  Personal IoT data is a new economic asset that individuals can trade to
generate revenue on the emerging data marketplaces. Typically, marketplaces are
centralized systems that raise concerns of privacy, single point of failure,
little transparency and involve trusted intermediaries to be fair. Furthermore,
the battery-operated IoT devices limit the amount of IoT data to be traded in
real-time that affects buyer/seller satisfaction and hence, impacting the
sustainability and usability of such a marketplace. This work proposes to
utilize blockchain technology to realize a trusted and transparent
decentralized marketplace for contract compliance for trading IoT data streams
generated by battery-operated IoT devices in real-time. The contribution of
this paper is two-fold: (1) we propose an autonomous blockchain-based
marketplace equipped with essential functionalities such as agreement
framework, pricing model and rating mechanism to create an effective
marketplace framework without involving a mediator, (2) we propose a mechanism
for selection and allocation of buyers' demands on seller's devices under
quality and battery constraints. We present a proof-of-concept implementation
in Ethereum to demonstrate the feasibility of the framework. We investigated
the impact of buyer's demand on the battery drainage of the IoT devices under
different scenarios through extensive simulations. Our results show that this
approach is viable and benefits the seller and buyer for creating a sustainable
marketplace model for trading IoT data in real-time from battery-powered IoT
devices.
