Abstract Voice over IP (VoIP) uses the Internet Protocol (IP) to transmit voice as packets over an IP network, like the Internet, Intranets and Local Area Networks (LAN). Here the voice signal is digitized, compressed and converted to IP packets and then transmitted over the IP network. However, at the receiving end, some packets may be missed in its way due to network congestion. This packets loss degrades the quality of speech at the receiving end of a voice transmission system in the IP network. Since the voice transmission is a real time process, the receiver cannot request for retransmission of the missing packets. High speed networks provide real time variable bit rate service with packet loss requirements. The burstiness of the correlated traffic makes dynamic buffer management highly desirable to satisfy the Quality of Service (QoS) requirements. This thesis presents an algorithm to improve and optimize the Adaptive Buffer Allocation Scheme to deal with input traffic based on loss of consecutive packets in data streams and buffer occupancy levels. Buffer is designed to allow the input traffic to be partitioned into different priority classes, and based on the input traffic behavior it controls the threshold dynamically. This scheme allows input packets to enter into buffer if its occupancy level is less than the threshold value for priority of that packet. The threshold is dynamically varied in runtime based on packet loss behavior. The performance evaluation is carried out using simulation and is carried out for two and multiple priority classes of the input traffic "real time and non real time classes". The simulation results show that the Modified Adaptive Partial Buffer Sharing (ADPBS) has better performance than Adaptive Partial Buffer Sharing under the same traffic conditions.
اسماء احمد الكيش (2010)

Free space optical (FSO) communication is a promising solution to deliver the last mile communication and to guarantee a high data rate. However, the performance of FSO links can be significantly degraded by adverse weather conditions. Recently, machine learning algorithms (MLAs) have emerged for robust prediction to optimize the network performance. In this work, the Quality factor (Q) of FSO systems is estimated by means of four MLA models, namely, multi-linear regression, support vector regression, decision tree regression, and random forest regression. The synthetic data is used for training and testing these MLAs models, and several atmosphere conditions are considered with multiple transceivers FSO link system. The results of decision tree and random forest models demonstrated high coefficient of determination (R 2 ) and low mean square error (MSE) as compared to the other models.
Amal A. Algedir, Taissir Y. Elganimi(10-2020)

Abstract The number of mobile service users has been tremendously increased during the last few years, and the types of mobile services are developed from pure voice to data and multimedia services, such as audio/video streaming, e-mail, file transfer, and web browsing. These services have quite different requirements for their quality. 3G WCDMA cellular mobile networks answer this growing demand for these wireless data services. Then it needs to provide a huge capacity and wide area of coverage with acceptable quality of service. Capacity and coverage in WCDMA networks planning are the important issues because they are dependent of each other and related to the services data rate. In this thesis the capacity and coverage of mixed rate services are derived and analyzed. The uplink Capacity Coverage Product (CCP) of mixed rate services is developed by two methods, and three scenarios are assumed. The first method is the exact solution and the second method is the approximate solution. Math lap computer programs are used to get results and curves. Then some parameters affecting the mixed rate CCP are studied and a comparison between the two methods is also performed.The application of CCP in dimensioning and planning of a single service and mixed rate services WCDMA network is presented. A comparison with the conventional planning method is performed.
علي صالح منصور (2008)