Worldwide interoperability microwave access (WiMAX) is an 802.16 wireless standard that delivers high speed, provides a data rate of 100 Mbps and a coverage area of 50 km. Voice over internet protocol (VoIP) is flexible and offers low-cost telephony for clients over IP. However, there are still many challenges that must be addressed to provide a stable and good quality voice connection over the internet. The performance of various parameters such as multipath channel model and bandwidth over the Star trajectoryWiMAX network were evaluated under a scenario consisting of four cells. Each cell contains one mobile and one base station. Network performance metrics such as throughput and MOS were used to evaluate the best performance of VoIP codecs. Performance was analyzed via OPNET program14.5. The result use of multipath channel model (disable) was better than using the model (ITU pedestrian A). The value of the throughput at 15 dB was approximately 1600 packet/sec, and at -1 dB was its value 1300 packet/se. According to data, the Multipath channel model of the disable type the value of the MOS was better than the ITU Pedestrian A type.

In this paper, the semiconductor optical amplifier (SOA) is used with a Mach-Zehnder interferometer (MZI) forming an SOA-MZI structure which is used to perform the logic gates OR, and NOT. It is simulated at 10 Gbps, 20 Gbps, and 40 Gbps to extract simple design rules. Two binary input data signals are simulated at several bitrate 10 Gbps, 20 Gbps, and 40 Gbps. It is demonstrated that high data rate can be achieved with a specific injection current in SOA. SOAs required low injection current, which leads to a low value on the total power consumption of the gate. In addition, this work includes the study of the effect of the bit rate on the received power, minimum bit error rate (BER), and maximum quality factor (Q-factor). The logical output of the gate has an extinction ratio of more than 10 dB with good eye opening. The output of the OR, NOT gates shows error-free operation at different bit rate with a clear eye opening. General TermsOptical amplifier, MZI, optical logic gates.