SensorNet - Sensor Networks

Project: Mobile Networks

Mobile senor nodes enable a new set of possibilities for sensor networks. Since sensor nodes are leaving unattended after deployment several challenges exists. Due to the randomized deployment, parts of the area might be uncovered from the network. Mobile nodes are useful to find those uncovered areas and try to cover them. Mobile nodes are bigger in size and have not such limited energy resources as stationary sensor nodes. Therefore, mobile sensor nodes can be used as relay stations for data collection. Before every node send its data to the base station nearby mobile nodes can be used for collecting the data locally and physically transport the data to the base station.

Another important aspect of mobile sensor nodes is the idea of increasing the network lifetime. Nodes becoming unstable or may even fail when energy is depleting. Due to node failures, the probability increases that the remaining network will be unconnected. Preventing partitioning increases lifetime of the network. If the network consists only of static nodes, replacement of depleted nodes is impossible. Mobile nodes can move to those areas of the network were partitioning is already occurred or will occur in the near future.

In our project LEGO MINDSTORM robots are equipped with ESB sensor nodes, which controls the robot via an I2C bus. The bus is connecting the sensor node with the LEGO robot. Two sensor ports of the LEGO robot are converted via an electronic circuit to valid I2C signals. The ESB are supporting I2C bus directly and act as an I2C master.

LEGO robot with ESB node