, p. 1466, 2016.
W. Ayoub, A. E. Samhat, F. Nouvel, M. Mroue and J.-C. Prévotet, "Internet of Mobile Things: Overview of LoRaWAN, DASH7, and NB-IoT in LPWANs Standards and Supported Mobility," IEEE Communications Surveys & Tutorials, vol. 21, pp. 1561-1581, 2019.
P. Andres-Maldonado, P. Ameigeiras, J. Prados-Garzon, J. Navarro-Ortiz and J. M. Lopez-Soler, "Narrowband IoT Data Transmission Procedures for Massive Machine-Type Communications," IEEE Network, vol. 31, no. 6, pp. 8-15, 11 2017.
"Narrowband IoT - Wikipedia," [Online]. Available: https://en.wikipedia.org/wiki/Narrowband_IoT. [Accessed 21 7 2020].
L. Gregora, L. Vojtech and M. Neruda, "Indoor signal propagation of LoRa technology," 2016 17th International Conference on Mechatronics - Mechatronika (ME), pp. 1-4, 14 2016.
"Internet protocol suite - Wikipedia," [Online]. Available: https://en.wikipedia.org/wiki/Internet_protocol_suite. [Accessed 22 7 2020].
"MQTT - Wikipedia," [Online]. Available: https://en.wikipedia.org/wiki/MQTT. [Accessed 21 7 2020].
M. B. Yassein, M. Q. Shatnawi, S. Aljwarneh and R. Al-Hatmi, "Internet of Things: Survey and open issues of MQTT protocol," 2017 International Conference on Engineering & MIS (ICEMIS), pp. 1-6, 5 2017.
"Wireless sensor network - Wikipedia," [Online]. Available: https://en.wikipedia.org/wiki/Wireless_sensor_network. [Accessed 21 7 2020].
L. Hu, Y. Li, Q. Chen, J.-Y. Liu and K.-P. Long, "A New Energy-Aware Routing Protocol for Wireless Sensor Networks," 2007 International Conference on Wireless Communications, Networking and Mobile Computing, pp. 2444-2447, 9 2007.
H. Wang, G. Yang, J. Xu, Z. Chen, L. Chen and Z. Yang, "A noval data collection approach for Wirelsee Sensor Networks," 2011 International Conference on Electrical and Control Engineering, pp. 4287-4290, 9 2011.
F. Gao, H. Wen, L. Zhao and Y. Chen, "Design and optimization of a cross-layer routing protocol for multi-hop wireless sensor networks," PROCEEDINGS OF 2013 International Conference on Sensor Network Security Technology and Privacy Communication System, pp. 5-8, 5 2013.
N. Nake and P. Chatur, "A review on hierarchical routing methods in sink based wireless sensor networks," 2016 2nd International Conference on Advances in Electrical, Electronics, Information, Communication and Bio-Informatics (AEEICB), pp. 259-262, 2 2016.
H. B. Fradj, R. Anane, M. Bouallegue and R. Bouallegue, "A range-based opportunistic routing protocol for Wireless Sensor networks," 2017 13th International Wireless Communications and Mobile Computing Conference (IWCMC), pp. 770-774, 7 2017.
M. Sana and L. Noureddine, "Multi-hop energy-efficient routing protocol based on Minimum Spanning Tree for anisotropic Wireless Sensor Networks," 2019 International Conference on Advanced Systems and Emergent Technologies (IC_ASET), pp. 209-214, 3 2019.
M. Sonthalia, A. Jha, U. Gupta and J. Thyagarajan, "A Real Time Implementation of Hierarchical Routing Protocol for IoT based Wireless Sensor Network," 2019 International Conference on Wireless Communications Signal Processing and Networking (WiSPNET), pp. 512-516, 3 2019.
A. Omidvar and K. Mohammadi, "Intelligent routing in delay tolerant networks," 2014 22nd Iranian Conference on Electrical Engineering (ICEE), pp. 846-849, 5 2014.
