On calculating connected dominating set for efficient routing in ad hoc wireless networks
DIALM '99 Proceedings of the 3rd international workshop on Discrete algorithms and methods for mobile computing and communications
A minimum spanning tree algorithm with inverse-Ackermann type complexity
Journal of the ACM (JACM)
Centralized channel assignment and routing algorithms for multi-channel wireless mesh networks
ACM SIGMOBILE Mobile Computing and Communications Review
NeXt generation/dynamic spectrum access/cognitive radio wireless networks: a survey
Computer Networks: The International Journal of Computer and Telecommunications Networking
Efficient Discovery of Spectrum Opportunities with MAC-Layer Sensing in Cognitive Radio Networks
IEEE Transactions on Mobile Computing
Graph Theory
Optimal selection of channel sensing order in cognitive radio
IEEE Transactions on Wireless Communications
Modeling and analysis for proactive-decision spectrum handoff in cognitive radio networks
ICC'09 Proceedings of the 2009 IEEE international conference on Communications
Optimal spectrum sensing framework for cognitive radio networks
IEEE Transactions on Wireless Communications
Leveraging the Algebraic Connectivity of a Cognitive Network for Routing Design
IEEE Transactions on Mobile Computing
Decentralized cognitive MAC for opportunistic spectrum access in ad hoc networks: A POMDP framework
IEEE Journal on Selected Areas in Communications
HC-MAC: A Hardware-Constrained Cognitive MAC for Efficient Spectrum Management
IEEE Journal on Selected Areas in Communications
On the Connectivity and Multihop Delay of Ad Hoc Cognitive Radio Networks
IEEE Journal on Selected Areas in Communications
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In cognitive networks, spectrum handoff occurs when primary users reclaim their rights to access their licensed spectrum. When links perform spectrum handoff, their communication may be interrupted for a certain period and incurs spectrum handoff delay. Existing work only considered the problem of minimizing spectrum handoff delay of a single link in single-hop cognitive networks, referred to as the SH-SLSH problem. This paper studies a more challenging problem (referred to as the SH-MLMH problem) in which multiple links perform spectrum handoff in multi-hop cognitive networks. Assuming each node is equipped with multiple radios and multi-path routing is adopted, the SH-MLMH problem targets at maintaining the network connectivity and minimizing the Total Handoff Completion Time (THCT) by coordinating multiple links to perform spectrum handoff. THCT is defined as the time for all links to finish spectrum handoff. We can keep the communication of switching links uninterrupted by maintaining network connectivity and adopting multi-path routing. To the best of our knowledge, we are the first to study the SH-MLMH problem. We make following contributions in this paper. We prove that the SH-MLMH problem is NP-hard. We propose both centralized and distributed algorithm to solve the SH-MLMH problem. We prove that the centralized algorithm can achieve a logarithmic approximation ratio. The simulation results show that our proposed algorithms not only improve the network throughput but also reduce THCT compared with spectrum handoff without coordination.