- Tanzania, United Republic of
Nerey Mvungi
University of Dar es Salaam, Computer Science and Engineering, Faculty Member
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This paper presents the influencing of load impedance, line length and branches on the performance of medium voltage power line communication (PLC) network. The power line network topology adopted here is similar to that of the system in... more
This paper presents the influencing of load impedance, line length and branches on the performance of medium voltage power line communication (PLC) network. The power line network topology adopted here is similar to that of the system in Tanzania. Different investigation with regard to network load impedances, direct line length (from transmitter to receiver), branched line length and number of branches has been investigated. From the frequency response of the transfer function (ratio of the received and transmitted signal), it is seen that position of notches and peaks in the magnitude responses are largely affected in terms of attenuation and dispersion by the above said network parameters/configuration. The observations presented in the paper could be helpful in suitable design of the PLC systems for a better data transfer and system performance.
Research Interests:
Research Interests:
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This paper presents the influencing of load impedance, line length and branches on the performance of medium voltage power line communication (PLC) network. The power line network topology adopted here is similar to that of the system in... more
This paper presents the influencing of load impedance, line length and branches on the performance of medium voltage power line communication (PLC) network. The power line network topology adopted here is similar to that of the system in Tanzania. Different investigation with regard to network load impedances, direct line length (from transmitter to receiver), branched line length and number of branches has been investigated. From the frequency response of the transfer function (ratio of the received and transmitted signal), it is seen that position of notches and peaks in the magnitude responses are largely affected in terms of attenuation and dispersion by the above said network parameters/configuration. The observations presented in the paper could be helpful in suitable design of the PLC systems for a better data transfer and system performance.
Research Interests:
Research Interests:
This paper presents the influencing of load impedance, line length and branches on the performance of medium voltage power line communication (PLC) network. The power line network topology adopted here is similar to that of the system in... more
This paper presents the influencing of load impedance, line length and branches on the performance of medium voltage power line communication (PLC) network. The power line network topology adopted here is similar to that of the system in Tanzania. Different investigation with regard to network load impedances, direct line length (from transmitter to receiver), branched line length and number of branches has been investigated. From the frequency response of the transfer function (ratio of the received and transmitted signal), it is seen that position of notches and peaks in the magnitude responses are largely affected in terms of attenuation and dispersion by the above said network parameters/configuration. The observations presented in the paper could be helpful in suitable design of the PLC systems for a better data transfer and system performance.
Research Interests:
Researchers have shown that practical mobile communication channels introduce errors that are concentrated in a certain locality rather than random errors. These are burst errors caused by deep fading of the wireless channel or a... more
Researchers have shown that practical mobile communication channels introduce errors that are concentrated in a certain locality rather than random errors. These are burst errors caused by deep fading of the wireless channel or a lightning strike. The existing Viterbi Algorithm (VA) capable of correcting random errors is inefficient in correcting burst errors and therefore resulting in unacceptable amount of residual errors. This paper presents an assessment of Non- Transmittable Codewords (NTCs) enhancement technique to VA in decoding the received signals subjected to burst errors that may occur in poor channels. A hard decision, 1/2 rate and constraint length K is equal to 3 Viterbi Algorithm decoding technique, Binary Phase- Shift Keying (BPSK) and Additional White Gaussian Noise (AWGN) are components used in MATLAB software based simulation when assessing the proposed technique. Applying 6NTCs to VA decoder enables the decoder to reduce 83.7 percent of its residual errors. However, the technique reduces the encoder’s data transmission rate from 1/2 to 1/6.
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The use of website for wide-ranging applications has become a reality following rapid developments in communications and information technologies. Government and their agencies have adopted and used it to communicate with and to offer... more
The use of website for wide-ranging applications has become a reality following rapid developments in communications and information technologies. Government and their agencies have adopted and used it to communicate with and to offer services to their citizens. The approach of using information technology (IT) is conceived as being easier and more convenient. Therefore, increasingly governments and their agencies use websites to provide information and services. The problem is whether the services and information reach the intended recipients. This paper looks at different schemes to assess the utilization of such offerings, the factors and parameters that influence its acceptability. A conceptual modal to measure acceptability and use of government websites is presented based on six identified parameters: trust, usefulness, easy of use, satisfaction and demographic characteristics.
