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The Spaces Between Us: Setting and Maintaining Boundaries in Wireless Spectrum Access
- PROCEEDINGS OF THE 16TH ANNUAL INTERNATIONAL CONFERENCE ON MOBILE COMPUTING AND NETWORKING (MOBICOM 2010)
, 2010
"... Guardbands are designed to insulate transmissions on adjacent frequencies from mutual interference. As more devices in a given area are packed into orthogonal wireless channels, choosing the right guardband size to minimize cross-channel interference becomes critical to network performance. Using bo ..."
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Guardbands are designed to insulate transmissions on adjacent frequencies from mutual interference. As more devices in a given area are packed into orthogonal wireless channels, choosing the right guardband size to minimize cross-channel interference becomes critical to network performance. Using both WiFi and GNU radio experiments, we show that the traditional “one-size-fits-all” approach to guardband assignment is ineffective, and can produce throughput degradation up to 80%. We find that ideal guardband values vary across different network configurations, and across different links in the same network. We argue that guardband values should be set based on network conditions and adapt to changes over time. We propose Ganache, an intelligent guardband configuration system that dynamically sets and adapts guardbands based on local topology and propagation conditions. Ganache includes three key mechanisms: an empirical model of guardband sizes based on power heterogeneity of adjacent links, network-wide frequency and guardband assignment, and local guardband adaptation triggered by realtime detection of cross-band interference. We deploy a Ganache prototype on a local 8-node GNU radio testbed. Detailed experiments on different topologies show that to minimize interference, traditional fixed-size configurations allocate more than 40 % of available spectrum to guardbands, while Ganache does the same using only 10 % of the spectrum, leading to a 150 % gain in throughput.
A survey on multichannel assignment protocols in wireless sensor networks
- IFIP Wireless Days, Niagara Falls
, 2011
"... Abstract—Micaz motes can communicate on multiple frequencies as specified in the 802.15.4 standard. This reality has given birth to multichannel communication paradigm in Wireless Sensor Networks (WSNs). Obviously, multichannel communication mitigates interferences, jamming and congestion, whereas i ..."
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Cited by 5 (2 self)
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Abstract—Micaz motes can communicate on multiple frequencies as specified in the 802.15.4 standard. This reality has given birth to multichannel communication paradigm in Wireless Sensor Networks (WSNs). Obviously, multichannel communication mitigates interferences, jamming and congestion, whereas it brings also challenging issues. Thus, in this paper, we are motivated to draw a picture of multichannel assignment protocols in WSNs. After having identified the reasons of resorting to multichannel communication paradigm in WSNs and the specific issues that should be tackled, we propose a classification of multichannel assignment protocols, pointing out different channel selection policies, channel assignment methods and channel coordination techniques. We conclude by a recapitulative table including many examples of existing multichannel protocols designed for WSNs. I.
CHANNEL ASSIGNMENT ALGORITHMS FOR MRMC WIRELESS MESH NETWORKS
"... ABSTRACT KEYWORDS Channel assignment, wireless multi-hop routing, multiple radios and multiple channels, wireless mesh networks, partially overlapping channels. ..."
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ABSTRACT KEYWORDS Channel assignment, wireless multi-hop routing, multiple radios and multiple channels, wireless mesh networks, partially overlapping channels.
Keywords: Adaptive Balanced control system Dynamic channel assignment
, 2012
"... Wireless mesh network the channel switch is not triggered even with overloaded data traffic and the link quality decreases significantly as the channel is overloaded. When the link capacity is under-estimated, the link is under-utilized. Moreover, when link traffic load increases from time to time, ..."
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Wireless mesh network the channel switch is not triggered even with overloaded data traffic and the link quality decreases significantly as the channel is overloaded. When the link capacity is under-estimated, the link is under-utilized. Moreover, when link traffic load increases from time to time, channel switch occurs frequently. Such frequent channel switches increase latency and degrade throughput, and can even cause network wide channel oscillations. In this paper, we propose a novel threshold-based control system, called balanced control system (BCS). The proposed threshold-based control policy consists of deciding, according to the real time traffic load and interference, whether to switch to another channel, which channel should be switched to and how to perform the switch. Our control model is based on a fuzzy logic control. The threshold which assists to make the channel switch decisions, could be deduced dynamically according to the real-time traffic of each node.We also design a novel dynamic channel assignment scheme,which is used for the selection of the new channel. The channel switch scheduler is provided to perform channel-switch processing for sender and receiver over enhanced routing protocols. We implement our system in NS2, and the simulation results show that with our proposed system, the performance improves by 12.3%–72.8 % in throughput and reduces 23.2%–52.3 % in latency. © 2012 Elsevier Inc. All rights reserved. 1.
PROTOCOL DESIGN IN WIRELESS NETWORKS: FEATURING CHANNEL ACCESS AND VEHICULAR COMMUNICATIONS
, 2012
"... Wireless Networks provide a very cost efficient solution for data connectivity over wide areas enabling ubiquitous computing environment through multi-hop relay. The scope of this dissertation encompasses two correlated domains of Wireless Network area, one is the Multi-Radio Multi-Channel Wireless ..."
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Wireless Networks provide a very cost efficient solution for data connectivity over wide areas enabling ubiquitous computing environment through multi-hop relay. The scope of this dissertation encompasses two correlated domains of Wireless Network area, one is the Multi-Radio Multi-Channel Wireless Mesh Network (MRMC-WMN) and the other is Vehicular Ad hoc Network (VANET). The research issues studied here are related to IEEE 802.11 based, multi-hop ad hoc wireless network. In the first part, we deal with some of the fundamental issues of Wireless Networks, with particular emphasis given on approaches and techniques for channel assignment and delay analysis in multi-radio multi-channel wireless mesh network. A novel channel assignment scheme has been proposed utilizing Partially Overlapped Channel (POC). We also introduced the notion of I-Matrix as a new interference model which takes into account one additional type of channel interference ignored by most researchers. Specifically, our interference model considers the effect of Self-Interference for multi-radio environment in addition to Adjacent Channel Interference(ACI) and Co-Channel Interference. We evaluate the performance of
