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 mu W, of which 14 mu W is used to power the network interface circuits while the rest can be used to power signal acquisition circuitry. Fabricated in 0.18 mu m CMOS technology, the base station and the NNI occupy 2.95 mm(2) and 1.46 mm(2) area, respectively.