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Emerging applications of wireless sensor networks require accurate event detection while coping with in-network congestion, delay, power and probability of false alarm (PFA) constraints. Dynamic spectrum access stands as a promising and spectrum-efficient communication approach for resource-constrained wireless sensor networks. In this paper, we propose a two tier sensor network where the lower tier...
Frequent changes in topology and link quality in mobile ad-hoc networks (MANETs) present challenging problems in achieving optimal performance. We propose a self-learning routing protocol based on Q-learning that makes use of Quality of Service (QoS) parameters such as Signal to Interference plus Noise Ratio (SINR), delay and throughput, to make routing decisions. At the same time, a Bayesian Network...
Carrier Sense Multiple Access (CSMA) has been widely used as a medium access control (MAC) scheme in wireless networks mainly due to its simple and totally distributed operations. Recently, it has been reported in the community that even such simple CSMA-type algorithms can achieve optimality in terms of throughput and utility, by smartly controlling its operational parameters such as backoff and...
For Wireless Multimedia Sensor Networks (WMSN), how to increase the throughput in constrained environments has become the main challenge. Multipath routing is a promising solution because it can improve the channel utilization rate, reduce transmission delay and balance the transmission load. To pursue high efficiency for a multipath routing scheme, we need to take the characteristics of wireless...
The operating system (OS) Jitter phenomenon has been considered an import and critical factor in high-performance distributed computing. In this paper, we present the results of an experimental study that quantifies the effects of different sources of OS Jitter in the Linux operating system. We use the design of experiments (DOE) method to conduct controlled experiments statistically planned. Different...
Data aggregation is generally considered an important method used to reduce traffic and increase lifetime of wireless sensor networks in both two- and three-dimensional space. It is challenging to develop efficient data aggregation solution for the wireless sensor networks since quality-of-service, such as end-to-end delay, is considered as a severe criterion required in many scenarios. In this paper...
In this paper, we analyse the delay performance of a point-to-multipoint cognitive radio network which is sharing the spectrum with a point-to-multipoint primary network. The channel is assumed to be independent but not identically distributed and has Nakagami-m fading. A constraint on the peak transmit power of the secondary user transmitter (SU-Tx) is also considered in addition to the peak interference...
In the past decade, multipath routing has been proposed to provide reliability for mobile ad hoc networks (MANETs). As wireless mesh networks become more and more popular, performance evaluation of different routing algorithms is required in static scenarios. Performance comparison between unipath routing and multipath routing is conducted in this paper. From the simulation results we find that multiple...
Body Sensor Networks (BSNs) enable continuous and remote health monitoring in medical applications. Inter-user interference is the major cause that deteriorates the reliable data transmission in BSNs when multiple BSNs are transmitting simultaneously in close proximity to one another. This paper presents an inter-user interference mitigation (IIM) method, which enables BSNs to adaptively reschedule...
Beaconing is an important technique for the broadcast of surveillance information, e.g., between aircraft, as well as for the exchange of neighborhood information in mobile ad-hoc networks. For aeronautical communication and surveillance, the scarcity of available spectrum is an important issue. Therefore, this paper compares the spectral efficiency of two advanced beaconing schemes to plain Aloha...
We focus on the problem of links scheduling in heterogeneous wireless sensor networks. Links scheduling becomes more difficult due to the diversity of workload among sensor nodes. An improper links scheduling strategy will lead to high end-to-end delay and then diminish the data availability. We assume the energy cost of state transition cannot be ignored, especially for wireless multimedia sensor...
In this paper we propose the channel assignment scheme for multi-channel wireless mesh network (WMN), where each mesh router is equipped with multiple radio interfaces. In real WMN the number of radio interfaces is much higher than the number of non-overlapping channels, which causes a lot of connections between mesh nodes operate on the same radio channel. Increasing number of simultaneous transmissions...
Different guard interval techniques for the Orthogonal Frequency Division Multiplexing (OFDM) transmission are suggested to reduce the interference between successive symbols (i.e. Inter-Symbol Interference, ISI) and interference between different carriers within the same symbol (i.e. Inter-Carrier Interference, ICI). In this paper, the impact of replacing the Cyclic Prefix (CP) by zeros insertion...
To resolve channel interference and "Deafness" problem in cognitive wireless mesh network, a new Cross-layer Design based on Link Quality for Cognitive Wireless Mesh Networks is proposed. When the node chooses the channel, it is not only in accordance with the rank of channels, but also based on link quality. In this way, cross-layer technology can be effectively achieved, and network performance...
In this paper, the influence of feedback channel delay on system throughput of the cooperative multi-cell system with adaptive beamforming selection is discussed. On the one hand, multi-cell cooperative processing (MCP) has the potential to boost spectral efficiency and improve fairness among users. However, the traditional centralized multi-cell cooperative scheme, where a central processing unit...
To deal with problems that queuing information is not included in cognitive information when performing Resource Allocation (RA), a dynamic cross-layer scheme is proposed for the multimedia cognitive radio (CR) system with Orthogonal Frequency Division Multiplexing (OFDM). In this scheme, we consider that several crucial factors influence the RA decision, including channel state information, interference...
In Wireless Local-Area Networks (WLANs), most of the wireless Access Points (APs) work at the full power level. So, the conflicting channels may have a significant and inevitable impact on throughput and transmission delay when the density of the APs is increasing. This paper proposes a power control algorithm, Dynamic Power Control called DPC based on NetFlow. DPC applies a fine tuning idea to get...
Due to overlapping frequency bands, IEEE 802.11a WLAN and Ultra Wide-Band systems potentially suffer from mutual interference problems. This paper proposes a method for inserting frequency notches into the IR-UWB power spectrum to ensure compatibility with WLAN systems. In contrast to conventional approaches where complicated waveform equations are used, the proposed method uses a dual-pulse frequency...
Interference management is an important issue due to the wide deployment of femtocells by subscribers. An elementary solution to the interference mitigation problem is to restrict transmission of pilot signals by femto base stations (BSs) which have no serving subscribers, i.e. idle listening state operation. However, the implementation of the idle listening state in a femto BS opens a possibility...
Inter-cell Interference (ICI) in the uplink of modern cellular communication systems with high frequency reuse is hard to predict, as fast scheduling and link adaptation lead to a high interference fluctuation. This fluctuation poses a big challenge for link adaptation algorithms that need an accurate SINR estimate to assign suitable modulation and coding schemes for transmission. To enable ICI prediction...
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