206 research outputs found
THE EFFECT OF INTERACTIONS BETWEEN PROTOCOLS AND PHYSICAL TOPOLOGIES ON THE LIFETIME OF WIRELESS SENSOR NETWORKS
Wireless sensor networks enable monitoring and control applications such weather sensing, target tracking, medical monitoring, road monitoring, and airport lighting. Additionally, these applications require long term and robust sensing, and therefore require sensor networks to have long system lifetime. However, sensor devices are typically battery operated. The design of long lifetime networks requires efficient sensor node circuits, architectures, algorithms, and protocols. In this research, we observed that most protocols turn on sensor radios to listen or receive data then make a decision whether or not to relay it. To conserve energy, sensor nodes should consider not listening or receiving the data when not necessary by turning off the radio. We employ a cross layer scheme to target at the network layer issues. We propose a simple, scalable, and energy efficient forwarding scheme, which is called Gossip-based Sleep Protocol (GSP). Our proposed GSP protocol is designed for large low-cost wireless sensor networks with low complexity to reduce the energy cost for every node as much as possible. The analysis shows that allowing some nodes to remain in sleep mode improves energy efficiency and extends network lifetime without data loss in the topologies such as square grid, rectangular grid, random grid, lattice topology, and star topology. Additionally, GSP distributes energy consumption over the entire network because the nodes go to sleep in a fully random fashion and the traffic forwarding continuously via the same path can be avoided
Dynamic Power Splitting Policies for AF Relay Networks with Wireless Energy Harvesting
Wireless energy harvesting (WEH) provides an exciting way to supply energy
for relay nodes to forward information for the source-destination pairs. In
this paper, we investigate the problem on how the relay node dynamically
adjusts the power splitting ratio of information transmission (IT) and energy
harvesting (EH) in order to achieve the optimal outage performance. According
to the knowledge of channel state information (CSI) at the relay, optimal
dynamic power splitting policy with full CSI and partial CSI are both provided.
Finally, through simulations, the proposed power splitting policies can improve
the outage performances and the policy with full CSI achieves the best
performance. It is also shown that the policy with partial CSI can approach the
policy with full CSI closely and incurs far less system overhead.Comment: accepted by IEEE ICC 2015 - Workshop on Green Communications and
Networks with Energy Harvesting, Smart Grids, and Renewable Energie
Controlling the degradation of wireless sensor networks
With the fast expansion of Wireless Sensor Networks (WSNs) and the increasing emergence of new scenarios and applications, extending their lifetime is crucial. Usually, WSN developers use generic algorithms and deployment arrangements without considering the specific needs of their network's application. Taking this application into account can result in a significant enhancement of performance, both in terms of increasing the lifetime and improving the quality of service (QoS). Furthermore, most WSN developers do not consider the final behavior of the network when nodes are nearly depleted and resources are scarce. In this paper we introduce the concept of the controlled degradation of the network, to refer to the strategies aimed at managing this deterioration process. The existing definitions of the network lifetime do not normally consider the specific purpose or application for which the WSN is intended. Thus, they are not suited to describe and test controlled degradation strategies. Consequently, we propose a new formal and comprehensive definition for the network lifetime. Finally, this work presents a proof of concept that confirms our statements and reinforces the potential of this research line
Load balancing and lifetime maximization in WSN
Workshop Univ Kyushu-INPTStrategies that balance the energy consumption of the nodes and ensure maximum network lifetime by balancing the load are proposed and analyzed. Multiple transmission power levels are used. We studied an optimal solution for calculating the hop-by-hop traffic proportions for the particular case of nodes having just two transmission power levels, and compared the results given by the heuristics with those from the optimal analytical case
Network Lifetime Maximization With Node Admission in Wireless Multimedia Sensor Networks
Wireless multimedia sensor networks (WMSNs) are expected to support multimedia services such as delivery of video and audio streams. However, due to the relatively stringent quality-of-service (QoS) requirements of multimedia services (e.g., high transmission rates and timely delivery) and the limited wireless resources, it is possible that not all the potential sensor nodes can be admitted into the network. Thus, node admission is essential for WMSNs, which is the target of this paper. Specifically, we aim at the node admission and its interaction with power allocation and link scheduling. A cross-layer design is presented as a two-stage optimization problem, where at the first stage the number of admitted sensor nodes is maximized, and at the second stage the network lifetime is maximized. Interestingly, it is proved that the two-stage optimization problem can be converted to a one-stage optimization problem with a more compact and concise mathematical form. Numerical results demonstrate the effectiveness of the two-stage and one-stage optimization frameworks
Wireless Power Charging Control in Multiuser Broadband Networks
Recent advances in wireless power transfer (WPT) technology provide a
cost-effective solution to charge wireless devices remotely without disruption
to the use. In this paper, we propose an efficient wireless charging control
method for exploiting the frequency diversity in multiuser broadband wireless
networks, to reduce energy outage and keep the system operating in an efficient
and sustainable state. In particular, we first analyze the impact of charging
control method to the operating lifetime of a WPT-enabled broadband system.
