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Quality communication is a big challenge in mobile ad hoc networks because of a restricted environment for mobile devices, bandwidth-constrained radio connections, random mobility of connected devices, etc. High-quality communication through wireless links mainly depends on available bandwidth, link stability, energy of nodes, etc. Many researchers proposed stability and link quality methods to improve these issues, but they still require optimization. This study aims to contribute towards better quality communication in temporarily formed networks. The authors propose the stable and bandwidth aware dynamic routing (SBADR) protocol with the aim to provide an efficient, stable path with sufficient bandwidth and enough energy hold nodes for all types of quality of service (QoS) data communication.

The proposal made in this work used received signal strength from the media access control (MAC) layer to estimate the stability of the radio connection. The proposed path stability model combines the stability of the individual link to compute path stability. The amount of bandwidth available for communication at a specific time on a link is defined as the available link bandwidth that is understood as the maximum throughput of that link. Bandwidth as a QoS parameter ensures high-quality communication for every application in such a network. One other improvement, towards quality data transmission, is made by incorporating residual energies of communicating and receiving nodes in the calculation of available link bandwidth.

Communication quality in mobile ad hoc network (MANET) does not depend on a single parameter such as bandwidth, energy, path stability, etc. To address and enhance quality communication, this paper focused on high impact factors, such as path stability, available link bandwidth and energy of nodes. The performance of SBADR is evaluated on the network simulator and compared with that of other routing protocols, i.e. route stability based QoS routing (RSQR), route stability based ad-hoc on-demand distance vector (RSAODV) and Ad-hoc on-demand distance vector (AODV). Experimental outcomes show that SBADR significantly enhanced network performance in terms of throughput, packet delivery ratio (PDR) and normalized control overhead (NCO). Performance shows that SBADR is suitable for any application of MANET having random and high mobility.

QoS in MANET is a challenging task. To achieve high-quality communication, the authors worked on multiple network parameters, i.e. path stability, available link bandwidth and energy of mobile nodes. The performance of the proposed routing protocol named SBADR is evaluated by a network simulator and compared with that of other routing protocols. Statistical analysis done on results proves significant enhancement in network performance. SBADR is suitable for applications of MANET having random and high mobility. It is also efficient for applications having a requirement of high throughput.

SBADR shows a significant enhancement in received data bytes, which are 1,709, 788 and 326 more in comparison of AODV, RSAODV and RSQR, respectively. PDR increased by 21.27%, 12.1%, 4.15%, and NCO decreased by 9.67%, 5.93%, 2.8% in comparison of AODV, RSAODV and RSQR, respectively.

Outcomes show SBADR will perform better with applications of MANET such as disaster recovery, city tours, university or hospital networks, etc. SBADR is suitable for every application of MANET having random and high mobility.

This is to certify that the reported work in the paper entitled “SBADR: stable and bandwidth aware dynamic routing protocol for mobile ad hoc network” is an original one and has not been submitted for publication elsewhere. The authors further certify that proper citations to the previously reported work have been given and no data/tables/figures have been quoted verbatim from the other publications without giving due acknowledgment and without permission of the author(s).

The purpose of this paper is to propose a scheduling method called the “Hierarchical Asynchronous Harmonic Broadcasting (H‐AHB)” method, to reduce the waiting time for heterogeneous clients.

The authors analyze and evaluate the performance of the proposed H‐AHB method.

It was confirmed that the proposed method gives shorter average waiting time than the conventional methods.

A future direction of this study will involve making a scheduling method where the server broadcasts multiple videos.

In general broadcasting systems, the server broadcasts the same data repetitively and clients wait until the first portion of the data is broadcast. Although the server can deliver the data to many clients concurrently, clients have to wait until their desired data are broadcast.

The H‐AHB method further reduces waiting time by scheduling an effective broadcast that considers the number of clients' available channels.

The purpose of this paper is to propose a scheduling method called the “Asynchronous Harmonic Broadcasting Considering Commercial (AHB‐CC)” method, to reduce waiting time for continuous media data broadcasting.

The authors analyze and evaluate the performance of the proposed AHB‐CC method.

The authors confirm that the proposed method gives shorter average waiting times than the conventional methods.

A future direction of this study will involve making a scheduling method where the server concurrently broadcasts data and commercial contents. Also, maximum buffer size needs to be considered.

In general broadcasting systems, the server broadcasts the same data repetitively and clients wait until the first portion of the data is broadcast. Although the server can deliver the data to many clients concurrently, clients have to wait until their desired data are broadcast.

The AHB‐CC method presented in the paper further reduces waiting time by scheduling an effective broadcast that considers the playing time of commercial contents.

Coexistence of various wireless access networks and the ability of mobile terminals to switch between them make an optimal selection of serving networks for multicast groups a challenging problem. Since optimal network selection requires large dimensions of data to be collected from several network locations and sent between several network components, the scalability can easily become a bottleneck in large-scale systems. Therefore, reducing data exchange within heterogeneous wireless networks is important. The paper aims to discuss these issues.

The authors study the decision-making process and the data that need to be sent between different network components. To analyze the operation of the wireless heterogeneous network, the authors built a mathematical model of the network. The objective is defined as a minimization of multicast streams in the system. To evaluate the heuristic solutions, the authors define the upper and lower bounds to their operation.

The proposed heuristic solutions substantially reduce the usage of bandwidth in mobile networks and exchange of information between the network components.

