Abstract—We describe a distributed position-based network protocol optimized for minimum energy consumption in mobile wireless networks that support peer-to-peer communications. Given any number of randomly deployed nodes over an area, we illustrate that a simple local optimization scheme executed at each node guarantees strong connectivity of the entire network and attains the global minimum energy solution for stationary networks. Due to its localized nature, this protocol proves to be self-reconfiguring and stays close to the minimum energy solution when applied to mobile networks. Simulation results are used to verify the performance of the protocol. Index Terms — Distributed algorithms, energy management, graph theory, mobile communication, network fault tolerance, networks, packet radio, portable radio communication, power measurement, protocols, radio repeaters. I.

Recently, a cost aware metric for wireless networks based on remaining battery power at nodes was proposed for shortest-cost routing algorithms, assuming constant transmission power. Power aware metrics where transmission power depends on distance between nodes, and corresponding shortest-power algorithms were also recently proposed. We define a new power-cost metric based on the combination of both node's lifetime and distance based power metrics. We investigate some properties of power adjusted transmissions, and show that, if additional nodes can be placed at desired locations between two nodes at distance d, the transmission power can be made linear in d as opposed to d a dependence for a2. This provides basis for power, cost, and power-cost localized routing algorithms, where nodes make routing decisions solely on the basis of location of their neighbors and destination. Power aware routing algorithm attempts to minimize the total power needed to route a message between a source...

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A 900 MHz low-noise amplifier (LNA) utilizing three monolithic transformers to implement on-chip tuning networks and requiring no external components has been integrated in 2.88 mm 2 in a standard digital 0.6 m CMOS process. A bias current reuse technique is employed to reduce power dissipation, and process-, voltage-, and temperature-tracking biasing techniques are used. At 900 MHz, the LNA dissipates 18 mW from a single 3 V power supply and provides 4.1 dB noise figure, 12.3 dB power gain, 00033.0 dB reverse isolation, and an input 1-dB compression level of 00016 dBm. Analysis and modeling considerations for silicon-based monolithic transformers are presented, and it is shown that a monolithic transformer occupies less die area and provides a higher quality factor than two independent inductors with the same effective inductance in differential applications. I. INTRODUCTION F INE-LINE CMOS technology easily provides high frequency active devices for use in RF applications (e...

Recent papers reporting CMOS RF building blocks have aroused great expectations for RF receivers using deepsubmicron technologies. This paper examines the trend in CMOS scaling, in order to establish the required current levels and achievable performance for different feature sizes, if robust, easily manufacturable designs are to be implemented for cellular applications. The boundary conditions (system-level constraints) for such designs, in terms of the number of trimmed and untrimmed external components and the roles they play in relaxing active circuit requirements, are emphasized throughout to make comparison of active RF circuits meaningful. At 1 GHz, 0.25- m CMOS appears to be the threshold for robust, low-NF RF front ends with current consumption competitive with today's BJT implementations. Index Terms---CMOS RF, low-noise amplifier, low-power design, mixer, prescaler, RF-IC, technology scaling, wireless communication. I. INTRODUCTION S CALING of CMOS technologies has defie...

Internet-based mobile ad hoc network (IMANET) is an emerging technique that combines a mobile ad hoc network (MANET) and the Internet to provide universal information accessibility. Although caching frequently accessed data items in mobile terminals (MTs) improves the communication performance in an IMANET, it brings a critical design issue when data updates. In this paper, we analyze several push and pull-based cache invalidation strategies for IMANETS. Aglobal positioning system (GPS) based connectivity estimation (GPSCE) scheme is first proposed to assess the connectivity of an MT for supporting cache invalidation mechanisms. Then, we propose a pull-based approach, called aggregate cache based on demand (ACOD) scheme that uses an efficient search algorithm for finding the queried data items. In addition, we modify two push-based cache invalidation strategies, proposed for cellular networks, to work in IMA-NETS. They are called modified timestamp (MTS) scheme and MTS with updated invalidation report (MTS + UIR) scheme, respectively. We compare the performance of all these schemes as a function of query interval, cache update interval, and cache size through extensive simulation. Simulation results indicate that the ACOD scheme provides high throughput, low query latency, and low communication overhead, and thus, is a viable approach for implementation in IMANETS.

Abstract- This paper presents an overview and comparison of CMOS low noise amplifier (LNA) architectures. A brief review of noise figure and linearity is presented to give the reader some background into typical performance measures of LNAs. A traditional radio frequency (RF) receiver architecture is presented and LNA performance is related to overall receiver performance. Recent CMOS LNA performance comparisons are made and a representative LNA architecture is reviewed. The two highest performance CMOS LNAs to date (introduced at ISSCC 2001) in terms of noise figure and linearity are reviewed. Finally, a predicted low-voltage CMOS architecture based on an innovative bipolar archi-tecture is presented. I.

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Abstract — This paper considers the problem of maintaining the coverage degree of a wireless sensor network at an application specific level while keeping the sensing units of only a subset of sensor nodes active at any time to save energy. Two distributed coverage service protocols are proposed, namely NCP (Neighbor- Based Coverage Protocol) and GCP (Grid-Based Coverage Protocol), which identify redundant sensor nodes for the desired degree of coverage to turn off their sensing units. NCP introduces a novel method for evaluation of the coverage degree of a node’s sensing region by its neighbors to determine its redundancy. GCP explores the idea of dividing the target area using a virtual hexagonal-grid during which all but one sensor node with the highest residual energy are identified as redundant for the coverage of the corresponding grid unit. Performance evaluations show that both protocols result in significant energy savings while providing differentiable coverage service in the wireless sensor network with low message and computational overhead. I.

This paper presents a 115-mW Global Positioning System radio receiver that is implemented in a 0.5-m CMOS technology. The receiver includes the complete analog signal path, comprising a low-noise amplifier, I-Q mixers, on-chip active filters, and 1-bit analog-digital converters. In addition, it includes a low-power phase-locked loop that synthesizes the first local oscillator. The receiver achieves a 2.8-dB noise figure (prelimiter), a 56-dB spurious-free dynamic range, and a 17-dB signal-to-noise ratio for a noncoherent digital back-end implementation when detecting a signal power of 0130 dBm at the radio-frequency input. Index Terms--- Active filters, CMOS amplifiers, CMOS radio receiver, Global Positioning System, low-IF receiver, low-noise amplification, mixers, radio receiver, satellite communications, single-chip radio, wireless communications. I. INTRODUCTION T HE Global Positioning System (GPS) comprises 24 satellites in low earth orbit that continually broadcast their po...