Wireless sensor networks are distributed network structures in which many sensor nodes connected to each other through a wireless environment. Wireless communication is transmission between a transmitter and a receiver without any cable connection, via light or electromagnetic waves. This paper presents a performance analysis of different topologies supported by the IEEE802.15.4/ZigBee standard were compared based on throughput, data traffic sent and data traffic received parameters using Riverbed modeler simulator. The Simulation has been carried out for different topologies of Wireless Personal Area Network (WPAN). In the fixed nodes communication, cluster-tree, mesh and star topologies have been considered using single coordinator. Finally this paper presents, the cluster tree topology is more efficient and best suited compared with mesh and star topologies for IEEE802.15.4/Zigbee standard. Moreover, the cluster tree topology covers more area compared with other topologies. The cluster tree topology is suitable for different applications such as environment monitoring, volcano monitoring, air pollution and habitat monitoring.

Text-to-speech (TTS) synthesis involves creating machines that can talk. It is the process of automatically converting written text into spoken speech. TTS systems are important in human-computer interaction, and they have become more prominent with the advancement of computer technology. There has been a growing demand for speech applications in various areas such as telemedicine, robotics, Google Assistant, and other fields, especially during the Covid-19 era. It is clear that the existing speech technology is not good enough for users. Many speech applications still use pre-recorded prompts instead of text-to-speech because the quality of text-to-speech isn't good, and it can't pronounce non-standard words. In this study, a dependable and effective approach is proposed for creating speech synthesis voices that are specialized for specific domains and can handle non-standard words. This involves developing lexicon rules for non-standard words. By constructing databases that are closely related to the specific domain of the speech application, concatenative unit selection synthesis techniques, implemented using the festival/festvox tool, can be utilized to achieve high-quality, intelligible, and natural speech synthesis within the targeted domain. And the quality of proposed voice model is measured using Melcepstral distortion as an objective metric and Mean Opinion score as a subjective metric.