Processor-Sharing Internet of Things Architecture for Large-scale Deployment

Large-scale IoT sensor deployment calls for inexpensive, low-power sensor nodes that still perform long-range, large-scale networking at the system level. However, current sensor nodes are constructed according to the 'one-size-fits-all' embedded design, where the processor and RF transceiver are indispensable but underutilized in low-duty cycles, resulting in overwhelmingly significant unit price and run-time power. In this paper, we propose a novel processor-sharing IoT architecture that converts the vast majority of sensor nodes from embedded computers to low-end RF peripherals. The conventional full-fledged sensor nodes are smashed into the air, and the scattered chips are scaled well with negligible overheads through a virtual I²C bus called RFBus. Specifically, the RFBus interface is designed to be backward compatible with the I²C bus interface, and thus, the RFBus network inherits versatile link layer services transparently from the well-established I²C link layer protocol. We design the RFBus with a joint consideration of system-level performance and deployment costs and evaluate the prototypes in indoor and outdoor scenarios. The result indicates that the proposed architecture achieves 6.09 x (indoor) and 6.69 x (outdoor) energy saving and reduces the unit price of sensor nodes by 23.5% (indoor) and 33.5% (outdoor).