The Contributory Effect of Latency on the Quality of Voice Transmitted over the Internet

Deployment of Voice over Internet Protocol (VoIP) is rapidly growing worldwide due to the new services it provides and cost savings derived from using a converged IP network. However, voice quality is affected by bandwidth, delay, latency, jitter, packet loss e.t.c. Latency is the dominant factor that degrades quality of voice transfer. There is therefore strong need for a study on the effect of Latency with the view to improving Quality of Voice (QoV) in VoIP network. In this work, Poisson probability theorem, Markov Chain, Probability distribution theorems and Network performance metric were used to study the effect of latency on QoS in VoIP network. This is achieved by considering the effect of latency resulting from several components between two points in multiple networks. The NetQoS Latency Calculator, Net-Cracker Professional® for Modeling and Matlab/Simulink® for simulating network were tools used and the results obtained compare favourably well with theoretical facts

Teletraffic Modeling of Cdma Systems

This paper presents teletraffic modeling of Code Division Multiple Access (CDMA) systems that enabled the analysis of such systems capacity. Analytical tools aided by software model that assisted in analysis of the system performance, capacity estimation, dimensioning and design of CDMA networks were achieved. This work, therefore, focused on modeling telephone traffic for analysis of CDMA cellular network capacity. We developed an analytical expression for blocking probability and consequently that for the determination and analysis of the capacity of CDMA networks. The analyses of obtained results showed how interference determined the capacity of CDMA networks and therefore proved that the capacity was not hard limited, but depended on predetermined quality of service for the network. Also, the result showed how the capacity of the network, in terms of number of subscribers, can be estimated for CDMA networks. Graphical results generated from the blocking model showed the effect of variations in interference parameters on CDMA capacity. The Erlang capacity from the model was adapted into Erlang B formula to estimate capacity in terms of channels, and the number of subscribers a typical CDMA sector could accommodate

Optimized Remote Network Using Specified Factors As Key Performance Indices

This paper discuss the implementation of an optimized remote network, using latency, bandwidth and packet drop rate as key performance indicator (KPI) to measure network performance and quality of service (QoS). We compared the network performance characteristics derived on the Wide Area Network (WAN) when using Fiber, VSAT and Point-to-Point VPN across the internet respectively as the network infrastructure. Network performance variables are measured across various links (VAST, Fiber and VPN across the internet) and the corresponding statistical data is analyzed and used as base-line for the optimization of a corporate network performance. The qualities of service offered on the network before and after optimization are analyzed and use to determine the level of improvement on the network performance achieved

Managing and Improving Upon Bandwidth Challenges in Computer Network

Managing the bandwidth of a computer network is always faced with great challenges. This research was necessitated by the urgent need to manage the University network currently experiencing congestion in both the local LA� and on the internet backhaul with a view to improving network performance and reduce the huge recurrent on the WA� link. However, there exists various ways that have been deployed towards solving these problems. In this paper we examined existing bandwidth management, effect of limited bandwidth on the network performance and profound solutions of techniques that enhanced or improved the bandwidth efficiency. Also, included in this research work are the studies of the effect of limited bandwidth on work load, type of protocol used and the effect of network congestion on the quality of service of a Wide Area �etwork (WA�). By comparison, from the modeling of the effect of work load and limited bandwidth on the throughput of a wide area network based on experimental simulation and real time simulation scenarios, some observations were made and recommendation of solutions were given from the analyzed results

Suitability of Using Agbarha Clay for Drilling Mud Formulation in Oil and Gas Industry

In this research, a locally sourced clay from Niger-Delta Agbarha clay deposit formation was processed and treated to meet up with API standard specification for drilling fluid. Clay concentrations of 17.5 g, 21.0 g and 24.5 g of the local mud (Agbarha clay) and foreign Bentonite mud was prepared and analyzed using a standard measuring techniques. Laboratory analyses of the Properties of the Sample Mud (Agbarha clay) was compared with that of API Numerical Value Specification before and after beneficiation. The result shows that sample mud Weight, Apparent Viscosity (cp), Plastic Viscosity, Yield Point, Gel Strength (10 sec), Gel Strength (10min) showed values lower or a little short of API minimum numerical value standard while pH, Sand Content and ―n‖ factor give a values that are higher than thatof standard API minimum numerical value after aging for 48 hrs without beneficiation. Therefore, there is a need to beneficiate this local mud sample (Agbarha clay) to meet that of API standard specification. After beneficiation with 5g Hydroxyl Ethyl Cellulose (HEC), the sample mud sand content remains the same; Mud weight, Apparent Viscosity, Plastic Viscosity, Yield Point, Gel Strength(10sec) Gel Strength (10min), ―n‖ factor increased, pH of the mud sample reduced; all to values within API numerical value specification for standard drilling mud. Based on this research, Agbarha clay can therefore be recommended for formulation of drilling mud and can also serve as a substitute to foreign Bentonite mud. This will conserve foreign exchange, generate more employment and also enhance Nigerian local content development in the drilling component of oil and gas industry

Developed Model to Control Congestion on Converge Network

Congestion control techniques like Active Queue Management (AQM), Carrier Sense Multiple Access/Carrier Detection (CSMA/CD) have not proven to be very efficient in the presence of overwhelming complex converge network. Thus, vast packets in a complex converged network leads to collisions, network degradation and high degree of packet loss. Bandwidth utilization factor has a high effect on the network such that controlling the level of utilization via the management of the number of users and the amount of packets on the network rendered the latency very insignificant. As a consequence of this, high throughput and very minimal packet loss was achieved in the experiment. This was confirmed analytically by varying the utilization factor between 40% and 90% while keeping other parameters in the experiment constan

Antimicrobial Susceptibility Pattern of Clinical Isolates of Escherichia coli and Proteus mirabilis Using Cefepime in Ogbomoso, Nigeria.

The challenge of Cefepime resistance in developing countries is substantial and likely to grow. Emergence of Cefepime-resistant bacteria has increased and managemen

MasakhaPOS: Part-of-Speech Tagging for Typologically Diverse African languages

In this paper, we present AfricaPOS, the largest part-of-speech (POS) dataset for 20 typologically diverse African languages. We discuss the challenges in annotating POS for these languages using the universal dependencies (UD) guidelines. We conducted extensive POS baseline experiments using both conditional random field and several multilingual pre-trained language models. We applied various cross-lingual transfer models trained with data available in the UD. Evaluating on the AfricaPOS dataset, we show that choosing the best transfer language(s) in both single-source and multi-source setups greatly improves the POS tagging performance of the target languages, in particular when combined with parameter-fine-tuning methods. Crucially, transferring knowledge from a language that matches the language family and morphosyntactic properties seems to be more effective for POS tagging in unseen languages

The Society for Environmental Geochemistry and Health (SEGH): building for the future.

The challenges of sustainable development are ever more pressing, and the skills, interests and capabilities of the SEGH member are well-placed to continue to make more meaningful contributions to the environment, society and well-being. We reflect on the historical development of the society, its response to the dynamic international research landscape and the great opportunities ahead. In 2018, SEGH implemented a new board structure after 2–3 years of consultation, with approval of a new constitution and a new strategy across the large number of international board members. While regions were represented by sections in Europe, Asia/Pacific and the USA, the structure required renewal in order to be more representative of the distribution of members and website traffic that had evolved in preceding years. In addition, the society wanted to improve its position for future growth opportunities across rapidly developing regions