Joint Phase Time Array: Opportunities, Challenges, and System Design Considerations

Engineering schools generally do a very good job teaching the fundamentals of water distribution system design. However, there are a good number of practical considerations in system design that seem to be ignored in the research literature. This paper attempts to present some important considerations in system design that are important but generally are overlooked in many research papers. Some of the considerations that are described in this paper include the types of water system planning; sources of funding and their effects; dealing with uncertainty, especially in demand forecasts; construction sequencing; and other issues that must be considered in design. The paper focuses on practices common to the United States but most of the content should be relevant in other locations. System design is driven by the need to reliably provide adequate water to customers at adequate pressure and quality while maintaining water rates (customer prices) at a reasonable level. In the early days of centralized water systems, this involved tedious manual calculations and conservative designs. As computer technology advanced, hydraulic analysis models relieved engineers from tedious calculations and enabled them to consider much more detail and perform more analyses to arrive at generally better designs. Researchers have prepared hundreds of papers on application of optimization of water system design, mostly focusing on pipe sizing. While these papers can provide some insights to practicing engineers, real-world details often need to be neglected to force the real problem to acquiesce to the optimization formulation, which usually involves minimizing some objective function(s) subject to some constraints. Hopefully, this paper can point out some considerations that need to be accounted for in any analysis of water system design. Each consideration is described with its implications in the following sections.

At the present time the task of designing a highly integrated ZigBee radio frequency (RF) receiver with an excellent coexistence performance is still very demanding and challenging. This paper presents a number of system issues and design considerations for a ZigBee RF receiver, namely IEEE 802.15.4, for coexistence with wireless devices in the 2.4-GHz ISM-band. With regard to IEEE 802.15.4, the paper analyzes receiver performance requirements for; system noise figure (NF), system third-order intercept point (system-IIP3), local oscillator phase noise and selectivity. Based on some assumptions, the paper illustrates the relationship between minimum detectable signal (MDS) and various situations that involve the effects of electromagnetic interference generated by other wireless devices. We infer the necessity of much more stringent specification requirements than the published standard for various wireless communication field environments

Mobile communications systems will evolve towards a third generation at the beginning of the new millenium. Third generation is built on the backward compatibility with the second generation networks. Thus wideband multi-standard receivers, which are able to operate according to multiple mobile communication standards, will be required by the third generation system users. This paper presents a number of system issues and design considerations which are involved in the design of wideband multi-standard DCS1800/UMTS digital receiver, and in particular the analog-to-digital converter (ADC) technology requirements for the implementation is presented.

Nowadays the design of highly integrated single-chip digital audio broadcasting (DAB) receiver RF front-ends with excellent performance is very demanding and is still challenging. This paper presents a number of system issues and design considerations, which are involved in the design of such a front-end from the system point of view. These considerations include the proper choice of receiver front-end architecture, selection of intermediate frequency (IF) and local oscillator (LO) tuning range and their trade-offs, and critical system performance issues including sensitivity, noise figure, adjacent channel rejection, image rejection, dynamic range and AGC operation, carrier frequency offset, LO phase noise, non-linearities and selectivity and carrier to noise ratio (C/N). The main characteristics and performance of several reported DAB front-end ICs are tabulated.

Ultra Wideband Demystified: Technologies, Applications, and System Design Considerations is a comprehensive text for emerging high speed short range wireless technology of Ultra Wideband. It provides background concepts and information on evolving standards and their development efforts, radio technology, practical system design/implementation and real life applications. The book also deliberates on the regulatory frameworks, security aspects and power management techniques essential to Ultra Wideband usage in consumer devices like portable handheld mobile devices. Important topics as UWB common radio usage for adapting to different existing/new applications and upper layer protocols like Wireless USB are also discussed.ContentsAbstract :• Introduction to Short Range Wireless;• Introduction to Ultra Wideband;• Evolution of UWB Standards;• Physical Layer;• Medium Access Layer;• Advanced MAC Features;• UWB System Design;• Adaptation to Multiple Applications;• Wireless USB;• Converging Marketplace; ReferencesForeword"This book is very timely, unique and fresh in its approach, coming from engineers who have been involved in system design and standard development stages. In particular, the book stands out amongst other literature available because it highlights system designer's viewpoints and because of it covering the whole gamut of technology from practitioner's viewpoints ... I would strongly recommend this book to System Designers, Practicing Engineers, Researchers in Academia and Industry, Product Marketing and Technical strategists for a comprehensive reading on the emerging UWB technologies. I commend Sunil Jogi and Manoj Choudhary for a very timely contribution."Bart Vertenten Chief Architect Connectivity, NXP Semiconductors

Rising costs of artificial lift operations are a continuing concern to oil producers in maintaining efficient and profitable performance. A new long-stroke sucker rod pumping system has been developed to minimize the impact of these rising costs. This new system results from a broad development project based on system design considerations having major influence on overall cost effectiveness of the system. The basis of these evaluations is discussed, resulting equipment design is described, and field operating results are presented. Performance results to date confirm achievement of reduced overall operating costs as a result of the performance characteristics of this system.

