A Scalable, 2.9 mW, 1 Mb/s e-Textiles Body Area Network Transceiver with Remotely-Powered Nodes and Bi-Directional Data Communication

Abstract

This paper presents transceivers and a wireless power delivery system for a Body-Area Network (BAN) that uses an e-textiles-based physical layer (PHY) capable of linking a diverse set of sensor nodes monitoring vital signs on the user's body. A central base station in the network controls power delivery and communication resource allotment for every node using a general-purpose on-chip Node Network Interface (NNI). The architecture of the network ensures fault-tolerance, reconfigurability and ease of use through a dual wireless-wireline topology. The nodes are powered at a peak end-to-end efficiency of 1.2% and can transmit measured data at a peak rate of 1 Mb/s. Modulation schemes for communication in both directions have been chosen and a Medium Access and Control (MAC) protocol has been designed and implemented on chip to reduce complexity at the power-constrained nodes, and move it to the base station. While transferring power to a single node at maximum efficiency, the base station consumes 2.9 mW power and the node recovers 34 µW, of which 14 µW is used to power the network interface circuits while the rest can be used to power signal acquisition circuitry. Fabricated in 0.18 µm CMOS technology, the base station and the NNI occupy 2.95 mm 2 and 1.46 mm 2 area, respectively.