TY - JOUR
T1 - A characterization of delay performance of cognitive medium access
AU - Wang, Shanshan
AU - Zhang, Junshan
AU - Tong, Lang
N1 - Funding Information:
This research was supported in part by the National Science Foundation under grants CNS-0917087, CCF 1018115, DoD MURI project No. FA9550-09-1-0643, the Air Force Office of Scientific Research under STTR contracts FA9550-11-C-0006, and Science Foundation Arizona (SFAz). Part of this work was presented at IEEE INFOCOM 2010. Digital Object Identifier 10.1109/TWC.2012.010312.110765
PY - 2012/2
Y1 - 2012/2
N2 - We consider a cognitive radio network where multiple secondary users (SUs) contend for spectrum usage, using random access, over available primary user (PU) channels. Our focus is on SUs' queueing delay performance, for which a systematic understanding is lacking. We take a fluid queue approximation approach to study the steady-state delay performance of SUs, for cases with a single PU channel and multiple PU channels. Using stochastic fluid models, we represent the queue dynamics as Poisson driven stochastic differential equations, and characterize the moments of the SUs' queue lengths accordingly. Since in practical systems, an SU would have no knowledge of other users' activities, its contention probability has to be set based on local information. With this observation, we develop adaptive algorithms to find the optimal contention probability that minimizes the mean queue lengths. Moreover, we study the impact of multiple channels and multiple interfaces on SUs' delay performance. As expected, the use of multiple channels and/or multiple interfaces leads to significant delay reduction. Finally, we consider packet generation control to meet the delay requirements for SUs, and develop randomized and queue-length-based control mechanisms accordingly.
AB - We consider a cognitive radio network where multiple secondary users (SUs) contend for spectrum usage, using random access, over available primary user (PU) channels. Our focus is on SUs' queueing delay performance, for which a systematic understanding is lacking. We take a fluid queue approximation approach to study the steady-state delay performance of SUs, for cases with a single PU channel and multiple PU channels. Using stochastic fluid models, we represent the queue dynamics as Poisson driven stochastic differential equations, and characterize the moments of the SUs' queue lengths accordingly. Since in practical systems, an SU would have no knowledge of other users' activities, its contention probability has to be set based on local information. With this observation, we develop adaptive algorithms to find the optimal contention probability that minimizes the mean queue lengths. Moreover, we study the impact of multiple channels and multiple interfaces on SUs' delay performance. As expected, the use of multiple channels and/or multiple interfaces leads to significant delay reduction. Finally, we consider packet generation control to meet the delay requirements for SUs, and develop randomized and queue-length-based control mechanisms accordingly.
KW - Delay analysis
KW - cognitive radio networks
KW - fluid approximation
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U2 - 10.1109/TWC.2012.010312.110765
DO - 10.1109/TWC.2012.010312.110765
M3 - Article
AN - SCOPUS:84857367707
SN - 1536-1276
VL - 11
SP - 800
EP - 809
JO - IEEE Transactions on Wireless Communications
JF - IEEE Transactions on Wireless Communications
IS - 2
M1 - 6123781
ER -