| Abstract: | Due to advances in low power sensors, energy harvesting, and disruption tolerant networking, we can now build mobile systems that operate perpetually, sensing and streaming data directly to scientists. However, factors such as energy harvesting variability and unpredictable network connectivity, make building robust and perpetual systems difficult. In this paper, we present a system, Tula, that balances sensing with data delivery, to allow perpetual and robust operation across highly dynamic and mobile networks. This balance is important, especially in an unpredictable environment; sensing more data than can be delivered by the network is not useful, while gathering less underutilizes the system’s potential. Tula is decentralized, fair and automatically
adapts across different mobility patterns. We evaluate Tula in the context of two mobile testbeds, TurtleNet and UMass DieselNet. TurtleNet is a mobile sensor network that we deployed to study Gopher tortoises. DieselNet is a mobile network testbed consisting of 40 vehicles.
Our evaluations show that Tula senses and delivers data within 80% of an optimal, oracular system that perfectly replicates data and has foreknowledge of future energy harvesting. We also demonstrate that Tula can be implemented on a small microcontroller with modest code,
memory, and processing requirements. |