The authors proposed the approach that allows network selection in a decentralized manner with only limited information shared among the decision makers. The authors studied how different sets of information available to decision makers influenced the performance of the system. The work also investigates the usage of multiple paths for multicast in heterogeneous mobile environments.

The purpose of this paper is to reduce the waiting time on webcast for selective contents, by proposing a scheduling method called the “contents prefetched broadcasting considering user participation” (CPB‐CP) method.

The authors analyze and evaluate the performance of the proposed CPB‐CP method.

It is confirmed that the proposed method gives shorter average waiting time than the conventional methods.

A future direction of this study will involve making a scheduling method in the case where the playing time of each content item is different.

In selective contents delivery, users may wait for the next bit of content to start playing after watching the previous one. In quiz programs, users may wait to receive the content data for their selected answer after they select their answer.

In the CPB‐CP method, when a provider node pulls out of the network while delivering contents, waiting time is reduced effectively by reconstructing a delivery schedule that considers the available bandwidth of each provider node.

Pervasive services and smart environments are becoming more and more popular as an ever‐increasing number of people enjoys these services typically by means of portable devices. These devices are battery‐fed and, thus, energy efficiency is a critical factor for the deployment of pervasive services. In this paper we focus on multimedia streaming services for mobile users. Specifically, we consider a scenario where mobile users with Wi‐Fi devices access the Internet to receive audio files from a remote streaming server. We propose a proxybased architecture and an energy‐efficient streaming protocol that minimize the energy consumption of the Wi‐Fi interface at the mobile device, while guaranteeing the real‐time constraints of the audio streaming. The experimental analysis performed on a prototype implementation shows that our solution allows an energy saving ranging from 76% to 91% of the total consumption due to the network interface. Moreover, it also preserves a good user‐level Quality of Service.

Convivo is a VoIP system designed to provide reliable voice communication for poor quality networks, especially those found in rural areas of the developing world. Convivo introduces an original approach to maintain voice communication interaction in the presence of poor network performance: an Interface‐ Adaptation mechanism that adjusts the user interface to reduce the impact of high latency and low bandwidth networks. Interface modes facilitate turn taking for high latency connections, and help to sustain voice communication even with extremely low bandwidth or high error rates. An evaluation of the system, conducted in a rural community in the Dominican Republic, found that Interface‐Adaptation helped users to maintain voice communication interaction as network performance degrades. Transitions from full duplex to voice messaging were found particularly valuable. Initial results suggest that as users get more experience with the application they would like to manually control transitions based on feedback provided by the application and their own perceived voice quality.

The Internet, with its requirement for high‐quality, high‐speed connections, places heavy demands on telecommunication infrastructure. In most LDCs, however, national and international Internet connectivity is in short supply: optical fibres may not be available, satellite links are limited and expensive, and internal telecommunication infrastructures are typically concentrated in a few main cities and present severe shortcomings in rural areas. These obstacles, together with lack of clear telecommunication policies and regulations and an internal market that is often closed to competition, result in a lack of investment and highly‐priced services, all of which impede Internet penetration. All the above‐mentioned elements are connected, and an intervention on one of them could positively impact on all the others. Improved, low‐cost, international Internet connectivity could transform this “vicious circle” in a “virtuous [Internet] circle”?

This paper aims to assess the use of electronic journal resource at the University of Dar es Salaam. The study involved the postgraduate students in the School of Education at the University of Dar es Salaam.

A combination of questionnaires for postgraduate students and interview for the reference librarians was used, whereby 100 postgraduate students and six reference librarians were involved in the study. SPSS and content analysis were used to analyse the data.

Major findings of the study reveal that majority of the students reported using electronic journal resources for various purposes including working on the assignments, research proposal writing, literature review, research report writing, current awareness, leisure and for extra exploration of ongoing scientific debates through peer-reviewed papers. The challenges encountered in the use of electronic journal resources include power outage, inadequate bandwidth, slow download speed, inability to access the resources from home, lack of training, lack of awareness, limited access to computers and difficulty in searching. Finally, the recommendations for improving the use of electronic journal resources are provided.

This is the first time an effort has been made to assess the use of electronic journal resources by postgraduate students in the School of Education at the University of Dar es Salaam. The study could be used to assess the postgraduate students’ need for electronic resources at the University of Dar es Salaam and other users in higher learning institutions.

Nanopore-based molecular sensing and measurement, specifically DNA sequencing, is advancing at a fast pace. Some embodiments have matured from coarse particle counters to enabling full human genome assembly. This evolution has been powered not only by improvements in the sensors themselves, but also in the assisting microelectronic CMOS readout circuitry closely interfaced to them. In this light, this paper aims to review established and emerging nanopore-based sensing modalities considered for DNA sequencing and CMOS microelectronic methods currently being used.

Readout and amplifier circuits, which are potentially appropriate for conditioning and conversion of nanopore signals for downstream processing, are studied. Furthermore, arrayed CMOS readout implementations are focused on and the relevant status of the nanopore sensor technology is reviewed as well.

Ion channel nanopore devices have unique properties compared with other electrochemical cells. Currently biological nanopores are the only variants reported which can be used for actual DNA sequencing. The translocation rate of DNA through such pores, the current range at which these cells operate on and the cell capacitance effect, all impose the necessity of using low-noise circuits in the process of signal detection. The requirement of using in-pixel low-noise circuits in turn tends to impose challenges in the implementation of large size arrays.

The study presents an overview on the readout circuits used for signal acquisition in electrochemical cell arrays and investigates the specific requirements necessary for implementation of nanopore-type electrochemical cell amplifiers and their associated readout electronics.