Renée: New Life for Old Phones

Discarded consumer electronics are a significant and growing source of hazardous waste. Repurposing smartphones has the potential to reduce the rate of disposal. However, reusing smartphones for general computational tasks is difficult due to the variety and domain specificity of the mobile software stack, and the relatively low computational power of these devices. We present the design and proof-of-concept implementation of Renée, a smartphone-based cluster built from used phones that provides function-as-a-service (FaaS) capabilities. Our experience indicates that reusing decommissioned smartphones for general computational tasks is not only feasible but also that a local cluster built from these devices has the potential to provide faster response times than commercial FaaS while reducing the yearly global warming potential of the reused devices.