Wireless distributed microsensor systems will enable the reliable monitoring and control of a variety of applications that range from medical and home security to machine diagnosis, chemical/biological detection and other military applications. The sensors have to be designed in a highly integrated fashion, optimizing across all levels of system abstraction, with the goal of minimizing energy dissipation. This paper addresses some of the key design considerations for future microsensor systems including the network protocols required for collaborative sensing and information distribution, system partitioning considering computation and communication costs, low energy electronics, power system design and energy harvesting techniques. 1. Introduction Over the last few years, the design of micropower wireless sensor systems has gained increasing importance for a variety of civil and military applications. The Low Power Wireless Integrated Microsensors (LWIM) project has made major advan...

The power dissipation associated with driving data busses can be significant, especially considering the increasing component of inter-wire capacitance. Previous work on bus encoding has focused on minimizing transitions to reduced power dissipation. In this paper, it is shown that transition reduction is not necessarily the best approach for reducing power when the effects of inter-wire capacitance are considered. An electrical model for data busses designed with submicron technologies is presented along with a family of coding techniques that can reduce the average power consumption of the bus by 40%. 2.

This paper describes a new circuit technique for designing noise-tolerant dynamic logic. It is shown that voltage scaling aggravates the crosstalk noise problem and reduces circuit noise immunity, motivating the need for noise tolerant circuit design. In a 0.351m CMOS technology and at a given supply voltage, the proposed technique provides an improvement in noise-immunity of 1.8X(for an AND gate) and 2.5X(for an adder carry chain) over domino at the same speed. A multiply-accumulate circuit has been designed and fabricated using a 0.351m process to verify this technique. Experimental results indicate that the proposed technique provides a significant improvement in the noise immunity of dynamic circuits ( 2.JX) with only a modest increase in power dissipation (15%) and no loss in throughput.

Abstract. Random switching logic (RSL) has been proposed as an efficient countermeasure to mitigate power analyses. The logic style equalizes the output transition probabilities using a random mask-bit. This manuscript, however, will show a successful attack against RSL. The single mask-bit can only add one bit of entropy to the information content of the overall power consumption variations and can very easily be deduced from the power consumption. Once the mask-bit is known, the a posteriori probabilities of the output transitions are not equal anymore and power analyses can be mounted. A threshold filter suffices to remove the additional bit of information. 1

Accurate power consumption estimation of a System-on-Chip (SoC) using modeling techniques is difficult due to the diverse mixture of processes with radically different current consumption. It is very important that these estimations will be fine tuned to the specific SoC with accurate current measurement during the design and prototyping phase. We introduce an accurate method to measure power consumption using a single measurement point and a dynamic logging algorithm. We present a demonstration tool for continuous logging of the instantaneous power consumption with an identification of the running process within the SoC. Our approach can also be used to steer the dynamic power management (DPM) of a SoC. 1.

We present a low bandwidth protocol for wireless multi-media terminals targeted towards low power consumption on the terminal side. With the widespread use of portable computing devices, low power has become a major design criterion. One way of minimizing power consumption is to perform all tasks, other than managing hardware for the display and input, on a stationary workstation and exchange information between that workstation and the portable terminal via a wireless link. A protocol for such a system that emphasizes low bandwidth and low power requirements is presented herein. Such a protocol should address the issue of noisy wireless channels. We describe error correction and retransmission methods capable of dealing with burst error noise up to BERs of 10 \Gamma3 . The final average bandwidth required is 140Kbits/sec for 8-bit color applications. 1 Introduction Recent years have seen a dramatic increase in the demand for computational resources. The major trend in recent year...

A significant contributor to the total energy consumed on many battery-powered mobile devices is the wireless network interface card (NIC). Therefore, minimizing the energy consumption of the NIC can result in significant battery life improvement for a mobile device. One way of achieving this is to transition the NIC to a lower-power sleep mode when possible For example, the IEEE 802.11 wireless LAN standard power-saving mode (PSM) makes access points bu#er data destined for a client and uses a periodic beacon to inform the mobile client about any bu#ered data. This allows the NIC to enter sleep mode between beacons.

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