13698

12449

كارشناسي ارشد

معماري سيستم هاي كامپيوتري

اصفهان: دانشگاه صنعتي اصفهان، دانشكده برق و كامپيوتر

۱۳۹۷

دوازده، ۱۱۱ص.: مصور، جدول، نمودار

مجيد نبي

شاددرخ سماوي، نادر كريمي

1397/05/08

كتابنامه

برق و كامپيوتر

مهندسي برق و كامپيوتر

ID12449

Node Mobility Support for Time slotted Channel Hopping Wireless Sensor Networks Mahboobe Fakouri Zidesaraei m fakouri@ec iut ac ir Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Dr Majid Nabi nabi@cc iut ac ir Abstract The 6TiSCH protocol stack is introduced by IETF as a standard for communication of low power memory constrainedwireless devices in the Internet of Things IoT For its Medium Access Control MAC layer this protocol stack employsthe Time Slotted Channel Hopping TSCH mechanism which is as an operational modes of the IEEE 802 15 4 technologystandard This mechanism uses Time Division Multiple Access TDMA together with channel hopping which make thecommunications collision free and alleviate the impact of cross technology interference and multi path fading Thus themechanism is a suitable option for low power and reliable networking in IoT In the TDMA based protocols e g TSCH timeslot scheduling is done based on nodes neighborhood in such a way so that the nodes in each other s communicationrange pick different time slots for their packet transmissions Node mobility changes the neighborhood of the nodes in thenetwork leading to collisions The main challenge for node mobility support in TDMA based MMC layers is adapting thetimeslot schedules to avoid collisions Timeslot scheduling in a TSCH network can either be centralized or distributed Theformer scheduling method is not applicable for networks with node mobility due to its high overhead and complexity foradapting the schedules Thus the distributed scheduling mechanisms which only use local information are the main option However the scheduler should be fortified with proper adaptive mechanisms to efficiently support node mobility This thesisproposes solutions for supporting node mobility in networks running the 6TiSCH protocol stack The applications in whichthere is a static network as well as some mobile nodes e g health monitoring applications are considered The objectiveis to provide a communication mechanism in the TSCH layer for mobile nodes to reduce collisions due to mobility leadingto better Quality of Services such as end to end latency and data delivery ratio The main idea is to separate the static andmobile nodes and dedicate particular timeslots in each time period of TSCH for packet transmissions by the mobile nodes The proposed solutions are implemented on top of the Contiki operating system and their performance is evaluated by Coojasimulations of several network scenarios The achieved results shows that the solutions considerably reduces the end to endlatency and packet drop ratio for the scenarios with node mobility Key Words 1 Wireless Sensor Networks 2 6TiSCH 3 TSCH Protocol 4 Channel Hopping 5 Mobility

مجيد نبي

شاددرخ سماوي، نادر كريمي