Telecommunication Lines Research Articles

Surge Protection for On-Hook and Off-Hook States of Communication Equipment Connected to the Telephone Networks

Telecommunications facilities with the advance of highly information-oriented society requires a higher transmission rate, LSI and VLSI circuits based on semiconductor technologies are widely used in communication devices. Modern microelectronic circuits may be susceptible to damage by lightning surges. Therefore, the protection of electronic circuits from lightning surges is highly interested. Applications of surge protective devices(SPDs) are to protect communication facilities from lightning surges. The operating characteristics of the telephone network are divided into the on-hook state and the off-hook state. A subscriber protector is normally installed telecommunication lines, but it limits the incoming lightning surges to the protection level of the on-hook state. Thus the protection of telephone from overvoltages in the off-hook state is not achieved. In this paper, in order to solve the above points, the hybrid surge protective circuit of protecting the telephone from overvoltages in off-hook and on-hook states was designed. The operating characteristics of the proposed surge protective circuit were experimentally analyzed and discussed.

Новые виды войн и безопасность России

<p>В статье дан социально-философский анализ войн нового поколения. Показано, что в условиях однополярного мира и доминирования США на мировой арене наряду с опасностью ядерной войны резко возросла угроза войн нового поколения: экономических, «элитных»; сетецентричных, информационных, кибервойн. Речь идет о повышении роли невоенных факторов, направленных на разрушение социальных и экономических основ другого государства, его окружения, культурных и духовных ценностей, общественного уклада и политического режима с помощью новых средств борьбы и видов оружия. Подчеркивается, что ныне Россия столкнулась с очень серьезным вызовом — угрозой войны и в прежних, и в новых форматах.</p><p>В условиях глобализации широкое распространение получили экономические войны. Ведущие страны стремятся к достижению своих целей на мировой арене воздействием на политику других государств экономическими методами, например введением экономических санкций. В современных «элитных» войнах широко используются новейшие достижения прикладной психологии, которые позволяют точно реконструировать личности лидеров, выявлять их сильные и слабые стороны, а также прогнозировать их возможные действия. Не меньшую угрозу для России в настоящее время представляет вид сетевых войн, имеющих военное происхождение. Их особенностью является то, что в них невоенными средствами достигается реальная военная победа, осуществляется захват территорий и устанавливается контроль над ними.</p><p>Информационная война представляет собой одну из новых форм борьбы между государствами, а также систему мер, осуществляемую одним государством с целью подрыва информационной безопасности. Если главными объектами воздействия и защиты при информационно-технической борьбе являются информационно-технические системы (системы связи, телекоммуникационные системы, радиоэлектронные средства), то при информационно-психологической борьбе — психика политической элиты и населения противостоящих сторон, системы формирования общественного сознания, мнения, выработки и принятия решений. Особый вид информационно-технической войны представляет собой систему мер, направленных на достижение информационного превосходства путем воздействия на информацию и информационные системы противника при одновременной защите собственной информации и своих информационных систем. Виртуальное пространство, киберпространство стало еще одним пространством, в котором проходят конфликты. </p>

Service Quality in the Telecommunication Industry: Analysis with Special Reference to DSL Services

The research study was conducted to analyze the service quality in the telecommunication sector because in the present intensive broadband market, the survival of wire line telecommunication sector depends on the service quality offered to the end user that serves as a key tool for competition and survival. Though there exist various constructs to measure service quality, the study used performance items of service quality, and survey method was used to collect data from the sample. Based on the analysis, the tiered classification of service quality was represented, which gave a clear scheme for the telecom service providers to identify the service quality attributes that leads to enhancement in their performance in a highly competitive market.

Protection of Digital Telecom Exchanges Against Lightning Surges and Earth Faults

Low-power electronic devices used in digital telecom exchanges are vulnerable to surge voltages and currents primarily originating from natural lightning or due to the direct interactions between electric power and telecommunication lines, etc., causing the earth/ground potential rise, neutral potential rise, and faults in the system. The fault currents may flow directly to telecom lines or through the equipment to the customer's premises, causing adequate damage to the equipment and personnel safety. In wireline applications, analog or digital, central office, exchanges, and subscriber sides have to be protected. Decisive protection and protective methods have to be employed for proper functioning of the equipment under overvoltage/overcurrent conditions. Current investigation reports some interesting results obtained on the recently developed high-voltage high-current protection cards used in digital telecom exchanges. The performances of protection cards both for the ring wave and hybrid wave surges are evaluated and presented. The surge generators required for the investigation are developed and fabricated in house as per the relevant telecom standards.

