Commercial Telecommunication Research Articles

Cabled Ocean Observatory Systems

Future studies of episodic processes in the ocean and earth will require new tools to complement traditional, ship-based, expeditionary science. This will be enabled through the construction of innovative facilities called ocean observatories which provide unprecedented amounts of power and two-way bandwidth to access and control instrument networks in the oceans. The most capable ocean observatories are designed around a submarine fiber optic/power cable connecting one or more seafloor science nodes to the terrestrial power grid and communications backhaul. This paper defines the top level requirements that drive cabled observatory design and the system engineering environment within which a scientifically-capable infrastructure can be implemented. Commercial high reliability submarine telecommunication technologies which will be crucial in the design of long term cabled observatories are then reviewed. The top level architecture of a generic cabled observatory, describing the main subsystems comprising the whole and defining technological approaches to their engineering, is then described, along with some example design choices and tradeoff studies

Fibre-optical features of a glass sponge.

Some superior technological secrets have come to light from a deep-sea organism. Modern technology cannot yet compete with some of the sophisticated optical systems possessed by biological organisms1,2,3. Here we show that the spicules of the deep-sea 'glass' sponge Euplectella have remarkable fibre-optical properties, which are surprisingly similar to those of commercial telecommunication fibres — except that the spicules themselves are formed under normal ambient conditions and have some technological advantages over man-made versions.

Quality of service (QoS) on public telephonic networks for multimedia transmission systems

The object of this paper is to determine which QoS maximum can be obtained by applying commercial telecommunications technology in the transmission of audio and video on public telephone lines and the Internet, procuring to achieve the necessary quality to reach the conditions required on H323. It is certain that the top technology that allows to assure that the QoS is most demanding, are a reality. However, these technologies alone pay off practically under conditions that are not very feasible for formalizing would be of the ambient control of the laboratory. In this work we analyzed the technical problems of the telecommunications that affect the yield of the links for applications of multimedia on the Internet.

Potential exposures and risks from beryllium-containing products.

Beryllium is the strongest of the lightweight metals. Used primarily in military applications prior to the end of the Cold War, beryllium is finding new applications in many commercial products, including computers, telecommunication equipment, and consumer and automotive electronics. The use of beryllium in nondefense consumer applications is of concern because beryllium is toxic. Inhalation of beryllium dust or vapor causes a chronic lung disease in some individuals at concentrations as low as 0.01 microg/m3 in air. As beryllium enters wider commerce, it is prudent to ask what risks this might present to the general public and to workers downstream of the beryllium materials industry. We address this question by evaluating the potential for beryllium exposure from the manufacturing, use, recycle, and disposal of beryllium-containing products. Combining a market study with a qualitative exposure analysis, we determine which beryllium applications and life cycle phases have the largest exposure potential. Our analysis suggests that use and maintenance of the most common types of beryllium-containing products do not result in any obvious exposures of concern, and that maintenance activities result in greater exposures than product use. Product disposal has potential to present significant individual risks, but uncertainties concerning current and future routes of product disposal make it difficult to be definitive. Overall, additional exposure and dose-response data are needed to evaluate both the health significance of many exposure scenarios, and the adequacy of existing regulations to protect workers and the public. Although public exposures to beryllium and public awareness and concern regarding beryllium risks are currently low, beryllium risks have psychometric qualities that may lead to rapidly heightened public concern.

Advances in software defined radio

Progress in software defined radio has been rapid, since the term was first coined in the mid 1990s. In this brief overview we summarise some of the recent advances in software defined radio from a range of technology perspectives — radio frequency design, baseband reconfigurability, reconfigurable applications and protocols and regulatory (and related network) aspects. Our frame of reference for this article is commercial mobile telecommunications, although many of the technology advances are of relevance and application in other arenas, such as defence, satellite communications and broadcasting. Software defined radio has come a long way very quickly, but in reality is still in its infancy — the next decade will see substantially further advances. This paper draws heavily upon two books on this subject recently edited by the author — the contributors to those books are listed at the end of this article and the work of these pioneers of software radio is fully and most gratefully acknowledged. Additional detail on issues covered in this article may be found in specific chapters of these books, referenced as [Name] within the text.