Design considerations for subscriber multiplexed (SCM) systems distributing multichannel analog/digital signals are reviewed. In particular, video distribution schemes based on lightwave transmission technologies are discussed. The two most important system design considerations in an SCM system are the control of intensity noise and nonlinear distortions. Intensity noise characteristics and degradation caused by optical reflections are discussed. Laser and detector linearity requirements are reviewed. System signal-to-noise ratio analysis is performed. Design considerations for receivers for SCM systems are reviewed, and various system applications are examined. >

With the proliferation of so-called smart components and the availability of small, low-cost, and high-speed data networks, avionics that have traditionally been centralized are becoming distributed. A distributed approach offers many potential benefits and can reduce the risk associated with design errors by splitting complex hardware and software into more manageable components. However, distributed systems also introduce new challenges in meeting real-time deadlines and providing fault tolerance. The automotive industry is addressing the challenges with the development of distributed, drive-by-wire systems, and the adaptation of these to avionic applications looks promising. In developing these new distributed systems, there are many fundamental system design considerations including: time or event-triggered data communication, distributed or centralized data network control, need and method for time-synchronization of distributed components, topology and amount of redundancy to provide fault tolerance. This paper examines these design considerations and identifies the strengths and weaknesses of each.

This paper discusses about derivation of potential of regenerative braking from Indian driving perspective and it also evaluates parameters useful for system design using data analysis. The fuel efficiency potential and other calculation results are based on Indian homologation cycle and collection of real world driving data which was condensed into meaningful drive cycles for prominent Indian cities. Component and control strategy requirements are calculated and the compromises that would result due to the calibrations in strategy are quantitatively defined. This enables the engineers to make concrete data driven decisions during system design. The paper also discusses incorporating safety related considerations in system design e.g. Stability during wheel lock, safety from generation at high power, effect of ABS and understanding the effect of an electric regenerative braking system on vehicle chassis behavior while briefly discussing about enhancing regenerative braking potential by changes in system and control design.

MEMS capacitive strain sensors are attractive for a wide range of industrial sensing applications due to their high sensitivity, large dynamic range and low temperature dependence. However, after sensors packaging and attachment to a targeted metallic surface, the overall sensing system can exhibit a substantial package-induced temperature dependence caused by different thermal expansion coefficients of silicon, metallic surface and bonding adhesives, thus degrading overall performance. Temperature characterization from −20°C to 150°C of prototype strain sensing modules attached on a stainless steel surface reveals a temperature dependence of −6.2 μe/°C. As a results, an increased dynamic range of the sensing electronics are required at the expense of an increased system supply voltage as well as power dissipation. A careful system characterization over the operating temperature range and optimized system design considerations are, therefore, critical for achieving stringent performance requirements.

Optical mechanical scanners offer a means for producing imagery from earth orbiting platforms in many wavelength bands simultaneously ranging from the visible to about 13 µm. Since the signal is in electrical form, it can be telemetered to earth where the spectral content of each scene element can be processed to classify features based on their spectral properties. Optical mechanical scanners, electron beam imagery systems, and electronic self-scanning detector arrays are being developed as imaging systems for earth observation from satellites. NASA convened a working group to evaluate the role of these imagers in earth observation programs and assess R&D requirements for future systems. Some of the system design considerations prepared by the electromechanical scanner panel for use by this working group are presented.

Extensive electrical system design considerations are required to implement performance and service tests on Class 1E batteries in accordance with IEEE 450-1980 "Recommended Practice For Maintenance, Testing and Replacement of Large Lead Storage Batteries for Generating Stations and Substations."