A. Socievole and S. Marano, "Evaluating the impact of energy consumption on routing performance in delay tolerant networks," 2012 8th International Wireless Communications and Mobile Computing Conference (IWCMC), pp. 481-486, 8 2012.
A. Luntovskyy and L. Globa, "Performance, Reliability and Scalability for IoT," 2019 International Conference on Information and Digital Technologies (IDT), pp. 316-321, 7 2019.
M. Ahmad, "Reliability Models for the Internet of Things: A Paradigm Shift," 2014 IEEE International Symposium on Software Reliability Engineering Workshops, pp. 52-59, 11 2014.
C. Kamyod, "Reliability Analysis of The Smart Farm System: A Case Study of Small and Medium-Sized Farm-Thailand," 2019 22nd International Symposium on Wireless Personal Multimedia Communications (WPMC), pp. 1-5, 11 2019.
A. Mavrogiorgou, A. Kiourtis, C. Symvoulidis and D. Kyriazis, "Capturing the Reliability of Unknown Devices in the IoT World," 2018 Fifth International Conference on Internet of Things: Systems, Management and Security, pp. 62-69, 10 2018.
G. Jia , Y. Zhu, Y. Li , Z. Zhu and L. Zhou, "Analysis of the Effect of the Reliability of the NB-Iot Network on the Intelligent System," IEEE Access, vol. 7, pp. 112809-112820, 7 2019.
"User Datagram Protocol - Wikipedia," [Online]. Available: https://en.wikipedia.org/wiki/User_Datagram_Protocol. [Accessed 20 07 2020].
S.-Y. Wang and T.-Y. Chen, "Increasing LoRaWAN Application-Layer Message Delivery Success Rates," 2018 IEEE Symposium on Computers and Communications (ISCC), pp. 148-153, 6 2018.
"Microcontroller - Wikipedia," [Online]. Available: https://en.wikipedia.org/wiki/Microcontroller. [Accessed 20 07 2020].
"LIS3DH - 3-axis MEMS accelerometer, ultra-low-power, ±2g/±4g/±8g/±16g full scale, high-speed I2C/SPI digital output, embedded FIFO, high-performance acceleration sensor, LLGA 16 3x3x1.0 package," [Online]. Available: https://www.st.com/en/mems-and-sensors/lis3dh.html. [Accessed 19 7 2020].
"I²C - Wikipedia," [Online]. Available: https://en.wikipedia.org/wiki/I%C2%B2C. [Accessed 20 07 2020].
"Humidity Sensor BME280 | Bosch Sensortec," [Online]. Available: https://www.bosch-sensortec.com/products/environmental-sensors/humidity-sensors-bme280/. [Accessed 19 7 2020].
"Serial Peripheral Interface - Wikipedia," [Online]. Available: https://en.wikipedia.org/wiki/Serial_Peripheral_Interface. [Accessed 20 07 2020].
"Quectel GPS L70-R," [Online]. Available: https://www.quectel.com/product/l70r.htm.
"Quectel GPS L70-RL," [Online]. Available: https://www.quectel.com/product/l70rl.htm. [Accessed 19 7 2020].
"Universal asynchronous receiver-transmitter - Wikipedia," [Online]. Available: https://en.wikipedia.org/wiki/Universal_asynchronous_receiver-transmitter. [Accessed 20 07 2020].
"Bluetooth - Wikipedia," [Online]. Available: https://en.wikipedia.org/wiki/Bluetooth. [Accessed 20 07 2020].
"nRF52832 - Versatile Bluetooth 5.2 SoC - nordicsemi.com," [Online]. Available: https://www.nordicsemi.com/Products/Low-power-short-range-wireless/nRF52832. [Accessed 19 7 2020].
"Reduced instruction set computer - Wikipedia," [Online]. Available: https://en.wikipedia.org/wiki/Reduced_instruction_set_computer. [Accessed 19 7 2020].
"Bluetooth_5.2_Feature_Overview.pdf," [Online]. Available: https://www.bluetooth.com/wp-content/uploads/2020/01/Bluetooth_5.2_Feature_Overview.pdf. [Accessed 19 7 2020].