Thermal Management of Outdoor Electronic Cabinets Using Soil Heat Exchangers

Telephone companies utilize densely packed electronics in outdoor metal cabinets for routing calls between customers. As a result of the increasing power densities of electronics, companies are looking for innovative methods of providing system level cooling such as using soil heat exchangers. Numerical simulation using a system of lumped thermal capacitances coupled to a soil finite element model is used to predict the transient thermal behavior of a cabinet. The cabinet model has been verified in previous studies by comparison with experimental measurements on a commercial telecommunications cabinet and is shown to predict temperature trends well. The effects of transient heat load, soil properties, and heat exchanger geometry are examined. Results reveal soil heat exchangers have the capability to provide the necessary cooling for relatively low power outdoor cabinets. However, the temperature of the soil surrounding the heat exchanger may increase daily if the number and spacing of pipes is not adequate to handle the desired heat dissipation load.

Design of a new remote control system for microgravity facilities on board the international space station: preliminary results

The paper deals with the preliminary design of a new system for Telescience operations of microgravity experimentation on-board the International Space Station. The system represents an innovative implementation of new telecommunication system that combined with on-board computer, is able to provide complementary link between the investigator on-ground and the facilities on-board. This new concept is aimed to carry out the following tasks: • to reduce as much as possible the period of loss of the signal, so as to guarantee an almost continuous and real-time control of the experiment; • to reduce the complexity of the network which routes the signal from ISS to the Investigator and vice versa; • to simplify the access procedure to the scientific payloads. In order to obtain such results the system has been designed to be operated with the existing commercial telecommunication satellites for mobile users. The selection of these platforms imposed the utilisation of low bit rate channels, that, however, using data extraction techniques, are compliant with large part of the planned experiments. This scenario has been defined also taking into account a comparative analysis of the possible constellation suitable for this utilisation. A major problem due to the installation on a space platform of a transponder conceived for Earth mobile users is the magnitude and the rate of Doppler shift between the platform and the satellites of the constellation. The required modifications to the transponder have been analysed and a solution is proposed. Utilisation of low bit rate channels represents a strong constraint for data stream, since for a certain number of microgravity experiments the most relevant information is carried in video images. A video link, on the other hand, is an extremely demanding resource, often not available during the complete mission, but only during very limited periods of coverage. From these considerations stems the idea to implement on-board a system able to extract most significant scientific information from experiment images and to transmit only this information over the link (available during all the mission time). In addition, other systems on-ground receive the data and are able to reconstruct a “virtual” image on the basis of the extraction algorithm used. In this paper, techniques that can be applied to this process of “video information extraction” are analysed and discussed. As a test case two algorithms of data extraction from video images of Fluid Science experiments have been developed, together with the on-ground reconstruction software. The algorithms have been tested using images of an experiment carried out during Spacelab LMS mission and the results obtained are presented. Their implementation has shown that this system is suitable for the real-time experiment control, also taking into account that the scientific images can be stored on-board and analysed post-flight for a more accurate scientific evaluation.

An architecture of high-performance frequency and phase synthesis

Frequency synthesis has many applications in today's commercial electronic and telecommunication system design. Some techniques exist which can be used to generate a frequency that is an integer or fractional multiple of a reference frequency. This architecture is used to generate a signal of any desired frequency in a certain range from multiple reference signals with same frequency but different phases. These reference signals may come from a voltage-controlled oscillator (VCO) which is close looped with a reference clock by a phase-lock loop (PLL). This architecture provides some unique features, superior quality, and ease of implementation. In some cases, the synthesized frequency is time-average frequency. The signal can be treated as a carrier signal frequency modulated by another signal. Various phase-shifted versions and duty cycle versions of this signal can also be generated from this architecture. This architecture also has direct application to spread spectrum clock generation.

STENTOR programme: An ongoing and efficient way for preparing the future

Presently, the french governmental bodies and space industry are joining their efforts and investments in a large technological programme named STENTOR; this programme is aiming to improve competitiveness of french space telecom industry by lowering costs and getting quickly vital technologies for the future. First of all, this paper outlines main components of this programme and its major stages since 1994 up to 2009. Most innovating technologies of STENTOR satellite are described in terms of technical performances, development status and very promising impacts on cost and overall performances of future commercial telecom satellites; here is a preliminary list: plasma propulsion, thermal control using fluid loops and a deployable radiator, Li-Ion batteries, orbit determination with GPS receiver. Ku band regenerative payload with active antennas, etc. Finally, some examples of service demonstrations foreseen for the in-orbit operating phase are given as illustrations.

Managing software requirements using quality function deployment

In this article we describe and discuss QFD (quality function deployment) as a framework for managing software requirements. Experiences were gained while participating as researchers in a commercial large-scale software telecommunications project at Ericsson Radio Systems AB. We found that prerequisites for succeeding with QFD include having visible customers and users, forming a cross-functional team adequately trained in QFD, and allowing adequate time for its first application. Advantages of using QFD are: better focus on customers and users, an effective means of prioritizing and communicating software requirements; and managing non-functional requirements. Issues not fully supported by QFD include adequate abstractions levels in describing requirements, handling temporal relations between requirements and initiating the use of QFD for a new development project.