Nowadays many researchers and international organizations are looking on the availability of getting single communication systems for automation of management of power systems. This paper presents four communication system(s); Power Line... more
Nowadays many researchers and international organizations are looking on the availability of getting single communication systems for automation of management of power systems. This paper presents four communication system(s); Power Line Communication (PLC), Optical Fiber, Satellite Communication and Wireless Communication. PLC and Optical Fiber were selected to be the most effective communication system(s) in automation of management of power systems from generation level to end users level in Tanzania. The criteria used to select PLCs and Optical fiber communication systems are; capacity, coverage, security, reliability, accuracy, and availability. The use of effective communications systems on power networks will help the power utility company Tanzania Electrical Supply Company (TANESCO) to perform actions like reading the electricity meter, monitoring the power consumers, finding faults along the systems, detecting illegal electricity usages etc to ensure better provision of ser...
Road transport takes about 70% of the transportation systems in Tanzania. The number of vehicles and urbanization had been increasing while the road infrastructure capacity remained the same; hence the number of road accidents, casualties... more
Road transport takes about 70% of the transportation systems in Tanzania. The number of vehicles and urbanization had been increasing while the road infrastructure capacity remained the same; hence the number of road accidents, casualties and deaths kept rising. The rate of road accidents has to be reduced. Wireless technologies have shown to be a good candidate for facilitating road safety and transport efficiency through vehicular communications. Hence, it has been an area of active research work. It has been considered to integrate traffic information from traffic unit into cellular networks and to broadcast the information to road users as a means to increase road safety and to optimize road usage. This work tested the use of wireless technologies to support road users using North Chiang Tung University Network Simulator which showed that broadcasting traffic information to road users at a particular point using cellular networks can increase road safety. In this paper causes of...
Digital broadcasting has been an area of active research, development, innovation and business models development in recent years. This paper presents a survey on the characteristics of the digital terrestrial television broadcasting... more
Digital broadcasting has been an area of active research, development, innovation and business models development in recent years. This paper presents a survey on the characteristics of the digital terrestrial television broadcasting (DTTB) standards, and implementation status of DTTB worldwide showing the standards adopted. It is clear that only the developed countries and some in the developing ones shall be able to beat the ITU set analogue to digital broadcasting migration deadline because of the challenges that these countries faces in digitizing their terrestrial broadcasting. The challenges to keep on track the DTTB migration plan are also discussed in this paper. They include financial, technology gap, policies alignment with DTTB technology, etc. The reported performance comparisons for the different standards are also presented. The interesting part is that the results for many comparative studies depends to a large extent on the objective behind such studies, hence counte...
Communication over wireless media is vulnerable to distortion by noise. Therefore, the application of error control mechanism is necessary to minimize the Bit Error Rate (BER). It is proposed to use locked binary convolutional code with... more
Communication over wireless media is vulnerable to distortion by noise. Therefore, the application of error control mechanism is necessary to minimize the Bit Error Rate (BER). It is proposed to use locked binary convolutional code with Non-Transmittable codewords to enhance Viterbi Algorithm decoders; as one of the forward error correction mechanisms. The proposed enhancement empowers Viterbi algorithm decoders to reduce one of its inherent limitations of residual errors due to burst errors. This paper evaluates the performance of the locked (2, 1, 2) binary convolutional code with Non-Transmittable codewords enhancement technique over flat and slow Rayleigh Fading channel using a MATLAB software simulation. Simulation result shows 80.92 percent reduction of residual errors when 6 Non-Transmittable Codewords were applied to Viterbi Algorithm (VA) decoding. On the other hand, the technique lowers the encoder’s data transmission rate from 1/2 to 1/6.
Rural areas of Tanzania are still disadvantaged in terms of diffusion of IP-based services; this is due to lack of Information and Communication Technology (ICT) infrastructures, especially lack of connectivity. One of the limitations for... more
Rural areas of Tanzania are still disadvantaged in terms of diffusion of IP-based services; this is due to lack of Information and Communication Technology (ICT) infrastructures, especially lack of connectivity. One of the limitations for connectivity problems in rural areas of Tanzania is the high cost to establish infrastructures for IP-based services [1-2]. However the cost of connectivity varies from one technology to the other and at the same time, the cost is also different from one operator (service provider) to another within the country. This paper presents development of software system to calculate cost of connectivity to rural areas of Tanzania. The system is developed to make an easy access of connectivity cost from different technologies and different operators. The development of the calculator follows the V-model software development lifecycle. The calculator is used to evaluate the economic viability of different technologies considered as being potential candidates...
