Multi-User Opportunistic Spectrum Access Using Reinforcement Learning

2014 ◽  
Vol 926-930 ◽  
pp. 2357-2361
Author(s):  
Cheng Long Xu ◽  
Yun Peng Cheng ◽  
Yang Chen ◽  
Cheng Meng Ren ◽  
Heng Yang

This paper studies the channel exploration problem for the distributed opportunistic spectrum access (D-OSA) system, where multiple secondary users (SUs) sequentially sense multiple licensed channels and utilize one of idle channel. However, channel sensing order can affect the system performance seriously. When using a better sensing order, the SU can find faster a free channel with high quality and the less collisions among SUs can happen. In this paper, we propose a mechanism using reinforcement learning to find dynamically out a sensing order for improving the system performance. In the proposed mechanism, the interactions among SUs are considered. Simulation results are provided to show the effectiveness of the proposed mechanism and the significant improvement of the system performance.

2014 ◽  
Vol 926-930 ◽  
pp. 2867-2870
Author(s):  
Yu Meng Wang ◽  
Liang Shen ◽  
Xiang Gao ◽  
Cheng Long Xu ◽  
Xiao Ya Li ◽  
...  

This paper studies the problem of distributed multiuser Opportunistic Spectrum Access based on Partially Observable Markov Decision Process (POMDP). Due to the similarity of spectrum environment, secondary users may choose the same channel adopting their own single user approach, which leads to collision. Referring to the previous works, we propose a more flexible and adaptive policy named “threshold-deciding”. Firstly, the SU gets a channel by adopting the random policy. Secondly, the SU decides whether to sense the channel by comparing the available probability with the given threshold. The policy not only decreases the collisions among SUs but also reduces the consumption of time and energy. The simulation results shows that the upgrade of performance is up to 100% compared with the existing random policy, which demonstrate the advantage of the proposed policy.


2016 ◽  
Vol 8 (2) ◽  
pp. 94-110
Author(s):  
Danda B. Rawat ◽  
Sachin Shetty

Opportunistic Spectrum Access (OSA) in a Cognitive Radio Network (CRN) is regarded as emerging technology for utilizing the scarce Radio Frequency (RF) spectrum by allowing unlicensed secondary users (SUs) to access licensed spectrum without creating harmful interference to primary users (PUs). The SUs are considerably constrained by their limited power, memory and computational capacity when they have to make decision about spectrum sensing for wide band regime and OSA. The SUs in CRN have the potential to mitigate these constraints by leveraging the vast storage and computational capacity of cloud computing approaches. In this paper, the authors investigate a game theoretic approach for opportunistic spectrum access in cognitive networks. The proposed algorithm leverages the geo-locations of both SUs and spectrum opportunities to facilitate OSA to SUs. The active SUs using game theory adapt their transmit powers in a distributed manner based on the estimated average packet-error rate while satisfying the Quality-of-Service (QoS) in terms of signal-to-interference-noise-ratio (SINR). Furthermore, to control greedy SUs in distributed power control game, the authors introduce a manager/leader through a Stackelberg power adaptation game. The performance of the proposed approaches is investigated using numerical results obtained from simulations.


2020 ◽  
Vol 68 ◽  
pp. 2613-2628
Author(s):  
Zun Yan ◽  
Peng Cheng ◽  
Zhuo Chen ◽  
Yonghui Li ◽  
Branka Vucetic

Author(s):  
Krešimir Dabcevic ◽  
Lucio Marcenaro ◽  
Carlo S. Regazzoni

While potentially solving the spectrum underutilization problem using methods such as dynamic and opportunistic spectrum access, Cognitive Radios (CRs) also bring a set of security issues and potential breaches that have to be addressed. These issues come from the two important capabilities implemented within CRs: their cognition ability and reconfigurability. This chapter focuses on identifying, presenting, and classifying the main potential security attacks and vulnerabilities, as well as proposing appropriate counter-measures and solutions for them. These are supplemented by simulation results and metrics, with the intention of estimating the efficiency of each of the observed attacks and its counter-measure. The presented simulations are performed in the proprietary C/C++ and Matlab/Simulink simulators. nSHIELD is a major ongoing European embedded systems security-related project, which is used to demonstrate the practicability of the potential implementation of the proposed countermeasures and solutions for the discussed security problems and issues.


Author(s):  
Andre C. Mendes ◽  
Carlos Henrique P. Augusto ◽  
Marcel W. R. da Silva ◽  
Raphael M. Guedes ◽  
Jose F. de Rezende

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