700,441 research outputs found
A Communication Monitor for Wireless Sensor Networks Based on Software Defined Radio
Link quality estimation of reliability-crucial wireless sensor networks (WSNs) is often limited by the observability and testability of single-chip radio transceivers. The estimation is often based on collection of packer-level statistics, including packet reception rate, or vendor-specific registers, such as CC2420's Received Signal Strength Indicator (RSSI) and Link Quality Indicator (LQI). The speed or accuracy of such metrics limits the performance of reliability mechanisms built in wireless sensor networks. To improve link quality estimation in WSNs, we designed a powerful wireless communication monitor based on Software Defined Radio (SDR). We studied the relations between three implemented link quality metrics and packet reception rate under different channel conditions. Based on a comparison of the metrics' relative advantages, we proposed using a combination of them for fast and accurate estimation of a sensor network link
Denial of service attacks and challenges in broadband wireless networks
Broadband wireless networks are providing internet and related services to end users. The three most important broadband wireless technologies are IEEE 802.11, IEEE 802.16, and
Wireless Mesh Network (WMN). Security attacks and
vulnerabilities vary amongst these broadband wireless networks because of differences in topologies, network operations and physical setups. Amongst the various security risks, Denial of Service (DoS) attack is the most severe security threat, as DoS can compromise the availability and integrity of broadband
wireless network. In this paper, we present DoS attack issues in broadband wireless networks, along with possible defenses and future directions
Matching Theory for Future Wireless Networks: Fundamentals and Applications
The emergence of novel wireless networking paradigms such as small cell and
cognitive radio networks has forever transformed the way in which wireless
systems are operated. In particular, the need for self-organizing solutions to
manage the scarce spectral resources has become a prevalent theme in many
emerging wireless systems. In this paper, the first comprehensive tutorial on
the use of matching theory, a Nobelprize winning framework, for resource
management in wireless networks is developed. To cater for the unique features
of emerging wireless networks, a novel, wireless-oriented classification of
matching theory is proposed. Then, the key solution concepts and algorithmic
implementations of this framework are exposed. Then, the developed concepts are
applied in three important wireless networking areas in order to demonstrate
the usefulness of this analytical tool. Results show how matching theory can
effectively improve the performance of resource allocation in all three
applications discussed
Spatial Throughput Maximization of Wireless Powered Communication Networks
Wireless charging is a promising way to power wireless nodes' transmissions.
This paper considers new dual-function access points (APs) which are able to
support the energy/information transmission to/from wireless nodes. We focus on
a large-scale wireless powered communication network (WPCN), and use stochastic
geometry to analyze the wireless nodes' performance tradeoff between energy
harvesting and information transmission. We study two cases with battery-free
and battery-deployed wireless nodes. For both cases, we consider a
harvest-then-transmit protocol by partitioning each time frame into a downlink
(DL) phase for energy transfer, and an uplink (UL) phase for information
transfer. By jointly optimizing frame partition between the two phases and the
wireless nodes' transmit power, we maximize the wireless nodes' spatial
throughput subject to a successful information transmission probability
constraint. For the battery-free case, we show that the wireless nodes prefer
to choose small transmit power to obtain large transmission opportunity. For
the battery-deployed case, we first study an ideal infinite-capacity battery
scenario for wireless nodes, and show that the optimal charging design is not
unique, due to the sufficient energy stored in the battery. We then extend to
the practical finite-capacity battery scenario. Although the exact performance
is difficult to be obtained analytically, it is shown to be upper and lower
bounded by those in the infinite-capacity battery scenario and the battery-free
case, respectively. Finally, we provide numerical results to corroborate our
study.Comment: 15 double-column pages, 8 figures, to appear in IEEE JSAC in February
2015, special issue on wireless communications powered by energy harvesting
and wireless energy transfe
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