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ABSTRACT Power line has been proposed as a solution to deliver broadband services to end users. Various studies in the recent past have reported the decrease in channel capacity with increase in number of branches for a given channel type... more
ABSTRACT Power line has been proposed as a solution to deliver broadband services to end users. Various studies in the recent past have reported the decrease in channel capacity with increase in number of branches for a given channel type (indoor channel or access (low voltage) channel or medium channel). Those studies however did not provide a clear insight as to how the channel capacity is related to the number of distributed branches along the line. This paper attempts to quantify and characterize the effects of channel capacity in relation to number of branches and also with different terminal loads for a given type of channel. It is shown that for power spectral density (PSD) between -90dBm/Hz to -30dBm/Hz, the channel capacity decreases by 20-30Mbps/branch, 14-24Mbps/branch and 20- 25Mbps/branch for medium voltage channel, low voltage channel and indoor channel respectively. In additional, it is shown that the channel capacity is minimum when the load impedance is terminated in characteristic impedances for any type of channel treated here. It is shown that there could be significant loss in channel capacity if a ground return were used instead of adjacent conductor return. The analysis presented in the paper would help in designing appropriate power line communication equipment for better and efficient data transfer.
... Anatory and Nerey .H. Mvungi Department of Computer and Systems Engineering Faculty of Electrical and Computer Systems Engineering University of Dar es salaam, PO ... From HT pole the cable is 50mmz, 20m long, AACSR to secondary... more
... Anatory and Nerey .H. Mvungi Department of Computer and Systems Engineering Faculty of Electrical and Computer Systems Engineering University of Dar es salaam, PO ... From HT pole the cable is 50mmz, 20m long, AACSR to secondary substation (distribution transformer). ...
ABSTRACT Power utility companies have suffered revenue losses due to uncollected bills and energy tampering for many years. The use of remote monitoring system to overcome the problem using powerline communication has been identified as a... more
ABSTRACT Power utility companies have suffered revenue losses due to uncollected bills and energy tampering for many years. The use of remote monitoring system to overcome the problem using powerline communication has been identified as a solution. This needs tampering detection and transceiver capable of communicating data through powerline channel. We have identify different kinds of tampering and present simulated results of tampering detection and BPSK (DSSS) transceiver design for energy metering as a solution to the problem. The choice of spread spectrum BPSK modulation scheme is based on its robustness and its ability to spread signal into wide band to protect jamming and interference. The performance of the designed tampering detection, transceiver and selection of suitable parameter is verified using Matlab simulation.
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Abstract The paper presents the effects of branches on powerline networks performance using recent developed model. The channels segments which have been compared are access, indoor and medium voltage channels. The comparison was done by... more
Abstract The paper presents the effects of branches on powerline networks performance using recent developed model. The channels segments which have been compared are access, indoor and medium voltage channels. The comparison was done by varying ...
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Recently it has been identified that powerline network is the promise cost effective for broadband accessibility compared to competitors technology. Since, powerline channel has been designed to provide electricity, using it for broadband... more
Recently it has been identified that powerline network is the promise cost effective for broadband accessibility compared to competitors technology. Since, powerline channel has been designed to provide electricity, using it for broadband communication various issues have to be addressed. These include channel characterization, noise, modulation to be used, coding etc. The topology of powerline network affects the transfer characteristics of the channel. In this paper, the powerline channel problems have been modeled for utilization by broadband access. In addition different techniques such as application of modulation, and coding have been addressed and the simulation results have been discussed.