A Comparative Analysis of Occupational Accidents between Indoor and Outdoor Workers in Telecommunications Industry

Objective: This study aims to analyze the characteristics of occupational accidents and injuries of telecommunications line and cable workers by type of workplace and operational process of cabling service and to provide baseline data in establishing the preventive policies for occupational accidents and injuries. Background: In order to set up the preventive policies for occupational injuries and illness systematically, the accident analysis by industry should be preceded. To establish more effective policies, it should be done by occupation for persons who work in various kinds of occupation rather than by industry for persons who do in the same occupation. Method: In this study, the 176 occupational accidents and injuries were classified by type of workplace - indoor (inside building) and outdoor (at the top of utility pole, in a manhole, or in the fields) - and also done by operational process involved at the time of the accident. By analyzing the characteristics of occupational injuries and illness by type of workplace and operational process, respectively, this study can be helpful in establishing the preventative policies for occupational accidents and injuries. Results: The characteristics of occupational accidents and injuries by type of workplace showed that there were differences in terms of accident rate between indoor and outdoor on age of the injured, while not on employment-size and work experience of the injured. In addition, the characteristics on accident type, agency of accident, parts of body affected, and operational process between indoor and outdoor workplaces were statistically different each other. Conclusion and Application: The findings of occupational accidents’ characteristics can be applied to the establishment of systematic preventative policies for occupational accidents of telecommunications line/equipment workers.

Deregulation of the Nigerian Telecommunication Sector: Interrogating the Nexus Between Imperialism and Development

This study investigates the deregulation of the Nigerian Telecommunication Sector within the precinct of Imperialism and development. This is premised on the fact that Nigeria’s Telecommunication sector has not only been moribund over the years but has more importantly been dominated by foreign and local bourgeoisies after its deregulation in 1999. In view of this, the study borrows from Structural Imperialism which argues that the elites in the Centre and Periphery states connive, indeed conspire to undermine development in the latter. It relies heavily on the use of secondary data, by virtue of the nature of the work, thus probing the dynamics of these Centre/Periphery trajectories. Findings reveal that certain levels of development have been recorded in the Telecommunication sector particularly in terms of contribution to the Nigerian economy through the ubiquitous provision of telecommunication lines, especially the mobile phones. Similarly, jobs have been created within this sector in terms of its contribution to Nigeria’s GDP profile. However, beneath these efforts, the predatory and materialistic character of the foreign and local bourgeoisie, a permanent feature of the post-colonial Nigerian state remains the greatest bane of the growth of this sector. The study concludes that until this “unholy alliance” between the foreign and local bourgeoisies is demolished, the deregulation effort of the federal government will remain a mirage. To this end, it recommends an immediate measure to increase the legislative oversight of the regulatory body, Nigerian Communication Commission (NCC) over the activities of the foreign mobile operators in Nigeria, while not neglecting, indeed promoting the indigenous operators of the telecommunication services in the country. DOI: 10.5901/mjss.2015.v4n1p173

需要家家屋を考慮した配電系統の雷リスク評価

Recently, concept of the lightning risk management has been proposed for the minimization of damages caused by lightning. In distribution systems (power distribution lines, low voltage distribution lines, telecommunication lines and customer appliances), lightning protection measures based on the lightning risk management are effective since the number of facilities is enormous. In this paper, for the establishment of lightning risk management method of distribution systems, we expressed the lightning risk assessment method of distribution systems and examined the influence of arrangement of customer house on the lightning risk values of power distribution lines and customer appliances.

