ZigBee Wireless Technology is the leading global standard for implementing low-cost, Low-data-rate, short-range wireless networks with extended battery life. The ZigBee standard provides network, security, and application support services operating on top of the IEEE 802.15.4 Medium Access Control (MAC) and Physical Layer (PHY) wireless standard. It employs a suite of technologies to enable scalable, self-organizing, and self-healing networks that can manage various data traffic patterns, The low cost allows the technology to be widely deployed in wireless control and monitoring applications, the low power-usage allows longer life with smaller batteries, and the mesh networking provides high reliability and larger range. ZigBee has been developed to meet the growing demand for capable wireless networking between numerous low power devices. In this paper , we will try to give a complete picture about ZigBee technology including the structure of this technology, the layers where this technology works referred to the OSI model, how this technology works, the main components that use to create a ZigBee network, The objective of this simulation is to establish tree topology networkby; using an OPNET Modeller 14.5 program, and to investigate the performance of the network model, and see the effect on data when we change the time of transmission and finally we will investigate the performance of some network models that employ IEEE 802.15.4 protocol using different scenarios. arabic 19 English 91
Mariam Abojela Msaad, Almoatasem Aboaisha , Ahmed Eshoul(12-2019)

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)

This paper describes a proposal for FAT tree based Network-on- Chip system based on MPLS forwarding mechanism. The FAT tree includes processing nodes and communication switches. IP node (processing nodes) has a message generator unit which randomly generates messages to different destinations with different packet lengths and buffering. The switch is based on MPLS technique and consists of the following units: crossbar switch, input/output link controllers and routing and arbitration units. A simulator has been developed in C++ to analyze the proposed architecture. A comparison with wormhole switch is provided to show the efficiency of the MPLS designed switch arabic 12 English 65
Azeddien M. Sllame, Nagwa Abobaker Salama(1-2016)