Title
Practical conflict graphs for dynamic spectrum distribution
Abstract
Most spectrum distribution proposals today develop their allocation algorithms that use conflict graphs to capture interference relationships. The use of conflict graphs, however, is often questioned by the wireless community because of two issues. First, building conflict graphs requires significant overhead and hence generally does not scale to outdoor networks, and second, the resulting conflict graphs do not capture accumulative interference. In this paper, we use large-scale measurement data as ground truth to understand just how severe these issues are in practice, and whether they can be overcome. We build "practical" conflict graphs using measurement-calibrated propagation models, which remove the need for exhaustive signal measurements by interpolating signal strengths using calibrated models. These propagation models are imperfect, and we study the impact of their errors by tracing the impact on multiple steps in the process, from calibrating propagation models to predicting signal strength and building conflict graphs. At each step, we analyze the introduction, propagation and final impact of errors, by comparing each intermediate result to its ground truth counterpart generated from measurements. Our work produces several findings. Calibrated propagation models generate location-dependent prediction errors, ultimately producing conservative conflict graphs. While these "estimated conflict graphs" lose some spectrum utilization, their conservative nature improves reliability by reducing the impact of accumulative interference. Finally, we propose a graph augmentation technique that addresses any remaining accumulative interference, the last missing piece in a practical spectrum distribution system using measurement-calibrated conflict graphs.
Year
DOI
Venue
2013
10.1145/2465529.2465545
SIGMETRICS
Keywords
Field
DocType
accumulative interference,building conflict graph,resulting conflict graph,estimated conflict graph,dynamic spectrum distribution,conflict graph,conservative conflict graph,use conflict graph,measurement-calibrated conflict graph,practical conflict graph,calibrated propagation model,propagation model,interference
Graph,Imperfect,Wireless,Computer science,Interpolation,Theoretical computer science,Ground truth,Interference (wave propagation),Signal strength,Tracing
Conference
Volume
Issue
ISSN
41
1
0163-5999
Citations 
PageRank 
References 
28
0.95
33
Authors
6
Name
Order
Citations
PageRank
Xia Zhou1126470.59
Zengbin Zhang253627.05
Gang Wang346525.30
Xiaoxiao Yu4473.74
Ben Y. Zhao56274490.12
Haitao Zheng6107370.54