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ABSTRACT This paper looks into prospects of pre-timed arterial traffic control systems for cities with limited infrastructures. The methodologies for designing a pre-timed arterial traffic controller system were researched. A prototype... more
ABSTRACT This paper looks into prospects of pre-timed arterial traffic control systems for cities with limited infrastructures. The methodologies for designing a pre-timed arterial traffic controller system were researched. A prototype designed and implemented in field programmable gate arrays (FPGA) is presented. Dar es Salaam Roads have been used to provide data for the design and implementation whereby the neighboring road intersections within a logically computed radius of less than 250 m qualified for pre-timed arterial traffic controller. One intersection is a master and the remaining ones act as slaves. Using Very High Speed hardware descriptive language (VHDL), an algorithm has been developed for coordinating adjacent traffic signals along the arterial roads. The use of VHDL enabled the algorithm to be implemented and tested in Xilinx Spartan 2E field programmable gate array (FPGA) that functioned and served the purpose of real-time simulation of arterial traffic controller.
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... Such attacks were fairly common in late 1996 and early 1997, but are now becoming less popular. ... [8] Mark Handley and Vern Paxson, Network Intrusion Detection: Evasion, Traffic ... [11] LaMacchia et al NET Framework Security,.... more
... Such attacks were fairly common in late 1996 and early 1997, but are now becoming less popular. ... [8] Mark Handley and Vern Paxson, Network Intrusion Detection: Evasion, Traffic ... [11] LaMacchia et al NET Framework Security,. published by Pearson Education, 2002. ...
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ABSTRACT The paper presents the mathematical modeling and simulation of communication tower grounding system during lightning strike under MATLAB/SIMLINK environment. The transmission line model is used to simulate both the tower and the... more
ABSTRACT The paper presents the mathematical modeling and simulation of communication tower grounding system during lightning strike under MATLAB/SIMLINK environment. The transmission line model is used to simulate both the tower and the grounding system. Different methods of grounding such as vertical rod, horizontal rectangular grounding and the combination of the two are studied under lightning condition. Different conditions of the soil and the effect of soil resistivity are considered and compared. The result is voltage, current and impedance variations at the point of discharge and other selected points.
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ABSTRACT Rural areas of the developing countries lack Information and Communication Technology (ICT) infrastructures such as access network, also known as last mile connectivity, to deliver ICT services. The lack of connectivity is due to... more
ABSTRACT Rural areas of the developing countries lack Information and Communication Technology (ICT) infrastructures such as access network, also known as last mile connectivity, to deliver ICT services. The lack of connectivity is due to high cost of implementing ICT infrastructures. Wireless technologies are envisioned as candidates for rural connectivity. They are not only easier and faster to deploy but also cheaper than the wired technologies. This paper presents a techno-economic analysis of two wireless technologies in Tanzania, called third generation (3G) implemented at 900MHz and at 2100MHz frequency bands. Objectives of techno-economic analysis are to investigate economic feasibility and to determine a cost effective option between the two connectivity options. Results show that, 3G at 900HMz is a feasible and cost - effective connectivity technology in Tanzania. These results can be generalized to other developing countries, since rural areas pose similar characteristics with regard to ICT infrastructure development.
The extensive use of computers and networks for exchange of information has also had ramifications on the growth and spread of crime through their use. Law enforcement agencies need to keep up with the emerging trends in these areas for... more
The extensive use of computers and networks for exchange of information has also had ramifications on the growth and spread of crime through their use. Law enforcement agencies need to keep up with the emerging trends in these areas for crime detection and ...
... Vol. 47, No. 2, pp. 160-167, 2009. [3] AHMR Islam, RA Shafik, MI Hassan and JB Song. "Next Generation Rural Wireless Connectivity Model for Developing Countries," Proceedings of 12th IEEE Asia Pacific Conference on... more
... Vol. 47, No. 2, pp. 160-167, 2009. [3] AHMR Islam, RA Shafik, MI Hassan and JB Song. "Next Generation Rural Wireless Connectivity Model for Developing Countries," Proceedings of 12th IEEE Asia Pacific Conference on Communications (APCC2006), Busan, Korea. 2006. ...
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Abstract An underground cable power transmission system is widely used in urban low-voltage power distribution systems. In order to assess the performance of such distribution systems as a low-voltage broadband power-line communication... more
Abstract An underground cable power transmission system is widely used in urban low-voltage power distribution systems. In order to assess the performance of such distribution systems as a low-voltage broadband power-line communication (BPLC) channel, this ...
