S-Space College of Engineering/Engineering Practice School (공과대학/대학원) Dept. of Electrical and Computer Engineering (전기·정보공학부) Theses (Master's Degree_전기·정보공학부)
An Interference-Tolerant Routing Protocol in RPL-based Multi-hop Networks
- 공과대학 전기·정보공학부
- Issue Date
- 서울대학교 대학원
- 학위논문 (석사)-- 서울대학교 대학원 : 전기·정보공학부, 2016. 8. 박세웅.
- Low power and Lossy Networks (LLNs) are made up of many embedded devices. There is a wide scope of application areas for LLNs, including industrial monitoring, healthcare, smart grid AMIs, environmental monitoring, energy management and wireless sensor networks. Wireless sensors run on very constrained devices. So, there are some challenges like Link dynamics, overhead, and complexity.
RPL (Routing Protocol for low power and lossy networks) which is designed to overcome routing issues in LLNs is one of the most successful and widely used protocols.
Nowadays, more and more applications target indoor environment such as office, cafeteria and shopping mall. And several wireless technologies such as Wi-Fi, Bluetooth, Microwave shares the 2.4 GHz ISM band in those environments. Especially Wi-Fi Interference is one of the most critical factors in wireless sensor networks, and it is a new challenge in RPL.
Existing works proposed to improve performance under Wi-Fi interference. But, target of most schemes is link layer. We believe this is the first effort to solve the problem at routing layer.
RPL use ETX (Expected Transmission Count) to indicate link state. If it exceeds ETX-threshold, corresponding parent node will be evicted from parent candidate set. And ETX will be decreased when the node re-added to parent candidate set. But, because of such procedure, ETX value becomes unreliable under Wi-Fi interference.
This research proposes a scheme that could adjust ETX-threshold adaptively. And our results in multi-hop testbed shows that the performance of our scheme is superior to conventional RPL in terms of average end to end PRR, control over head and parent change count.