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Formal localized reactive model of Subnet-based Failure Recovery of Sparsely Connected Network for monitoring less critical areas of border is presented in this paper to reduce monitoring by soldiers. It involves Wireless Sensor and Actor Networks (WSANs) partitioned into subnets. The topology of the subnets is sparsely connected in less critical areas where fewer sensors and actors are required....
Recently there is a growing interest of incorporating cellular architecture (with wired base stations and last-hop wireless connections) into fieldbuses to support mobile real-time applications. A promising trend is that such cellular fieldbuses will go multichannel multiradio, due to the wide availability of cheap multichannel commercial-off-the-shelf (COTS) wireless nodes, and the rise of 4G and...
Ad hoc networks are promising technologies that is easily deployable and dynamically adaptable. However, ad hoc networks can experience severe impairments caused by node motion in the case of Mobile Ad hoc NETworks (MANETs) or scarce node density in the case of Wireless Mesh Networks (WMNs). In this work, we are mainly interested in WMN. The WMN consists of wireless mesh clients (WMCs) and wireless...
The basic challenge of data centers is how to interconnect a huge number of servers while guaranteeing the performance of the network. Flatnet is a promising data center architecture that has proved its efficiency to connect a scalable number of servers and to achieve a high network capacity, fault-tolerance and low-cost while using only one network layer. However, its long path length impacts the...
Growth of elderly population induces the increasing demands for high-quality healthcare services, wireless body area networks (WBANs) has emerged as a promising solution for monitoring of patients vital life signs parameters. Reliability and extending the lifetime are considered amongst the important and challenging issues in WBANs. The standard IEEE 802.15.4 is considered as the most used MAC protocol...
Thanks to their flexibility and their simplicity of installation, Wireless Mesh Networks (WMNs) allow a low cost deployment of network infrastructure. They can be used to extend wired networks coverage allowing connectivity anytime and anywhere. However, WMNs may suffer from drastic performance degradation (e.g., increased packet loss ratio and delay) because of interferences and congestion. Generally,...
In this paper we propose two different topologies for dual band six-port junctions. They are designed in Microstrip technology to operate at 1.5 GHz and 2.7 GHz carrier frequencies. The results of the EM simulations revealed a good matching for both topologies. However, the performance analysis in terms of frequency bandwidth, reflection loss and qe points demonstrated the superiority of the non symmetrical...
In this study, a novel multi-level type bidirectional half-bridge inverter for wireless power transfer applications is presented. The proposed converter provides high power application by splitting the voltage in each switch. The converter topology is explored to reveal the maximum efficiency points with a variable phase-shift function between the dual active level (DAL) switches. The analysis of...
When stricken by a large-scale disaster, the efficiency of disaster response operation is very critical to lifesaving. However, communication systems, such as cellular networks, usually crashed due to various causes making coordination among disorganized disaster responders extremely difficult. Unfortunately, rapid deployment of many existing emergency communication systems relies on a good transportation...
MAC interference in IEEE 802.11 network is caused by overlapped signal ranges and complex carrier sensing topology. Data throughput and wireless coverage increases by sender's transmission power in free space and this property identified the transmission power as a standard indication for wireless efficiency; however, increased transmission power also implies longer reachable signal range and higher...
The purpose of this paper is improving the efficiency of data traffic management in wireless communication systems with distributed topological structure. Improvement of the efficiency of data traffic management can be possible using the principles that allow to take into account information about the state of the system at various levels of model OSI. As a result of the experimental test the efficiency...
This work aims to investigate the performance of millimetre wave (mm-wave) broadband wireless access for seamless integration with the (ultra-dense) WDM infrastructure. By using two uncorrelated lasers at the coherent receiver, a simple implementation is obtained, which can additionally be improved, if thermally uncooled lasers are used. Although such asynchronous receiver design is mildly affected...
To this day, Cloud computing continues its explosive growth. Nevertheless, with the exceptional evolution of demands, data centers are suffering from congestion problems. To deal with these resource limitations, first, we put forward a novel Hybrid Data Center Network (HDCN) Architecture enabling high throughput wireless (IEEE 802.11 ad) and wired (IEEE 802.3) transmissions. Secondly, we propose a...
Visible light communication (VLC), a novel technology that enables standard Light-Emitting-Diodes (LEDs) to transmit data, is gaining significant attention. In the near future, this technology could enable devices containing LEDs-such as car lights, city lights, screens and home appliances-to form their own networks. VLC, however, is currently limited to point-to-point communication. To unleash VLC's...
This paper proposes an architecture that uses the ultra-low power Bluetooth Low Energy (BLE) wireless standard and a hybrid topology to reduce power consumption in IOT based wireless sensor networks (IOTWSN). A lot of work has been done in the field of Wireless Sensor Networks (WSN) in recent years. Efforts to make efficient, low cost, scalable and easily deployable WSN have been on going. In order...
Simulation is the most widely used tool for evaluating network protocols in multihop wireless networks, yet this has so far been limited due to a lack of models for creating a wide range of scenarios of mobile nodes moving about. For example, for evaluating multihop routing protocols, the frequently used Random Waypoint model can only effectively be used in scenarios with relatively high node density,...
Internet connectivity in most rural African areas has been viewed as a major challenge due to lack of reliable power, scarcity of network expertise and expensive installation of network equipment. With the rapid development of wireless technologies, Wireless Mesh Network (WMN) has emerged as a promising networking infrastructure, bridging the digital divide between the urban and rural areas. However,...
There have been increases in the elderly population worldwide, and this has been accompanied by rapid growth in the health-care market, as there is an ongoing need to monitor the health of individuals. Wireless body area networks (WBANs) consist of wireless sensors attached on or inside the human body to monitor vital health-related problems, e.g., electrocardiograms (ECGs), electroencephalograms...
In this study, analysis of a bi-directional half-bridge inverter for wireless power transfer applications is realized. The presented converter topology is explored to reveal the maximum efficiency points with a variable phase shift function between the dual active bridge (DAB) switches. The examination of the converter is provided in terms of variable load and coupling co-efficient factor at a constant...
Integrated charger topologies that have been researched so far are with the dc-dc converters and the charging functionality usually have no isolation in the system. Isolation is an important feature that is required for user interface systems that have grid connections and therefore is a major limitation that needs to be addressed along with the integrated functionality. This study features a unique...
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