The art of computer programming, volume 1 (3rd ed.): fundamental algorithms
The art of computer programming, volume 1 (3rd ed.): fundamental algorithms
Diffusion approximations for storage processes in computer systems
SIGMETRICS '83 Proceedings of the 1983 ACM SIGMETRICS conference on Measurement and modeling of computer systems
NeXt generation/dynamic spectrum access/cognitive radio wireless networks: a survey
Computer Networks: The International Journal of Computer and Telecommunications Networking
Allocating dynamic time-spectrum blocks in cognitive radio networks
Proceedings of the 8th ACM international symposium on Mobile ad hoc networking and computing
CRAHNs: Cognitive radio ad hoc networks
Ad Hoc Networks
OFDM for cognitive radio: merits and challenges
IEEE Wireless Communications
Spectrum pooling: an innovative strategy for the enhancement of spectrum efficiency
IEEE Communications Magazine
Spectrum sensing in cognitive radio networks: requirements, challenges and design trade-offs
IEEE Communications Magazine
HC-MAC: A Hardware-Constrained Cognitive MAC for Efficient Spectrum Management
IEEE Journal on Selected Areas in Communications
Picasso: full duplex signal shaping to exploit fragmented spectrum
Proceedings of the 10th ACM Workshop on Hot Topics in Networks
Computer storage fragmentation: pioneering work of brian randell
Dependable and Historic Computing
A performance analysis of channel fragmentation in dynamic spectrum access systems
Queueing Systems: Theory and Applications
Picasso: flexible RF and spectrum slicing
Proceedings of the ACM SIGCOMM 2012 conference on Applications, technologies, architectures, and protocols for computer communication
Picasso: flexible RF and spectrum slicing
ACM SIGCOMM Computer Communication Review - Special october issue SIGCOMM '12
Review: Vulnerabilities in cognitive radio networks: A survey
Computer Communications
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Dynamic Spectrum Access systems exploit temporarily available spectrum ('white spaces') and can spread transmissions over a number of non-contiguous sub-channels. Such methods are highly beneficial in terms of spectrum utilization. However, excessive fragmentation degrades performance and hence off-sets the benefits. Thus, there is a need to study these processes so as to determine how to ensure acceptable levels of fragmentation. Hence, we present experimental and analytical results derived from a mathematical model. We model a system operating at capacity serving requests for bandwidth by assigning a collection of gaps (sub-channels) with no limitations on the fragment size. Our main theoretical result shows that even if fragments can be arbitrarily small, the system does not degrade with time. Namely, the average total number of fragments remains bounded. Within the very difficult class of dynamic fragmentation models (including models of storage fragmentation), this result appears to be the first of its kind. Extensive experimental results describe behavior, at times unexpected, of fragmentation under different algorithms. Our model also applies to dynamic linked-list storage allocation, and provides a novel analysis in that domain. We prove that, interestingly, the 50% rule of the classical (non-fragmented) allocation model carries over to our model. Overall, the paper provides insights into the potential behavior of practical fragmentation algorithms.