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Running a Network Management Protocol is imperative to ensure network connectivity and stability especially in highly dynamic environment of future Cognitive Radio Sensor Networks. Such protocols have to be characterized by their light overhead in terms of energy, communication and implementation. A solution in this respect is hereby proposed to enable a node in a multichannel environment to quickly...
The use of cluster-based networks is a well known technique to prolong the lifetime of wireless sensor networks (WSNs). In a cluster-based network, a node can be partitioned into a number of small groups called clusters. Each cluster has a cluster-head (CH) node which transmits data collected by each member to the sink node. One of the important issues in cluster-based networks are determining the...
Preserving the requested k-coverage for Wireless Sensor Networks while prolong the network lifetime is a major challenge. The network must provide the required k-coverage degree to ensure the quality of the monitored area with a few active sensors to reduce the energy usage. In this paper, we propose DkCS, an energy-efficient algorithm to prolong the network lifetime while preserving the required...
In multi-channel wireless ad-hoc network, the nodes need to negotiate the channel reservation. Preparing the control channel is one of the strategies for the channel reservation. When the control channel congests due to frame collisions, the control channel is bottleneck for obtaining high throughput. This paper proposes a MAC protocol for multi-channel wireless ad-hoc network for frame collision...
This paper presents the investigation on the effect of two main parameters of a circular polarized patch antenna by using notch technique. The results show that this technique can improve the performance of return loss and gain of the patch antenna. The operating frequency of the proposed antenna is 2.4GHz with 32.66MHz of bandwidth and return loss is −49.63dB. The antenna had been designed and simulated...
Wireless Sensor Networks (WSN) which is capable in sensing, storing, processing and transmitting data has been widely applied in providing effective surveillance. Optimum sensor nodes placement in the surveillance area is needed to optimise the cost and efficiency of deployment. The positions of sensor nodes should be able to provide maximum coverage with longer lifetime. This paper proposed a sensor...
Different Medium Access Control (MAC) Protocols for Wireless Sensor Networks (WSNs) have been proposed over the last few years. IEEE 802.15.4 MAC protocol standard is designed for low-power, low-cost, and low-rate Wireless Personal Area Networks (LR-WPANs). The contention period of IEEE 802.15.4 standard consists of Contention Access Period (CAP) and Contention Free Period (CFP). CAP utilizes Carrier...
Cognitive Radios have been proposed as a novel technology to improve the spectrum utilization in wireless transmissions. In self-organized network such ad-hoc cognitive radio networks (AHCRNs), the resource allocation (e.g., power, and channel) rise up several challenges due to rapid utilization of the available spectrum. In this paper, we consider noncooperative game theory to solve the power allocation...
Orthogonal frequency division multiplexing (OFDM) is a robust transmission technique to combat the influence of wireless fading channels. However, OFDM suffers from high peak-to-average power ratio (PAPR) that significantly reduces the efficiency of the high power amplifier (HPA). This paper reviews the performance of few PAPR reduction techniques that are mostly based on Selected mapping (SLM), and...
Due to the sharp rise in computer network attacks through botnets, current security monitoring tools will be insufficient for effective botnet traffic detection. In fact, most of the existing tools are text-based and there is a lack of effective user friendly interface that can facilitate detection of botnet traffic in large datasets. Moreover, most of these tools are based on reactive approaches...
Orthogonal frequency division multiplexing (OFDM) is widely implemented in high data rate wireless applications due to its favourable properties. The main disadvantage associated with OFDM is high peak to average power ratio (PAPR). Although numerous schemes have been proposed to solve the PAPR problem, no specific PAPR reduction scheme can be considered as the best solution. The aim of this paper...
MUROS using high order modulation (HOM) is one of techniques for improving speech efficiency for 3GPP GERAN evolution. However, the conventional HOM for MUROS scheme shows high complexity because of the change of modulation format. Therefore, in this paper, an improved HOM scheme for the MUROS is proposed which employs a repetition transmission using surplus bits.
The aim of Long Term Evolution-Advanced (LTE-A) is to support a maximum throughput exceed 1 Gbps to the increase in data usage due to smart phones and bandwidth up to 100 MHz to an exponential growth in video downloads. LTE-A downlink physical layer allows a mobile to transmit and receive on up to four component carriers (CCs) in non-contiguous CCs case, each of which has a maximum bandwidth of 20...
Properties of substrate material play an important role in the design of reflectarray antenna. In this work linear and non-linear dielectric properties of substrate materials are discussed thoroughly. Rogers RT/d 5880 and K-15 nematic are used as linear and non-linear dielectric materials respectively, to design different reflectarray resonant elements in X-band frequency range. Simulated and measured...
Mobile WiMAX has the capability to support high transmission rate at vehicle speed and provides quality of service (QoS) for different applications. However, allocating the limited resources in such wireless network to different application with variant QoS is highly complex and challenging. Many resource allocation schemes have been proposed for different wireless based network. In most cases the...
The growing energy consumption in wireless networks driven by dramatic increases in mobile users and network traffic, are putting mobile operators under immense challenges towards meeting the demands of both cost reduction and environment conservation. The network Energy Efficiency (EE) considers not only energy consumed by the base station (BS), but also the capacity and coverage of the network....
Stereoscopic video as the simplest form of 3D video is already being used in consumer devices such as 3DTV and 3D mobile phone. When the 3D video from the 3D mobile phone is compressed and transmitted over error prone channels, error propagation due to packet loss leads to poor 3D visual quality. The objective of the paper is to provide error resilience 3D video using the well known multiple description...
One of the current most significant active research areas in wireless communication technologies is Wireless Sensor Network (WSN). WSN is widely adopted in the ubiquitous networking due to its large applications in different fields such as healthcare, agriculture, livestock monitoring, and etc. WSN is labeled as less reliable due to few drawbacks such as energy consumption, networking cost, mobility...
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