TIME SYNCHRONIZATION/STAMPING METHOD WITH VISIBLE LIGHT COMMUNICATION AND ENERGY HARVESTING METHOD FOR WIRELESS SENSOR NETWORK INSIDE ARIANE 5 VEHICLE EQUIPMENT BAY

摘要

In this work we design and implement efficientrntime synchronization/stamping method for Wireless SensorrnNetwork inside the Vehicle Equipment Bay (VEB) of thernARIANE 5. The sensor nodes in the network do not require realrntime clock (RTC) hardware to store and stamp eachrnmeasurement data performed by the sensors. There will be onlyrnthe measurement sequence information, previous time (clock)rninformation, measurement data and its related data protocolrninformation sent back to the Access Point (AP). This lead to lessrndata transmission, less energy and less time required by thernsensor nodes to operate and also leads to longer battery life time.rnThe Visible Light Communication (VLC) is used, to providernenergy, to synchronize time and to deliver the commands to thernsensor nodes in the network. By employing star networkrntopology, a part of solar cell as receiver, the conventional receiverrn(RF/Infrared) is neglected to reduce amount of hardware andrnenergy consumption. The infrared transmitter on the sensor nodernis deployed to minimize the electromagnetic interference in thernlauncher and does not require a complicated circuit inrncomparison to a RF transmitter.