Patent battle

ATMI Inc subsidiary, Advanced Technology Materials Inc has filed suit against Praxair Inc, the parent company of Praxair Electronics, charging it with infringement of two patents relating to sub-atmospheric gas delivery technologies used in semiconductor fabrication processes.This is a short news story only. Visit www.three-fives.com for the latest advanced semiconductor industry news.     

The battle for the desktop [network computers]

This article describes how, with a new type of machine called the network computer, or NC, a group of upstarts wants to muscle in on the personal computer's turf. The author examines whether this type of computer, designed from the outset to work on a network, can topple the PC's dominance of the workplace and details how the masterminds behind the PC are fighting back-with the even newer NetPC     

Demand for data communications

The published facts about traditional data communications are assembled, with a view to combining this information with similar information about voice and video, to obtain an overall view of telecommunications traffic and revenues. The data presented are in the form of national aggregates. The information is used to estimate public and private network data communication revenues for the next five years     

Integrated circuits for communications

Wireless communication standards have progressed greatly over the past decade, from the relative simplicity of Bluetooth, to the much more sophisticated Global System for Mobile Communications (GSM) standards that make up a large part of today's cellular communication networks. Perhaps the most interesting aspect of this progression is the accompanying reduction in cost of the wireless devices themselves, driven by numerous innovations in the fields of complementary metal oxide semiconductor (CMOS) process technology, radio frequency (RF)/analog circuit design, and system-on-chip (SoC) integration. In this issue of the Integrated Circuits for Communications Series, we have selected three articles that highlight the challenges in the design of highly integrated SoCs using standard low-cost CMOS process.     

Multimedia communications for users

Research on next-generation multimedia communications services and technologies within a highly interdisciplinary research program that encompasses behavioral science, computer science, and electrical engineering is discussed. The authors state that they have taken an approach to their research that allows the needs of users and the demands of end-to-end applications to shape the future of the multimedia communications network. They use several examples to show how such a perspective affects the development of practical, advanced communications services. These examples span a wide range, including: empirical studies of people's use of technology to communicate in collaborative work settings; the design of software supporting the real-time network delivery of interactive multimedia documents for casual information users in the home; and the creation of next-generation prototypes that support the transmission and viewing of multimedia information in homes, offices and classrooms     

Turbo-MIMO for wireless communications

This article reviews an important class of MIMO wireless communications, known collectively as turbo-MIMO systems. A distinctive property of turbo-MIMO wireless communication systems is that they can attain a channel capacity close to the Shannon limit and do so in a computationally manageable manner. The article focuses attention on a subclass of turbo-MIMO systems that use space-time coding based on bit-inter-leaved coded modulation. Different computationally manageable decoding (detection) strategies are briefly discussed. The article also includes computer experiments that are intended to improve the understanding of specific issues involved in the design of turbo-MIMO systems.     

Technologies for multimedia communications

A number of technologies-based upon the sensory modalities of sight, sound, and touch-are becoming well enough established that their coordinated application can expand capabilities for human/machine interaction. This paper examines evolving advances in natural language communication with machines, video, and audio compression, spatially realistic conferencing, tactile interaction, and high-speed data communication. It considers the integration of these technologies into networked information systems to achieve synergistic benefits for the human user     

Modulators for optical communications

This paper reviews the field of high-speed small-aperture modulators for applications in optical communications, with emphasis on electrooptic modulation. The capabilities and limitations of electrooptic modulators are discussed based on a review of the physical origin of the electrooptic effect. Thermal and photoconduction phenomena, which may severely limit the operation of practical devices, are emphasized. The modulation power and bandwidth limitations using various schemes of electrooptic interaction are derived and compared. It is shown that lumped modulators are capable of efficient modulation for bandwidths up to about 1 GHz for visible wavelengths and are also attractive for their simplicity. For broader bandwidth capability the traveling wave or zigzag types of interaction become more efficient but with added complexity. Finally, acoustooptic and magnatooptic modulators are briefly discussed and compared with electrooptic modulators.     

Surface-acoustic-wave devices for communications

Surface-wave components have demonstrated performance capabilities in the VHF/UHF range which are available with no other filtering technique. The major advantages of the filters are their small size, high reliability, low cost, high Q, good reproducibility, temperature stability, wide dynamic range, and linear phase response, as well as special characteristics relevant to specific applications. Surface-acousticwave (SAW) devices are used for bandpass filtering [1], matched filtering for radar pulse compression [2], [3] or spread-spectrum signal processing [4], delay lines [5], and frequency control elements [3], [6]. Within the context of communication systems' applications, this paper reviews the state of the art for SAW components from high-performance fixed-tuned devices to tunable or programmable filters. Major technological advances discussed include unidirectional SAW filters [7] which eliminate bidirectionality loss and simultaneously suppress in-band spurious responses to achieve an insertion loss below 1 dB with a 0.04-dB peak-to-peak ripple. A novel surface-wave sub-system [8] which offers revolutionary signal processing functions through transform processing is also described.     

