Browsing by Author "Amin Babiker A/Nabi Mustafa"

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DeIay Controlin Multi-Class Multi –Server RST- based Communication Networks ViaM/K Setting
(جامعة النيلين - كلية الدراسات العليا, 2017-01-16) Amin Babiker A/Nabi Mustafa; Muawia Mohammed Ahmed Mahmoud; Ismail El-Azhary T.; Huda Adibah Mohd Ramli
Abstract In the present work, analysis of non-preemptive priority queues with multiple servers and multiple priority classes, which is based on Residual Service Time (RST) was utilized to calculate the total waiting time for system customers. Deﬁnitely, this waiting time is determined by several parameters such as the number of servers, the order of the Priority class to which the customer belongs and the total number of customers in the system.Analysis of the results showed that different Priority class order/Number of Servers combinations could attain the same waiting time. Accordingly, these parameters could be used in determining the desired level of performance expressed in terms of waiting time. The obtained results of waiting times and their relations with priority class orders and Number of Servers could help a lot in justifying and supporting this proposed RST-Based Analysis. Keywords Non-preemptive priority queues, residual service time, total waiting time, RST-based analysis.
RESIDUAL SERVICE TIME BASED ANALYSIS OF MULTI-CLASS MULTI-SERVER PRIORITY . QUEUING SYSTEMS
(Neelain University, 2007) Amin Babiker A/Nabi Mustafa
ABSTRACT In this research, Multi-Class Multi-Server Priority Queuing Systems. service times for all priority classes are assumed to be identically and exponentially distributed. This assumption led to the possibility of extending the analysis of non- preemptive priority queuing systems to the multiple servers case (similarly to multiple communication channels). ' The extension is based on the developed fomiula for the residual service time R. This on its part, was achieved by utilizing the analysis of M/M/m systems in which the service times are identically and exponentially distributed, combining this with the analysis of non-preemptive queuing systems for single server systems based on M/G/l system. Making all necessary modiﬁcations for the system to ﬁt the multiple servers case, the necessary mathematical analysis and derivations were given. The Preemptive Priority queues with Multiple Servers and Multiple priority classes were treated in the same manner. Here the assumption that the service times - for all priority classes — are identically and exponentially distributed _is put forward. Again, a formula for the residual service time is developed and utilized in calculating the average customer waiting time and other related parameters. In the light of this assumption the author presents the relations necessary to derive an expression for the mean residual service time which is then used in developing a mathematical model for the analysis of preemptive priority queues with multiple servers and multiple priority classes. The research includes some comparative studies between the proposed model (multi-class multi-servers priority queuing systems) and some prior related works.
Studying Mobile Ad-Hoc Network protocols using OPNET
(جامعة النيلين - كلية الدراسات العليا, 2017-01-16) Amin Babiker A/Nabi Mustafa; Rana Abdelrahman Osman Mohamed
Abstract Ad Hoc network is wireless nodes directly communicate with each other without any access point or base station, each node take part to transmit the packet to the destination. Ad Hoc network can be mobile node (MANET) or ﬁxed node (FANET). DSR, AODV and TORA are three different MANET routing protocols. The present study practically afford a comparison between these three protocols in order to analyze their perfomance using OPNET simulator to achieve this experience, this after giving an over view of those three protocols.
Uplink and downlink in LTE
(جامعة النيلين - كلية الدراسات العليا, 2017-01-16) Marola Yousri Yousif Masood; Amin Babiker A/Nabi Mustafa
Abstract The aim of this study is to evaluate and analyzeCoverage by quality indicator , Coverage by throughput , Coverage by c/(I+N) level and Effective signal analysis in uplink and downlink of LTE (long term evaluation). LTE is the next major step in mobile radio communications, and was introduced in 3GPP Release 8, the target in 3GPP Release 8 is to improve the network scalability for trafﬁc increase and to minimize the end-to-end latency by reducing the number of network elements. LTE uses orthogonal frequency division multiplexing (OFDM) as its radio access technology in downlink and uplink multiple access the Single Carn'erFrequency Division Multiple Access (SC-FDMA), together with advanced antenna technologies. The major difference between the OFDMA signal for downlink and the SC-FDMA signal for uplink is that it uses a discrete Fourier transform function on the data to convert it into a fonn that can be used to transmit. Discrete Fourier transform functions are oﬁen used to convert digital data into analog waveforms for decoding audio and video and it can be used for outputting the proper radio frequencies too. Keywords:LTE, OFDM, SC-FDMA, downlink, uplink.