Abstract In this work, Attempts focused on improving the voice quality in VoIP toward packet loss effect. The main aimwas to find an efficient time scale modification method for compensating lost voice samples. This work started by introducingtypical voice codecs; then, some of the well-known voice codecs were applied to the low packet loss condition and theirintrinsic resistance was evaluated. Some... In this work, Attempts focused on improving the voice quality in VoIP toward packet loss effect. The main aimwas to find an efficient time scale modification method for compensating lost voice samples. This work started by introducingtypical voice codecs; then, some of the well-known voice codecs were applied to the low packet loss condition and theirintrinsic resistance was evaluated. Some time scale modification methods are applied for compensating the lost packet referredas packet loss concealment (PLC) method. Codec characteristics were surveyed to determine the best method for improvingthe quality. Evaluation of quality assessment was gained by ITU P.862.1 (narrowband PESQ) score in narrowband codecs.The results show that the quality of degraded voice significantly improved. Read More Read Less

Abstract Web-based laboratory has become a useful tool in Engineering and Science education. Many educationalinstitutions now days use web-based laboratory technology to conduct laboratory experiments for their students. This paperdiscusses the implementation of interactive Digital Electronics laboratories designed and implemented at University of Dares Salaam. Particularly, the implementation of Decoder Encoder experiment using interactive web-based laboratories. TheLabView 8.6 is used... Web-based laboratory has become a useful tool in Engineering and Science education. Many educationalinstitutions now days use web-based laboratory technology to conduct laboratory experiments for their students. This paperdiscusses the implementation of interactive Digital Electronics laboratories designed and implemented at University of Dares Salaam. Particularly, the implementation of Decoder Encoder experiment using interactive web-based laboratories. TheLabView 8.6 is used on the NI ELVIS platform. The use of web-based laboratory came after realizing the difficulties imposedby the traditional laboratories. Web-based laboratories allow students and educators to interact with real laboratory equipmentlocated anywhere in the world at anytime. The Decoder Encoder experiment is one of the four digital experiments designedand deployed using web-based technology at university of Dar es Salaam. Read More Read Less

Abstract In this paper, we propose a model for resource allocation in cognitive radio network (CRN) and provide a securecommunication between primary user (PU) and secondary users (SUs). Here, PUs takes the help of the mobile agents (MAs)for calling the auction on behalf of PU Access Point (PUAP) and work as interface between PUAP and SU. MAs handlemultiple task to make... In this paper, we propose a model for resource allocation in cognitive radio network (CRN) and provide a securecommunication between primary user (PU) and secondary users (SUs). Here, PUs takes the help of the mobile agents (MAs)for calling the auction on behalf of PU Access Point (PUAP) and work as interface between PUAP and SU. MAs handlemultiple task to make the system fast, redundant, secure and robust. The problem is modeled using cooperative game theorybetween the MAs, MAs make the system distributed and simplifies the life of PUAP. MAs analyzes the behavior of the SU in themultiple aspects and forward the collected data to PUAP. The existence of MAs with the PUAP increase the efficiency of themodel. Read More Read Less

Abstract At present, the work of any modern organization, including Universities, uses a wide variety of communicationtechnologies, such as instant messaging, email, voice mail, cellular phone, SMS, Traditional telephony, IP-telephony, videoconferencing, and pager. Each means of communication has its own sets of features, and refusing to use any of them mayreduce the efficiency. Each of these technologies requires different resources for... At present, the work of any modern organization, including Universities, uses a wide variety of communicationtechnologies, such as instant messaging, email, voice mail, cellular phone, SMS, Traditional telephony, IP-telephony, videoconferencing, and pager. Each means of communication has its own sets of features, and refusing to use any of them mayreduce the efficiency. Each of these technologies requires different resources for implementation depending on the type of thetechnology. For the end user such variety means usage of multiple heterogeneous terminals and software. To improve thecommunication efficiency and to solve the problem of integration of various technologies, the concept of unified communications(UC) was developed. This paper presents the unified communications technologies and investigates the topology, infrastructureand resources for implementing unified communications system over Mosul University network. The work studies the abilityto and types of UC technologies to be adopted for this network. Read More Read Less