CRITERIA AND ALGORITHMS FOR SHAPING OF THE SIGNAL-CODE SEQUENCES ON THE BASIS OF WI-FI TECHNOLOGY AT DEPLOYMENT OF THE TERAHERTZ BAND TELECOMMUNICATION SYSTEM

The principles of a signal-code sequence shaping are considered, the means and new technologies for selection of the type of the signal sequence are suggested in order to attain the best throughput and efficiency parameters in the telecommunication channel of a wireless data transmission system where the performance is determined by the signal-to-noise ratio at the input of the receiver. Based on the analysis of parameters and criteria recommended by IEEE 802.11а/n specifications for selection of the signal-code sequences, it is suggested the informational efficiency parameter for using the telecommunication channel resources. The telecommunication line was tested to the range of 1.7 km with the help of MikroTik R52n-M wireless interfaces. There were defined the signal-code sequences, which were selected for data transmission by the software-defined radio systems. It was determined that judging upon the signal level at the input of the receiver, types of the signal-code sequence and the obtained data transmission rate, the software-defined radio system using the MikroTik R52n-M equipment is fully compliant with the recommendations provided in IEEE 802.11а/n specifications. Realization of the concept for creation of a Wi-Fi-based software-defined radio systems is demonstrated on the example of a developed gigabit data transmission system in the 130...134 GHz bandwidth of the terahertz band. The system was tested in vitro where it attained the data transmission rate of up to 1.2 Gbps. It is demonstrated that the above data transmission system can be potentially used in transportation and distribution networks for the next generation mobile communication networks providing for the required bitrate, reliability and protection.

Principles of Data Transmission Network Development in the Medium Wave Range in the Waters of the Northern Sea Route

The work shows, that in developing transmission network for data transmission in the waters of the Northern Sea route it is expediently to use medium-wave band at the expense of more steady telecommunication line because of lack of spatial wave in near-field zone. Types of modulation and signal-code designs for down-link and up-link were determined. Also it was established that using amplitude-phase modulations with block turbo code, it provides the best spectral and energy efficiency for down-link and frequency-shift signal for up-link is efficient.

Estimating Demand Function of the Fixed Line Telecommunication in Iran

In the communication age, every country's success depends on telecommunication. In the last years, there has been great changes in telecommunication of Iran, and there has been momentum too. In this paper, demand function of fixed line calls in 30 provinces of Iran in 2012 has been estimated using undated data. In Iran, fixed line calls happen inside cities, inside provinces and between cities. According to Economy Council of Iran, rate of fixed line calls per pulse was fixed from 2004 to 2012. Estimation of demand function of calls between landlines inside a city is meaningless. Nonetheless, in calls between landlines between cities, inside a province and between two provinces, in addition pulse rate, the distance between provinces is essential in estimating expenses. In other words, call rate changes from city to city. In this paper, the effective cost of calls in different cities is calculated, and landline network's demand function is calculated.

Reproducing electric field observations during magnetic storms by means of rigorous 3-D modelling and distortion matrix co-estimation

Electric fields induced in the conducting Earth by geomagnetic disturbances drive currents in power transmission grids, telecommunication lines or buried pipelines, which can cause service disruptions. A key step in the prediction of the hazard to technological systems during magnetic storms is the calculation of the geoelectric field. To address this issue for mid-latitude regions, we revisit a method that involves 3-D modelling of induction processes in a heterogeneous Earth and the construction of a magnetospheric source model described by low-degree spherical harmonics from observatory magnetic data. The actual electric field, however, is known to be perturbed by galvanic effects, arising from very local near-surface heterogeneities or topography, which cannot be included in the model. Galvanic effects are commonly accounted for with a real-valued time-independent distortion matrix, which linearly relates measured and modelled electric fields. Using data of six magnetic storms that occurred between 2000 and 2003, we estimate distortion matrices for observatory sites onshore and on the ocean bottom. Reliable estimates are obtained, and the modellings are found to explain up to 90% of the measurements. We further find that 3-D modelling is crucial for a correct separation of galvanic and inductive effects and a precise prediction of the shape of electric field time series during magnetic storms. Since the method relies on precomputed responses of a 3-D Earth to geomagnetic disturbances, which can be recycled for each storm, the required computational resources are negligible. Our approach is thus suitable for real-time prediction of geomagnetically induced currents by combining it with reliable forecasts of the source field.

