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Wireless sensor networks are appealing to researchers due to their wide range of application potential in areas such as target detection and tracking, environmental monitoring, and tactical systems. However, lower sensing ranges result in dense networks, which bring the necessity to achieve an effcient medium access protocl subject to power constraints. Various MAC protocols with different objectives...
Wildlife sounds provide relevant information for non-intrusive environmental monitoring when Wireless Sensor Networks (WSNs) are used. Thus, collecting such audio data, while maximizing the network lifetime, is a key challenge for WSNs. In this work, we propose a methodology that applies Compressive Sensing (CS) aiming at collecting as little data as possible to allow the signal reconstruction, so...
In Wireless Sensor Network (WSN) researches, WSN routing algorithm is one of the hot issues. This article focuses on GPSR (Greedy Perimeter Stateless Routing) and uses the NS2 (Network Simulator-2) to simulate both GPSR and the improved algorithm GPSRI (GPSR-Improved). Consequently, we have compared GPSRI with GPSR in terms of important parameters, such as data transmit delay and data relay hops....
The hidden terminal problem in wireless sensor network (WSN) is one of the main causes of collision. Even though RTS/CTS handshaking has been implemented in CSMA/CA standard to alleviate the problem, it does not solve the collision completely. Moreover, it induces an issue called false blocking problem. Unaware of a busy status of a hidden receiver, adjacent nodes which can be potential senders will...
In order to maintain a small, stable backlog at the router buffer, active queue management (AQM) algorithms drop packets probabilistically at the onset of congestion, leading to backoffs by Transmission Control Protocol (TCP) flows. However, wireless losses may be misinterpreted as congestive losses and induce spurious backoffs. In this paper, we raise the basic question: Can AQM maintain a stable,...
Wireless sensor networks usually consist of a large number of very small, energy-constrained sensor nodes. The nodes capture information from their immediate environment to send it to a destination node (sink) in a timely manner.
Opportunistic routing is widely known to have substantially better performance than traditional unicast routing in wireless networks with lossy links. However, wireless sensor networks are heavily duty-cycled, i.e. they frequently enter deep sleep states to ensure long network life-time. This renders existing opportunistic routing schemes impractical, as they assume that nodes are always awake and...
In many sensor network applications, sink node needs to actively communicate with other sensor nodes in order to perform event detection operations. For those applications, there is usually a delay bound associated with them and require the messages sent to be received within a designated time bound. In this paper, we address the event detection problems in an energy harvesting sensor network where...
In order to access to the time-Delay Performance of the Wireless Sensor Network, respectively preformed the time-delay experiment, simulation and theoretical analysis from the following aspects: the hops and hop spacing, MAC dormancy mechanism, back-off time and transmitted power, etc. Obtained the relations between the time-delay and the above factors. Systematically summed up the time-delay rules...
In hierarchical networks, nodes are separated to play different roles such as CHs and cluster members. Each CH collects data from the cluster members within its cluster, aggregates the data and then transmits the data to the sink. Each algorithm that is used for packet routing in quality of service (QoS) based applications should be able to establish a tradeoffs between end to end delay parameter...
Traditionally, transmission power is adjusted dynamically to overcome unreliability over lossy links in energy-constrained Wireless Sensor Networks (WSNs). The network node increases its transmission power to achieve immunity against link errors or lowers the power to save energy and prevent interference. Through systematic analysis, we illuminate that it adversely affects the channel contention,...
For smaller scale wireless sensor networks (WSN) it has been clearly shown that a single mobile sink can be very beneficial with respect to the network lifetime. Yet, how to plan the trajectories of many mobile sinks in very large WSNs in order to simultaneously achieve lifetime and delay goals has not been treated so far. In this paper, we delve into this difficult problem and propose a heuristic...
The main task of most deployed wireless sensor networks is data collection. While a number of solutions have been designed for static networks, there are currently no widely used data collection algorithms for mobile sensor networks. In this paper, we concentrate on scenarios where many nodes, both data sources and sinks, move along a certain track in one direction, a scenario that is common in sports...
Wireless sensor networks (WSNs) can be used for a variety of applications. For many applications, a high reliability and low delay are required. Due to lossy feature of wireless channel, providing a reliable communication is very challenging. The most frequently used approach for providing the reliability is to use the acknowledgement based retransmission mechanism which increases the end-to-end delay...
Wireless sensor networks (WSN) are one of most interesting emerging technologies. WSN can be used to perform monitoring, surveillance, sensing and measuring operations. In order to further increase these applications, minimizing energy consumption is one of the most critical issues. Therefore, accurate energy model is required for the evaluation of wireless sensor networks performance. In this paper,...
The wireless sensor network (WSN) is one new hot spot for both research and industry. However, the energy problem has been becoming a challenge in practical applications for WSN because the sensor nodes are supplied with energy by batteries which are difficult to be recharged and replaced. So many researches are taken on reducing the energy consumption of WSN nodes. Medium Access Control (MAC) layer...
Sensor networks are exposed to hostile environments that may cause failures of single nodes and communication links which affect the whole network. Localizing the cause of the problem in space and time requires to collect diagnostic data from the network. Due to resource and energy constraints, however, it is not possible to continuously collect detailed diagnostic data from all nodes. We therefore...
Energy consumption in wireless sensor networks (WSN) was always a basic constraint to respect. But, with the appearance of Wireless Multimedia Sensor Networks (WMSN), another basic constraint comes from added, which is the traffic performance in terms of delay, throughput, and Packet Delivery Rate (PDR). The choice of channel access method can help us to better respond the two constraints in WMSN...
Nature-inspired routing protocols have been subject to a great research activity. Their decentralized nature and low requirements make them highly suitable for Wireless Sensor Networks (WSN) where individual nodes operate without central control and without global overview of the network status to achieve global tasks. This paper proposes a hybrid QoS routing protocol for WSN based on a customized...
Data dissemination over long distances in urban scenarios is the foundation of many VANET applications, but rapid shifting in network topology, unstable quality of wireless communication and channel capacity constraints of VANETs pose many challenges to data dissemination. In response, we propose a connectivity-aware data delivery mechanism on the basis of an improved greedy broadcasting. Moreover,...
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