Networking together hundreds or thousands of cheap microsensor nodes allows users to accurately monitor a remote environment by intelligently combining the data from the individual nodes. These networks require robust wireless communication protocols that are energy efficient and provide low latency. We develop and analyze low-energy adaptive clustering hierarchy (LEACH), a protocol architecture for microsensor networks that combines the ideas of energy-efficient cluster-based routing and media access together with application-specific data aggregation to achieve good performance in terms of system lifetime, latency, and application-perceived quality. LEACH includes a new, distributed cluster formation technique that enables self-organization of large numbers of nodes, algorithms for adapting clusters and rotating cluster head positions to evenly distribute the energy load among all the nodes, and techniques to enable distributed signal processing to save communication resources. Our results show that LEACH can improve system lifetime by an order of magnitude compared with general-purpose multihop approaches.

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An application-specific protocol architecture for wireless microsensor networks

A 1.5-GHz low noise amplifier (LNA), intended for use in a global positioning system (GPS) receiver, has been implemented in a standard 0.6-/spl mu/m CMOS process. The amplifier provides a forward gain (S21) of 22 dB with a noise figure of only 3.5 dB while drawing 30 mW from a 1.5 V supply. In this paper, we present a detailed analysis of the LNA architecture, including a discussion on the effects of induced gate noise in MOS devices.

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A 1.5-V, 1.5-GHz CMOS low noise amplifier

In recent years, advances in energy-efficient design and wireless technologies have enabled exciting new applications for wireless devices. These applications span a wide range, including real-time and streaming video and audio delivery, remote monitoring using networked microsensors, personal medical monitoring, and home networking of everyday appliances. While these applications require high performance from the network, they suffer from resource constraints that do not appear in more traditional wired computing environments. In particular, wireless spectrum is scarce, often limiting the bandwidth available to applications and making the channel error-prone, and the nodes are battery-operated, often limiting available energy. 
My thesis is that this harsh environment with severe resource constraints requires an application-specific protocol architecture, rather than the traditional layered approach, to obtain the best possible performance. This dissertation supports this claim using detailed case studies on microsensor networks and wireless video delivery. The first study develops LEACH (Low-Energy Adaptive Clustering Hierarchy), an architecture for remote microsensor networks that combines the ideas of energy-efficient cluster-based routing and media access together with application-specific data aggregation to achieve good performance in terms of system lifetime, latency, and application-perceived quality. This approach improves system lifetime by an order of magnitude compared to general-purpose approaches when the node energy is limited. The second study develops an unequal error protection scheme for MPEG-4 compressed video delivery that adapts the level of protection applied to portions of a packet to the degree of importance of the corresponding bits. This approach obtains better application-perceived performance than current approaches for the same amount of transmission bandwidth. These two systems show that application-specific protocol architectures achieve the energy and latency efficiency and error robustness needed for wireless networks. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)

Application-specific protocol architectures for wireless networks

A 1.5 GHz low noise amplifier for a Global Positioning System (GPS) receiver has been implemented in a 0.6 /spl mu/m CMOS process. This amplifier provides a forward gain of 22 dB with a noise figure of only 3.5 dB while drawing 30 mW from a 1.5 V supply. To the authors' knowledge, this represents the lowest noise figure reported to date for a CMOS amplifier operating above 1 GHz.

/pdf/a-1-5-v-1-5-ghz-cmos-low-noise-amplifier-3kbllf072y.pdf

A 1.5 V, 1.5 GHz CMOS low noise amplifier

If you want to get Handbook of Internet Computing pdf eBook copy write by good Handbook of Wireless Networks and Mobile Computing Google Books. Mobile Computing General. Handbook of Algorithms for Wireless Networking and Mobile Computing by Azzedine Boukerche (Editor). Call Number: TK 5103.2. CITS4419 Mobile and Wireless Computing software projects related to wireless networks, (2) write technical reports and documentation for complex computer.

Handbook of wireless networks and mobile computing

In future personal communication services, high-bandwidth multimedia data will be delivered over wireless pico-cellular networks to high densities of users. The system described here is designed to simultaneously supply 1 Mb/s to up to 50 users in a single cell, requiring a system bandwidth in excess of 50 Mb/s. The use of spread-spectrum techniques, in particular direct sequence code-division multiple access (CDMA), provides a multiple-access strategy to maintain parallel, separate streams of real-time data to all users, and to reduce sensitivity to multipath, narrow band fades, and interference present in the radio environment. Three chips in standard digital 0.8 /spl mu/m CMOS technology implement the critical parts of a spread spectrum transceiver: the digital modulator; the analog receiver front-end and ADC; and the digital receiver baseband processor. The transmit system transmitter is based loosely on the US IS-95 digital cellular CDMA standard, but at more than an order of magnitude higher date rate.

A low-power CMOS chipset for spread spectrum communications

Over the past several years, wireless communications have seen dramatic advances in two distinct areas. On one hand, the demand for portable voiceband services has resulted in intense research efforts to improve performance and increase capacity through digital transmission. Such systems focus on wide-area narrowband communications, providing low-bandwidth network services to individual users in a portable fashion. On the other hand, the need for more flexible computer networks has led to the advent of wireless LANs such as the Motorola Altair. Such systems focus on local-area wideband communications, providing networking services to individual computers but usually they are not easily portable. However, the distinction between these two systems is rapidly blurring. As laptop computers place mobile computing resources in the hands of individuals, wireless technologies capable of providing wide-area, wideband services will clearly be needed. With this merging of computation and communications, individual users will have instantaneous and portable access to fixed information networks via a lightweight mobile unit. Furthermore, users will be capable of transferring data to other users and accessing fixed computing resources without any constraints on where or when such access takes place. As shown in the figure, the mobile unit will support a myriad of services, including full-motion digital video and high-quality audio data, and combine the functionality of today's analog mobile telephones, radio pagers, and laptop personal computers.

Lapoe Lynn

Papers

A low-power CMOS chipset for spread spectrum communications

Analog and digital CMOS design for spread-spectrum wireless communications

SP 21.4: A Low-Power CMOS Chipset