Applications of the FDTD Method to Lightning Electromagnetic Pulse and Surge Simulations

Electromagnetic computation methods (ECMs) have been widely used in analyzing lightning electromagnetic pulses (LEMPs) and lightning-caused surges in various systems. One of the advantages of ECMs, in comparison with circuit simulation methods, is that they allow a self-consistent full-wave solution for both the transient current distribution in a 3-D conductor system and resultant electromagnetic fields, although they are computationally expensive. Among ECMs, the finite-difference time-domain (FDTD) method for solving Maxwell's equations has been most frequently used in LEMP and surge simulations. In this paper, we review applications of the FDTD method to LEMP and surge simulations, including 1) lightning electromagnetic fields at close and far distances, 2) lightning surges on overhead power transmission line conductors and towers, 3) lightning surges on overhead distribution and telecommunication lines, 4) lightning electromagnetic environment in power substations, 5) lightning surges in wind-turbine-generator towers, 6) lightning surges in photovoltaic (PV) arrays, 7) lightning electromagnetic environment in electric vehicles (EVs), 8) lightning electromagnetic environment in airborne vehicles, 9) lightning surges and electromagnetic environment in buildings, and 10) surges on grounding electrodes.

The emission characteristics and interference analysis of Power Line Telecommunication

This paper describes characteristics of PLT emission with experiment in semi-anechoic chamber and suggests the method for aggregating multiple interferences based on probabilistic approach in the situation in which multiple PLT modems are operating in close proximity to the radio receiver. The levels of the conducted and radiated emission and the APD characteristics are presented. And compatibility between PLT and radio receiver is analyzed with suggested method. This will be useful for assessing interference effect in the field of radio communication and electromagnetic compatibility.

A Design Method for the Asymmetric Artificial Network With an Asymmetrical Transformer

Conducted asymmetric disturbances are measured at telecommunication ports of equipment under test using an asymmetric artificial network (AAN). Therefore, theoretical investigations are carried out to characterize an AAN with a mode-impedance matrix, introducing the common-mode and differential-mode impedances. By referring to this matrix, a theoretical design method is developed for the AAN with an asymmetrical transformer to satisfy the requirements for the mode impedances and the longitudinal conversion loss. By using this design method, two different prototype AANs are assembled: one meets the CISPR 22 specifications, and the other is used in power line telecommunication modem tests. A detailed experimental examination of the assembled AANs validates the proposed theoretical design method.

Beteg kapcsolattartási jogáról

Man is a social animal, it is important for colleagues to meet, create a relationship with them, to communicate, ideas, exchanging information. Human relationships are determined by the identity of a specific person, place in society, so it should be a fundamental right for all people in contact with the law. However, in certain life situations exercising these rights is necessarily limited, undermined, need frameworks. One of those situations in life with participation in health care in which the patient has to adapt in health care provider operating schedule, however, the Trustee is required to ensure the exercise of the right contacts.
 The most prominent of patients' rights to human dignity, which is inferred from a mother right, from which a number of other important rights. One of these is the right to self-determination, which guarantees freedom of action of the human as an individual incapacity depending autonomous. For patient care recipients should be subject to the fundamental distinction that whether it is inpatient or outpatient care. In the latter case, it also suffers from significant limitations on the patient's right to self-determination , including personal freedom, opportunities for contact with other people. The right to self-determination in a specific part of the realization of rights is thus involved in the regulation of the contact, as during inpatient care plays an important role.
 In today's modern society, the means of communication, networks of past explosive development, get more involved in the exercise of the right to life, human relations than before, with the elimination of the technical obstacles the spatial and temporal obstacles easily can be prevented. Life situation of the theme chosen exercise of the right of communication is of particular importance, because the patient's recovery depends not only on only physical but also mental condition, recovery can define what social relations, quality, intensity. The correspondence law of the health care law more the privileges include such other persons entitled to take the patient's inpatient sanitation place either in writing or orally to maintain contact, to receive visitors, the people he set out to exclude the visit , prohibit the fact of his treatment or the other information related to medical treatment reveals other.
 The context of the law of correspondence can be said that relatively little addressed by legislators and by expanding the scope of the practice of law in the content, but would consider appropriate where more attention is added. It would be good detailed arrangements for the exercise of creating the right framework for the so - to clarify the scope of everyday objects, to establish rules for their use of health services that are appropriate for the task to allow the exercise of these rights - the first line telecommunications.

