In this paper a brief introduction to the concept of quality of service has been given. However, it mainly focuses on the classification of routing algorithms based on a number of different criteria like: protocols, structure, technologies in use, etc. And it concludes with a presentation of a common problem facing routing protocols, namely routing loops, and explained the known solutions to that problem. arabic 6 English 52
Ibrahim Almerhag, Ali Ganoun(6-2018)

Abstract In wireless communication systems the data rate, capacity, coverage, and spectral efficiency; can be enhanced with multi-carrier transmission and multi-antenna, then the overall wireless communication system performance is greatly enhanced by combining OFDM and MIMO schemes, MIMO helps in increasing the throughput where as OFDM spreading out the frequency selective fading channel over many symbols. In this thesis evaluating performance of the system depends on both link and system levels, where the measure of performance is represented in the throughput, cell radius and the effective signal to interference plus noise ratio (SINR). It also depends on the employed capacity criterion and it takes into account the impact of adaptive modulation and coding. the worked scenarios start from a link level extending to a system level in 3GPP LTE. To achieve the above a number of tasks followed by observations are carried out. They start by analysis of the equations and a Matlab program is written to calculate the cell edge throughput, cell coverage and DL capacity. After the programs implementation, the multi antenna transmission effect is noted on the arrival throughput when taking into account the modulation technique. When increasing the order of the antenna and the throughput is also increased, but it must be traded off with the probability of error; Coverage has also improved by decreasing the order of the modulation technique. For the system level with different traffic, the overall throughput of the system and the capacity of the network are determined by the number of resource blocks (RBs). These RBs depend on the bit rate of the service and bit rate for each RB. The adopted scenarios in this thesis start from link to system, where the features are represented in a flexible base station and user configurations, channel modeling with path loss, user mobility, also at different transmitter and receiver (MIMO). The approaches are useful in single user and multi-user MIMO, then all of the above can be standardized by metrics: capacity, throughput, spectral efficiency, user QoS etc. Finally thesis conclusion and some future work as an extension of this work are presented.
احمد محمد التانزفتى (2013)

Abstract In order to ensure the promise of anytime-anywhere communication to the customers, Mobile operators must be able to support a large number of users over a large coverage area. So Coverage and Capacity are important issues in the planning process for Third Generation (3G) mobile networks. The planning process aims to allow the maximum number of users sending and receiving adequate signal strength in a cell. In Code division multiple access (CDMA), the Coverage and capacity are not independent of each other as in GSM, it is interference-limited system, meaning that if the traffic increases, the serving cell radius decreases, hence the term cell breathing occurs. This work studies the capacity and coverage of a macrocell CDMA network. The cell breathing effect is studied and a new criteria to link Capacity and Coverage is developed, it is named by Capacity-Coverage Product; CCP. Different designations of CCP formula are given. The influencing of various system parameters on this CCP are studied. Knowing this CCP, the capacity and coverage become straight to estimate. The user distribution is very important issue. Most of previous studies treat user distribution as uniform. This thesis considers the case of non uniform user distributions where a more realistic distribution is chosen. A new interference distribution factor is initiated. The impact of this factor on the capacity and coverage is studied. Existing of Hotspot regions of traffic will cause coverage shrinkage. Installation of hotspot microcells BS inside existing macrocell BS is one possible solution to such situations. In this work a microcell is introduced within the macrocell and a new system parameters are obtained such that the coverage and performance are maintained while the capacity is increased.
محمد عبدالرزاق العالم (2007)