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... A practical example has already shown by ICT for Rural Development (ICT4RD) project that succeeded to provide ICT access opportunity between Bunda and Mugumu (figure 5) through an optic fiber cable installed by the Tanzanian Electric... more
... A practical example has already shown by ICT for Rural Development (ICT4RD) project that succeeded to provide ICT access opportunity between Bunda and Mugumu (figure 5) through an optic fiber cable installed by the Tanzanian Electric Supply Company (TANESCO). ...
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... Justinian Anatory, Student Member, IEEE, Nelson Theethayi, Member, IEEE, Mussa M. Kissaka,Nerey H. Mvungi, and Rajeev Thottappillil, Senior Member, IEEE ... the link between points A and J. The distance between points A and J was 4... more
... Justinian Anatory, Student Member, IEEE, Nelson Theethayi, Member, IEEE, Mussa M. Kissaka,Nerey H. Mvungi, and Rajeev Thottappillil, Senior Member, IEEE ... the link between points A and J. The distance between points A and J was 4 km, while all branches were 30 m long. ...
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This paper presents the effects of load impedance, line length and branches on the performance of an indoor voltage broadband power line communications (BPLC) network. The power line network topology adopted here is similar to that of the... more
This paper presents the effects of load impedance, line length and branches on the performance of an indoor voltage broadband power line communications (BPLC) network. The power line network topology adopted here is similar to that of the system found in Tanzania. Different investigations with regard to network load impedances, direct line length from transmitter to receiver, branched line length,
Research Interests: Smart Grid and PLC
... and Nerey H. Mvungi ... Assuming interleaving between the Viterbi decoder and the Reed-Solomon decoder is sufficiently long, to break up long bursts of errors out of the Viterbi decoder, the Reed Solomon symbol error probability ( )... more
... and Nerey H. Mvungi ... Assuming interleaving between the Viterbi decoder and the Reed-Solomon decoder is sufficiently long, to break up long bursts of errors out of the Viterbi decoder, the Reed Solomon symbol error probability ( ) for symbols in can be upper bounded by the ...
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ABSTRACT Estimation of electromagnetic (EM)-fleld emissions from broadband power-line communication systems (BPLC) is necessary, because at its operating frequencies, the radiated emissions from BPLC systems act as sources of... more
ABSTRACT Estimation of electromagnetic (EM)-fleld emissions from broadband power-line communication systems (BPLC) is necessary, because at its operating frequencies, the radiated emissions from BPLC systems act as sources of interference/crosstalk to other radio-communication systems. Currently, the transmission-line (TL) system used for BPLC is complex, involving arbitrarily/irregularly distributed branched networks, arbitrary termination loads, varying line lengths, and line characteristic impedance. In order to study the electromagnetic-compatibility (EMC) issues associated with the radiated emissions of such complex BPLC networks, knowledge of current and voltage distributions along the length of the power-line channels is needed. This paper attempts to derive and present generalized expressions for either the current or voltage distribution along the line (whose TL parameters are known) between the transmitting and receiving ends for any line boundary condition and configuration based on the TL theory. The expressions presented in this paper could be beneficial for direct calculation of EM emissions from BPLC systems.
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... Justinian Anatory, Student Member, IEEE, Nelson Theethayi, Member, IEEE, Rajeev Thottappillil, Senior Member, IEEE, Mussa M. Kissaka, and Nerey H. Mvungi ... A and J was 4 km, 1.2 km, and 20 m, while all corresponding branch lengths... more
... Justinian Anatory, Student Member, IEEE, Nelson Theethayi, Member, IEEE, Rajeev Thottappillil, Senior Member, IEEE, Mussa M. Kissaka, and Nerey H. Mvungi ... A and J was 4 km, 1.2 km, and 20 m, while all corresponding branch lengths were 30, 20, and 10 m long for the MV ...
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... Justinian Anatory, Member, IEEE, Nelson Theethayi, Member, IEEE, Rajeev Thottappillil, Senior Member, IEEE, Mussa Kissaka, and Nerey Mvungi ... 10. The length from ac is 1.2 km with all branches 20 m long concentrated at node B. All... more
... Justinian Anatory, Member, IEEE, Nelson Theethayi, Member, IEEE, Rajeev Thottappillil, Senior Member, IEEE, Mussa Kissaka, and Nerey Mvungi ... 10. The length from ac is 1.2 km with all branches 20 m long concentrated at node B. All terminal loads were 50 . ...