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Cognitive network

About: Cognitive network is a research topic. Over the lifetime, 4213 publications have been published within this topic receiving 107093 citations.


Papers
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Journal ArticleDOI
TL;DR: The results indicate that the network throughput increases significantly by increasing the number of transmitted packets of the secondary users and/or by allowing a small delay for the primary user packets.
Abstract: A cognitive network is considered that consists of a base station (BS) communicating with multiple primary and secondary users. Each secondary user can access only one of the orthogonal primary channels. A model is considered in which the primary users can tolerate a certain average delay. A special case is also considered in which the primary users do not suffer from any delay. A novel cross-layer scheme is proposed in which the BS performs successive interference cancellation and thus a secondary user can coexist with an active primary user without adversely affecting its transmission. A scheduling algorithm is proposed that minimizes the average packet delay of the secondary user under constraints on the average power transmitted by the secondary user and the average packet delay of the primary user. A resource allocation algorithm is also proposed to assign the secondary users' channels such that the total throughput of the network is maximized. Our results indicate that the network throughput increases significantly by increasing the number of transmitted packets of the secondary users and/or by allowing a small delay for the primary user packets.

30 citations

Journal ArticleDOI
TL;DR: A generic architecture for a cognitive node with a context driven approach which incorporates some formalisms including context spaces, ontology, process algebra to represent and manipulate various cognitive processes managing the cognitive node functionality is proposed.
Abstract: A cognitive radio (CR), in its generic form, needs to be highly flexible and adaptive while desirably hiding its complexities from users and system programmers. For the autonomic management the CR needs to be aware of the `self' and the `world' around it. Embedded intelligence with cognitive and collaborative adaptations require innovative techniques for managing the functionality of the device. Complexity of the cognitive processes involved demand for formal methods for run time evaluations and verification. In this paper we propose a generic architecture for a cognitive node with a context driven approach which incorporates some formalisms including context spaces, ontology, process algebra to represent and manipulate various cognitive processes managing the cognitive node functionality.

30 citations

Proceedings ArticleDOI
16 Jun 2008
TL;DR: This paper design and implement a cognitive wireless network system based on open documents of IEEE P1900.4, and evaluates its performance using UDP streaming and HTTP download to point out importance of higher layer coordination with lower layers for end-to-end performance improvements in cognitive wireless networks.
Abstract: IEEE P1900.4 is an emerging standard for optimized radio resource utilization where cognitive radio technologies are used for efficient spectrum utilization. In this paper, we design and implement a cognitive wireless network system based on open documents of IEEE P1900.4, and evaluate its performance using UDP streaming and HTTP download. Our experiments show interesting results that total network throughput in the HDP streaming is improved by 30% although some of individual terminals can not necessarily obtain better throughput. Also, it is shown that performance in the HTTP download becomes worse by up to about 40% as the number of handover increases due to the TCP window control. Our analysis is expected to point out importance of higher layer coordination with lower layers for end-to-end performance improvements in cognitive wireless networks.

30 citations

Journal IssueDOI
01 May 2009
TL;DR: Simulation results show that the proposed distributed cognitive radio MAC protocol can greatly reduce interference to the neighbor incumbent devices and lead to better protection of incumbent devices.
Abstract: The MAC protocol for a cognitive radio network should allow access to unused spectrum holes without (or with minimal) interference to incumbent system devices. To achieve this main goal, in this paper a distributed cognitive radio MAC (DCR-MAC) protocol is proposed for wireless ad hoc networks that provides for the detection and protection of incumbent systems around the communication pair. DCR-MAC operates over a separate common control channel and multiple data channels; hence, it is able to deal with dynamics of resource availability effectively in cognitive networks. A new type of hidden node problem is introduced that focuses on possible signal collisions between incumbent devices and cognitive radio ad hoc devices. To this end, a simple and efficient sensing information exchange mechanism between neighbor nodes with little overhead is proposed. In DCR-MAC, each ad hoc node maintains a channel status table with explicit and implicit channel sensing methods. Before a data transmission, to select an optimal data channel, a reactive neighbor information exchange is carried out. Simulation results show that the proposed distributed cognitive radio MAC protocol can greatly reduce interference to the neighbor incumbent devices. A higher number of neighbor nodes leads to better protection of incumbent devices. Copyright © 2008 John Wiley & Sons, Ltd.

30 citations

Proceedings ArticleDOI
12 May 2010
TL;DR: A comparative study of the different cognitive techniques applied to sensor network applications in recent times and evaluating their effectiveness in achieving the network's end-to-end goals is provided.
Abstract: Wireless Sensor Networks are believed to be the enabling technology for Ambient Intelligence. They hold the promise of delivering to a smart communication paradigm where applications evolve from user requirements. Cognitive agents capable of making proactive decisions based on learning, reasoning and information sharing when interspersed in sensor networks may help achieve end-to-end goals of the network, even in the presence of multiple constraints and optimization objectives. Cognitive radio at the physical layer of such agents might be able to enable the opportunistic use of the heterogeneous environment in which the sensor network is deployed. A framework used in Cognitive Networks that can be applied to application-specific sensor networks is discussed. The main contribution of this paper is providing a comparative study of the different cognitive techniques applied to sensor network applications in recent times, (including one by the authors) and evaluating their effectiveness in achieving the network's end-to-end goals.

30 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202317
202234
202175
2020104
2019121
2018134