Improved candidate generation and coverage analysis methods for design optimization of symmetric multisatellite constellations

Much attention in recent years has focused on commercial telecommunications ventures involving constellations of spacecraft in low and medium Earth orbit. These projects often require investments on the order of billions of dollars (US$) for development and operations, but surprisingly little work has been published on constellation design optimization for coverage analysis, traffic simulation and launch sequencing for constellation build-up strategies. This paper addresses the two most critical aspects of constellation orbital design — efficient constellation candidate generation and coverage analysis. Inefficiencies and flaws in the current standard algorithm for constellation modeling are identified, and a corrected and improved algorithm is presented. In the 1970's, John Walker and G. V. Mozhaev developed innovative strategies for continuous global coverage using symmetric non-geosynchronous constellations. (These are sometimes referred to as rosette, or Walker constellations. An example is pictured above.) In 1980, the late Arthur Ballard extended and generalized the work of Walker into a detailed algorithm for the NAVSTAR/GPS program, which deployed a 24 satellite symmetric constellation. Ballard's important contribution was published in his “Rosette Constellations of Earth Satellites.”

When and how to assess fast-changing technologies: a comparative study of medical applications of four generic technologies.

OBJECTIVES. To try to identify the optimal time at which to start assessing new and fast-evolving health technologies. To provide insight into factors influencing the timing of assessments and the choice of methods for assessing new and fast-changing technologies. HOW THE RESEARCH WAS CONDUCTED. A series of literature reviews were undertaken covering the general principles involved in the timing of health technology assessments (HTAs). Additionally, the reported assessments of laparoscopic cholecystectomy, chorionic villus sampling (CVS), teleradiology, teledermatology, genetic screening for predisposition to breast cancer, and gene therapy for cystic fibrosis were reviewed to try to identify the factors that influenced the timing of these assessments. Key individuals in each field were also interviewed. The selected technologies allowed comparison between those that were new and evolving and those that were relatively well-established. A bibliometric study of publication trends was also undertaken to see whether these trends would suggest points in the development of a technology that could be used as indicators that assessment should be started. RESEARCH FINDINGS. TIMING. The precise point at which assessment should start was not identified but the bibliometric study suggested that extending this approach might give useful results. For all health technologies, more regular reporting of outcomes and side-effects should be encouraged during the period after initial assessment and, where the technology is fast-changing, reassessment should take place from time to time. The precise intervals were not identified and the problem remains of deciding when a technology has changed enough to warrant reassessment. FACTORS INFLUENCING TIMING. Published reports of assessments did not generally specify the reasons for their timing, but a number of factors appear to have influenced the timing of those assessments, directly or indirectly. Product champions and opinion leaders pioneer the introduction of new technologies into clinical practice, and their reports may lead to the rapid diffusion of such technologies before they have been adequately evaluated, as was the case with laparoscopic cholecystectomy; this diffusion may limit the methods of evaluation that can then be used. It is therefore important to assess new health technologies before diffusion takes place. The extent to which regulatory control is imposed on the introduction of new health technologies can also influence the timing of assessments. Such controls might have helped to restrict the diffusion of laparoscopic cholecystectomy, making a large and widely generalisable randomised controlled trial (RCT) feasible. The source and availability of funding for studies may influence the nature and timing of trials. Many telemedicine evaluations were funded by commercial telecommunications organisations and were thus restricted in their timing (and biased towards the technological aspects of the applications) by the availability of funds. Media coverage undoubtedly has an influence although this influence is not always predictable; it may generate 'favourable' publicity about new health technologies, which can lead to immediate demands for the new technique, as was the case with laparosocpic cholecystectomy with its apparent benefits. Thus assessments should be made before media coverage exerts popular pressure on purchasers to adopt the technology and dissuades patients from participating in RCTs (because of fear they may be randomised to the standard treatment as occurred in a US trial of CVS). Innovators should also be cautious in the claims that they make to the media.(ABSTRACT TRUNCATED)

A multimedia manual on the World Wide Web for telecommunications equipment

An interactive multimedia educational manual on the Internet through the World Wide Web for commercial optical fiber telecommunications equipment is described. The Telecommunications Laboratory Manual is a vehicle for enhancing engineering education with realistic laboratory or virtual laboratory experience. The manual provides a brief system tutorial, operating instructions, online help, and multimedia experimental demonstrations. It incorporates block diagrams, photographic images, and hypertext links that are mouse clickable, allowing users to access documents or links describing components or processes in any order. An experimental section guides students through laboratory experiences, demonstrates selected equipment characteristics, and provides for direct instructor contact through e-mail. Other remote resources on the Internet are linked to create a global multimedia library. This paper describes the manual, its multimedia design, its use in the curriculum, and its further potential.