Technologies for global communications

Some of the technological breakthroughs underlying today's global communication are reviewed, and the relationship between business needs and the evolution and revolution of telecommunications technology is discussed. The introduction of trans-Atlantic transmission cables and the advent of satellite transmission are described. The role of photonics in reducing transport cost and improving quality and the development of information storage and processing techniques that use various voice and video applications to take advantage of this processing power are outlined. The development of global intelligent networks consisting of a distributed switching fabric with both the local switches and the long distance/international gateway switches interconnected and communicating among themselves with standardized common channel signaling protocols and the applications of such networks are also reviewed     

Building the FO infrastructure for wireless communications

The next generation of communication systems will provide consumers with a host of new and improved voice, video, and data services. Rapidly developing wireless radio systems are already contributing to the progress, giving consumers the luxury of tetherless access to telephone conversation, on-line computing, and cable-television. Indeed, wireless access to high quality information and entertainment is quickly becoming a key component of the information superhighway. In that context, optical fiber links, which have the bandwidth for providing users with the service of their choice, are an excellent connecting infrastructure for providing uniform radio coverage in wireless networks. Indeed, fast improving analog FO links will serve such networks well. In this article, we will analyze the requirements for such a system     

The battle for the SX-70 [camera integrated circuitry]

The story of the struggle between Fairchild Instruments and Texas Instruments for the contract to supply the integrated circuitry for Polaroid's SX-70 camera, introduced in 1972, is related. Research and development work by both companies is described. The problems caused by Polaroid's secrecy regarding the overall camera design are highlighted     

军用柔性显示器的发展

美国军队长期以来一直肯定显示技术在军队系统中所发挥的重要作用,持续支持发展当前的平板显示技术。可折叠显示技术可提供一个比玻璃基显示器更有利的军队应用,因此,美国军队正在支持柔性显示器的研发设计以加速其商品化进程。     

Squeezed light for coherent communications

Coherent lightwave communications systems are approaching a limit where the error rates and channel capacities are limited by the quantum properties of light. This is often referred to as the shot-noise limit. If ideal laser light is used in the system, there is no way to avoid this limit. However, new states of the light field called squeezed states have recently been developed that allow an improvement in error rates below the shot-noise limit. Squeezed light concepts and recent experiments are reviewed with emphasis on aspects important to coherent communications. It is shown that channel capacity can be improved using squeezed light by only a factor of two. Larger improvements are in principle possible for error rates, e.g. a factor of three reduction in the number of required photons per bit for a 10^-9 bit error rate. An example of a recent high-performance system is described where optical losses and electronic noise reduce the improvement expected using squeezed light to the 10-20% level. It is concluded that squeezed light only offers significant improvement in bit error rates for very-high-efficiency systems     

TCP extensions for space communications

The space communication environment and mobile and wireless communication environments show many similarities when observed from the perspective of a transport protocol. Both types of environments exhibit loss caused by data corruption and link outage, in addition to congestion‐related loss. The constraints imposed by the two environments are also similar – power, weight, and physical volume of equipment are scarce resources. Finally, it is not uncommon for communication channel data rates to be severely limited and highly asymmetric. We are working on solutions to these types of problems for space communication environments, and we believe that these solutions may be applicable to the mobile and wireless community. As part of our work, we have defined and implemented the Space Communications Protocol Standards‐Transport Protocol (SCPS‐TP), a set of extensions to TCP that address the problems that we have identified. The results of our performance tests, both in the laboratory and on actual satellites, indicate that the SCPS‐TP extensions yield significant improvements in throughput over unmodified TCP on error‐prone links. Additionally, the SCPS modifications significantly improve performance over links with highly asymmetric data rates. This revised version was published online in June 2006 with corrections to the Cover Date.     

Satellite systems for personal communications

A number of industrial groups are planning to construct satellite systems to provide personal communications services (typically voice, data, and fax) to users who will employ small, hand-held, cellular-type telephones. Some of these systems (e.g., Iridium and Globalstar) will be constructed using satellites in low Earth orbit. Two (Odyssey and ICO) will employ medium Earth orbit (six-hour period), and still others (ACeS and Agrani) will operate from geostationary altitude. The origin and evolution of mobile satellite communications is discussed first, including the INMARSAT system and several land-based mobile satellite systems in operation. The rival approaches to the personal communications services (PCS) market are then described, and some of the technical challenges inherent in each are indicated. The paper concludes with speculation on the factors influencing the likelihood of business success for the various PCS systems     

Coding for meteor burst communications

The use of error correction coding for meteor burst communications is discussed. The cutoff rate is derived for a meteor burst channel model which assumes that the received signal amplitude decays exponentially. The message error rate of a coded system, obtained by means of computer simulation, is compared to that of an uncoded system. A tight upper bound on the performance of the coded system is presented. It is shown that coding can reduce the signal-to-noise ratio (SNR) required for reliable communications via meteor bursts by many decibels. The coding gain is larger at shorter communication ranges where meteor trails, decay faster. It is also shown that the additional improvement achieved by providing the decoder with side information on the instantaneous level of the received signal is small