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)

Successful companies know that network management is crucial for the proper support and maintenance of network infrastructure. When it comes to managing a large-scale or highly complex network, you’ll need a powerful network management system that will meet your challenging business needs. There are several programs suggested different types of solutions. PRTG and SolarWinds are an excellent solution, since they have many features that help the network engineer, administrator or technician to easily control, manage and monitor the devices comprehensively. Moreover, PRTG and SolarWinds can integrate with monitoring and management protocols such as SNMP and NetFlow to provide an excellent integrated unified management solution. That being said, PRTG and SolarWinds will facilitate the management of network devices throughout performing configuration, Security, Fault, Performance and Accounting management which will increase productivity, Quality, Revenue and lower the cost. arabic 9 English 66
Mariam Abojela Msaad, Mohamed Fathi Almograbi , Anas Moftah Alshoukri (12-2019)

Abstract: In WiMAX networks, the biggest challenge is to overcome the effects of fading especially when nodes are mobile. The multipath nature of channel leads to ISI (Inter Symbol Interference) and the severity of ISI effects increases with bandwidth increase and this might get worse when nodes are moving . The radio link between the Base Station and Service Station/Mobile Station can be a LOS or it can be a NLOS. The environmental objects and features like buildings, weather conditions can severely obstruct NLOS signal. In this paper the effect of pedestrian multipath and node mobility in WiMAX network is studied under different codecs schemes in order to evaluate the effect of multipath channel fading when nodes are moving on the QoS parameters end to end delay, jitter, mean opinion score and throughput of a VoIP application. The obtained results showed that multipath fading with mobile nodes has sever effect on throughput and MOS value for all studied codecs and on the other parameters the effect varies depending on the implemented codecs. arabic 14 English 71
N. Aboalgasm, I. Almerhag , A. Daeri(3-2018)