A mobile robot to be applied in high-voltage power lines

Many theoretical and experimental studies have been carried out in order to develop autonomous robots to travel along telecommunication lines and power transmission lines to perform inspection and/or repair work. These robots can improve the efficiency, reduce labor and are expected to reduce the risks of accident of maintenance personnel. In spite of theoretical researches and technological developments of robotic systems, problems related to stability, controllability, ability to transpose/surmounting obstacles and autonomy still exist. Thus, this paper presents a mobile robot that moves suspended on electric power lines which can surmount different types of obstacles, placed at any position on cable. Firstly is presented a review of some existing robots. After, the kinematics model of the mobile robot and a methodology for spherical obstacle surmounting are presented. Finally, numerical and experimental results are presented to validate the proposed model.

Analysis of Induced Voltage on Telecommunication Line in Parallel Distribution System

A current flowing through a distribution conductor produces induced voltage, which is harmful to a telecommunication line. Previous research on induced voltage has been focused on single- circuit lines in the distribution system. However, the double-circuit lines, referred to as parallel distribution lines, are widely used in distribution systems because they have significant economic and environmental advantages over single-circuit lines. Therefore, a study on the induced voltage in double-circuit lines is needed. This paper presents a method of calculating the induced voltage in a parallel distribution system using four-terminal parameters and vector analysis. The calculation method is verified by the Electromagnetic Transient Program (EMTP) simulation.

Impact of sanctions on procurement of medicine and medical devices in Iran; a technical response.

Following recent sanctions on foreign trade, financial and banking services, Iran has faced major difficulties for importing medicines (both finished products and pharmaceutical raw materials) and medical devices. Problems with money transfer have made it extremely lengthy in time to import medicine and medical devices and these have negatively affected access to and affordability of medicines. Quality of pharmaceuticals and treatment of patients have also been affected due to changing the sources of imported medicines and raw materials for locally produced pharmaceuticals. Several interventions have been employed during the past few months in Iran to overcome the effects imposed by recent sanctions and drug shortages have been managed to some extent with attempts made by Iran Food and Drug Organization (IRI FDO). As recommended by the experts, a specific Society for Worldwide Interbank Financial Telecommunication line should be allocated for transferring money for medicines and medical devices and certain financial institutions are assigned for this purpose. It is also suggested that defining a white list of Iranian pharmaceuticals and medical device companies together with their foreign counterparts would facilitate this process. It appears that, in a public health prospective, ordinary people and patients are hurt and paying the cost for current sanctions. It remains the responsibility of the public health and international communities to separate public health from politics and to ease the pain of public from sanctions.

DFIG 풍력발전기가 연계된 배전선로의 고조파 공진 특성에 관한 연구

There were telecommunication noise and malfunctions of the electronic devices occurred over a wide area due to the high harmonic voltage and/or current levels of the Back-to-back converter in the DFIG wind power system even though the magnitude of all harmonics is within the international standards. The triangular carrier signals of the PWM used in the power converter system is related to the telecommunication noise because they are in the range of audible frequencies and amplified by a variety of the standing waves that were excited by harmonic voltage sources in the weak grid system such as a long distance distribution transmission lines. This paper describes the characteristics of the harmonics in the wind turbine-generator, numerical analysis and simulation of the harmonics resonance phenomena in the distribution lines as well as measuring induced voltage of the telecommunication lines in parallel with power lines in order to verify the root cause of the telecommunication noise. These noise problems can occur in a wind turbine power system with a non-linear converter at any time, as well as photovoltaic power system. So, the preliminary review of suitable filter devices and switching frequencies of the PWM have to be required by considering the stability of the controller at the design stage but as part of the measures the effect of the telecommunication cable shields was analyzed by comparing the measured data between multi-conductor with/without shields so as to attenuate the sources of the harmonics voltage induced into the telecommunication lines and to apply the most cost-effective measures in the field.

Electromagnetic Interference between Power/ Telecommunication Lines and Railway Systems

Electromagnetic Interference between Power/ Telecommunication Lines and Railway Systems