Based on the analysis, we then propose a multi-criteria charging control policy
that optimizes the transmit power allocation over frequency by jointly
considering the channel state information (CSI) and the battery state
information (BSI) of wireless devices. For practical implementation, the
proposed scheme is realized by a novel limited CSI estimation mechanism
embedded with partial BSI, which significantly reduces the energy cost of CSI
and BSI feedback. Simulation results show that the proposed method could
significantly increase the network lifetime under stringent transmit power
constraint. Reciprocally, it also consumes lower transmit power to achieve
near-perpetual network operation than other single-criterion based charging
control methods.Comment: This paper had been accepted by IEEE ICC 2015, Workshop on Green
Communications and Networks with Energy Harvesting, Smart Grids, and
Renewable Energie
An Energy Driven Architecture for Wireless Sensor Networks
Most wireless sensor networks operate with very limited energy sources-their
batteries, and hence their usefulness in real life applications is severely
constrained. The challenging issues are how to optimize the use of their energy
or to harvest their own energy in order to lengthen their lives for wider
classes of application. Tackling these important issues requires a robust
architecture that takes into account the energy consumption level of functional
constituents and their interdependency. Without such architecture, it would be
difficult to formulate and optimize the overall energy consumption of a
wireless sensor network. Unlike most current researches that focus on a single
energy constituent of WSNs independent from and regardless of other
constituents, this paper presents an Energy Driven Architecture (EDA) as a new
architecture and indicates a novel approach for minimising the total energy
consumption of a WS
Load Balancing Techniques for Lifetime Maximizing in Wireless Sensor Networks
International audienceEnergy consumption has been the focus of many studies on Wireless Sensor Networks (WSN). It is well recognized that energy is a strictly limited resource in WSNs. This limitation constrains the operation of the sensor nodes and somehow compromises the long term network performance as well as network activities. Indeed, the purpose of all application scenarios is to have sensor nodes deployed, unattended, for several months or years.This paper presents the lifetime maximization problem in âmany-to-oneâ and âmostly-offâ wireless sensor networks. In such network pattern, all sensor nodes generate and send packets to a single sink via multi-hop transmissions. We noticed, in our previous experimental studies, that since the entire sensor data has to be forwarded to a base station via multi-hop routing, the traffic pattern is highly non-uniform, putting a high burden on the sensor nodes close to the base station.In this paper, we propose some strategies that balance the energy consumption of these nodes and ensure maximum network lifetime by balancing the traffic load as equally as possible. First, we formalize the network lifetime maximization problem then we derive an optimal load balancing solution. Subsequently, we propose a heuristic to approximate the optimal solution and we compare both optimal and heuristic solutions with most common strategies such as shortest-path and equiproportional routing. We conclude that through the results of this work, combining load balancing with transmission power control outperforms the traditional routing schemes in terms of network lifetime maximization
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