Multiple pencil-beam scanning/hopping antenna systems provide a powerful approach to increase the satellite's capacity by the frequency reuse, the increased e.i.r.p. and G/T of each of the pencil beams, and also by the efficient satellite resources utilization through matching the antenna beams' dwelling times to the traffic and connectivity requirments. Since this permits also to use very small and inexpensive earth stations, a significant reduction in cost per communication channel can be obtained. One of the problem areas still existing and requiring an innovative solution is the distribution of the broadband microwave communications and control signals to the very large number of the active antenna moduls. Each module consists of a digital phase shifter and gain control, amplifier, and a radiating element. Recent advances in fiber optics technologies for microwave applications in the over-l0-GHz region, make it a very attractive candidate for signal distribution networks in large satellite antenna arrays. The main advantages of a fiber optic network are the very small size and weight, the capabillity to be integrated with MMIC devices, and immunity to electromagnetic interference, while the main disadvantages are the high insertion loss and high noise figure. In this paper some system design considerations are evaluated, in applying the fiber optic technologies and techniques to multibeam scanning Ku-band satellite antenna signal distribution and control networks. It is demonstrated that the fiber optic links can provide a feasible solution.

This paper presents common system design considerations imposed on magnetic storage devices that employ MEMS devices for positioning of a magnetic probe device over a magnetic media. The paper demonstrates that active servo control of the probe tip to media separation can be achieved with sub-nanometer accuracy. It demonstrates that reasonable-size capacitive sensors can resolve probe tip motions with a noise floor of roughly 22 picometers, allowing them to be used as position sensors in magnetic force microscope (MFM) readout approaches. In addition, this paper demonstrates that although MEMS media actuators can achieve scanning ranges of /spl plusmn/50 um, the mass of the media sled imposes important access time and data rate constraints on such MEMS-actuated mass storage devices.

Railroad environments are generally considered to be among the most dynamic workplace environments, even with constant improvement efforts by the railroad industry. While there has been great progress in equipment safety, personnel safety is a significantly harder challenge. These challenges are primarily derived from the presence of heavy moving machinery in close proximity to personnel and the difficulty of designing reliable wearable protection devices. Additionally, variable weather conditions, challenging walking conditions (ballast, trip hazards, etc.), and difficulty to focus on environment, moving objects, and on tasks at hand place the employees in constant peril. Therefore, our survey is focused on exploring solutions for protecting employees through unified system modeling and design that makes the employee integral to the process and results in personal protective devices that work with the environment and the employee, not against them. The optimal system design integrates not only protection of the employees from falls, unsafe practices, or collisions, but also aids in resource planning, safe operation and accounting of “near-miss” situations. In recent years the railroads have made significant investments in process automation and monitoring solutions such as Wireless Sensor Networks. These technologies are becoming increasingly cloud-connected and autonomous. They provide a plethora of information about equipment positions, movement, railcar lading, and many other factors, all of which are highly useful in the design and implementation of a railyard worker protection system. They allow us to predict position and movement, and can thus be used to provide effective proximity detection and alerting in some railyard regions where these systems are installed. Additionally, we discuss several technologies addressing near-collision, fall, and proximity situations through RF and non-RF-based techniques. The railroad industry has been advancing efforts leveraging these technologies to improve the safety of their workers. However, there are also many challenges that remain largely unaddressed. For example, in railroads, a detailed and exhaustive causation analysis for worker incidents has yet to be conducted. Therefore, in an environment like a railyard there is no solution to detect or prevent Employee on Duty (EOD) fall, collision, or health issues such as dehydration, psychological issues and high blood pressure. Protective devices worn by workers is believed to be one of the most important, cost-effective, and scalable potential candidate solutions. Recent advances are making wearable wireless body area networks (WBAN) and wireless sensor networks (WSNs) that are distributed and large-scale a reality. Such distributed networks consist of wearable sensors, fixed-installation sensors and communication links between all of them. The challenges are found in selecting wearable sensors, researching reliable communication among nodes without interfering with proximity detection and suitable for high-multipath, non-line of sight channel conditions, wearable antenna designs, power supply requirements, etc. A dense, distributed, large-scale environment like a railyard requires comprehensive workspace modelling and safety analysis. Interference related to RF sensor deployment, blind spots in vision-based approaches, and wireless propagation in intra and inter-WBAN communication due to dense non-Line-of-Sight workspace environments, metallic heavy machinery and the use of RF sensors, are all individual research challenges in this domain. This paper reviews these challenges, explores potential solutions, and thus provides a comprehensive survey of a holistic system design approach for a wearable railyard worker protection system that is unobtrusive, effective, and reliable.