The measurement of commercial telecommunication satellite prices

The measurement of commercial telecommunication satellite prices

Reframing the TVNZ Debate

In 1989, New Zealand's public television corporation was restructured as a state-owned commercial telecommunications enterprise. Its news department became a self-funding 'strategic business unit' or profit centre within an organisation which was now concerned with establishing itself as a serious contender in the international telecommunications market. The debate over TVNZ news has typically revolved around the question of how well audiences are informed by such programming, and the differences in public service and commercialised news discourse and the implications for public opinion on political issues. In this paper, it is argued that understanding of these important issues is impaired because the underlying model of news fails to contextualise television news in the actualities of its social uses and meanings within the everyday world.

Women Library Users and Library Users of Traditional Women's Subjects

In the studies of general library use, women use libraries more than men. When use studies of particular subjects are done, women nearly always are more likely to use libraries for information on that subject than men. Yet there are few studies on women's information needs or use studies of traditional women's subjects. When women's subjects are written about in the library literature, the articles are nearly always on collection development, not on information needs. Information on women's subjects is primarily requested in public libraries and is not considered worthy of scholarly concern. Five specific categories of women's subjects: traditional women's subjects like needlework, practical information for the home, information related to a change in life like returning to school or to work, information on women's health issues, and information about parenting are reviewed. Current trends in commercial electronic information systems and telecommunications technology make the issue of information needs research and analysis urgent.

Communications for the digitized battlefield of the 21st century

Technology base investments by the US Army will exploit the wealth of emerging commercial telecommunications services, as an operational supplement to classical tactical communications systems. This paper presents a series of technology components that collectively form the basis for the Army's Battlefield Information Transmission System and will provide the underlying seamless, global, "ubiquitous" transmission system for the Force XXI warfighter. The technical and system architectures of the 21st century will evolve through a gradual process of development, acquisition, and experimentation. This process, by definition, is a combined effort relying on the Army Materiel Command (AMC) Research, Development and Engineering Center (RDECs) working with the TRADOC battlelabs. The battlelabs, through a formal series of Advanced Warfighting Experiments (AWEs), play a crucial role in testing and adapting the technology produced by the AMC RDECs and commercial providers. Commercial technology is also directly exploited in TRADOC user environments as part of the Army's ACT II program.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Direct global marketing using radio amateur packet switched network

The E-form is a kind of standardized electronic message with the potential to greatly simplify and facilitate exchanges of information on a telecommunications network. One especially promising use is to ease the problem of automatic language translation in transactions between people who speak different languages. With such a capability, direct mail marketing could go global. A commercial telecommunications and information infrastructure that could best make use of E-forms does not yet exist. But it is possible to begin to explore now the power and essential role of E-forms: the radio amateur community already has in place a global digital packet-switched information network conducive to an evaluation of the E-form concept. In this paper the concept of the E-form is discussed. Next the radio amateur packet-switched network is introduced and described, and the implications of broadcast (list) message traffic on a commercial network are explored.

An expert system for network management control

Abstract Due to the varying time and the complexity of the commercial telecommunication network configuration, routing of the communication traffic becomes very important for telecommunication systems. No one can keep in mind all the complex routing plans used in networks, so it is hard to quickly take proper actions while the switching node is being blocked. In this paper, we propose an expert system which can collect traffic data, monitor network status, reason and take appropriate actions for extreme traffic congestion on a network just as a network management expert can do. It would certainly streamline the whole network control procedure, and. provide dynamic routing functions based on the original static routing method adopted in Taiwan. It does improve both network efficiency and network reliability.

Some recent developments in circular overmoded waveguide

Progress is described in the theoretical modelling, design and testing of overmoded circular TE01 mode waveguide applicable to high power, low loss transmission in the microwave and lower millimetre wave bands. Theoretical techniques, originally developed to model low loss millimetre band waveguide for commercial telecommunications, have been adapted to overmoded sheathed-helix waveguide (with continuous unwanted-mode suppression) subject to new constraints of tighter bend radius relative to the wavelength, high power and significantly less overmoding. Numerical design analysis using coupled mode theory has yielded helix waveguide designs which have been experimentally verified.