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Advances in Cognitive Radio Networks: A Survey
- IEEE JOURNAL OF SELECTED TOPICS IN SIGNAL PROCESSING
, 2011
"... With the rapid deployment of new wireless devices and applications, the last decade has witnessed a growing demand for wireless radio spectrum. However, the fixed spectrum assignment policy becomes a bottleneck for more efficient spectrum utilization, under which a great portion of the licensed spe ..."
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With the rapid deployment of new wireless devices and applications, the last decade has witnessed a growing demand for wireless radio spectrum. However, the fixed spectrum assignment policy becomes a bottleneck for more efficient spectrum utilization, under which a great portion of the licensed spectrum is severely under-utilized. The inefficient usage of the limited spectrum resources urges the spectrum regulatory bodies to review their policy and start to seek for innovative communication technology that can exploit the wireless spectrum in a more intelligent and flexible way. The concept of cognitive radio is proposed to address the issue of spectrum efficiency and has been receiving an increasing attention in recent years, since it equips wireless users the capability to optimally adapt their operating parameters according to the interactions with the surrounding radio environment. There have been many significant developments in the past few years on cognitive radios. This paper surveys recent advances in research related to cognitive radios. The fundamentals of cognitive radio technology, architecture of a cognitive radio network and its applications are first introduced. The existing works in spectrum sensing are reviewed, and important issues in dynamic spectrum allocation and sharing are investigated in detail.
An Implementation of Cognitive Resource Management on LTE Platform
"... Abstract—In this paper we describe an LTE based demon-strator of the Universal Link Layer API (ULLA) and Cogni-tive Resource Manager (CRM) modules that are developed in ARAGORN project. The demonstrated LTE system comprises one LTE TDD eNode B and one User Equipment (UE). We first introduce ULLA and ..."
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Abstract—In this paper we describe an LTE based demon-strator of the Universal Link Layer API (ULLA) and Cogni-tive Resource Manager (CRM) modules that are developed in ARAGORN project. The demonstrated LTE system comprises one LTE TDD eNode B and one User Equipment (UE). We first introduce ULLA and CRM framework and then demon-strate their suitability to be implemented with the existing LTE equipments. We show how, through ULLA, CRM is able to obtain PHY/MAC status information of the link between the eNode B and UE, and in turn change system parameters to achieve better resource utilization and transmission efficiency. The control logic can be implemented with simple adaptation or policy-based intelligent methods. The platform clearly shows the feasibility to use ULLA/CRM architecture for radio resource management in a LTE network. It also shows the neutrality of ULLA/CRM mechanisms towards PHY/MAC characteristics of LTE technology platform; hence the platform is viable to flexibly switch between technology platforms (e.g. between LTE access and WiFi access) under the control of ULLA/CRM. I.
Review Cognitive radio technology: From distributed spectrum coordination to adaptive network collaborationI
, 2008
"... This paper presents an integrated view of cognitive radio technologies for efficient wireless services in dense spectrum environments. The rationale for cognitive radio based systems is discussed, leading to an identification of the available design space that ranges from reactive interference avoid ..."
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This paper presents an integrated view of cognitive radio technologies for efficient wireless services in dense spectrum environments. The rationale for cognitive radio based systems is discussed, leading to an identification of the available design space that ranges from reactive interference avoidance to spectrum etiquette and eventually network collaboration. After reviewing prior work in the dynamic spectrum area, a specific distributed spectrum etiquette protocol called “common spectrum coordination channel (CSCC) ” is introduced. Performance gains achieved with CSCC relative to simpler reactive time/frequency/power control algorithms are evaluated for example in WiFi/Bluetooth and WiFi/WiMax co-existence scenarios. The next level of system performance can be achieved through opportunistic collaboration between radios to form ad hoc multi-hop networks in which neighboring nodes associate with each other at high bit-rate and low power. Adaptive wireless networks of this type will require new protocol architectures which integrate flexible PHY/MAC and cross-layer capabilities with ad hoc network discovery and multi-hop routing. A specific “CogNet ” protocol architecture based on the concept of a “global control plane (GCP) ” is described. Major CogNet protocol modules for bootstrapping, discovery, data path setup and naming/addressing are outlined, and representative ns-2 simulation results are provided for validation. In conclusion, the paper gives a preview of the network-centric WiNC2R prototype under development at WINLAB as an experimental cognitive radio platform.
Collaborative approaches to probabilistic . . .
, 2014
"... Tactical networks, networks designed to facilitate command and control capabilities for militaries, have key attributes that differ from the Internet. Characterizing, modeling, and exploiting our understanding of these differences is the focus of this research. The differences between tactical and c ..."
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Tactical networks, networks designed to facilitate command and control capabilities for militaries, have key attributes that differ from the Internet. Characterizing, modeling, and exploiting our understanding of these differences is the focus of this research. The differences between tactical and commercial networks can be found primarily in the areas of access bandwidth, access diversity, access latency, core latency, subnet distribution, and network infrastructure. In this work we characterize and model these differences. These attributes affect research into issues such as overlays, service discovery, and server selection among others, as well as the deployment of services and systems in tactical networks. Researchers traditionally struggle with measuring, analyzing, or testing new ideas on tactical networks due to a lack of direct access, and thus this characterization is crucial to evolving this research field. In this work we develop a topology generator that creates realistic tactical networks that can be visualized, analyzed, and emulated. Topological features including geographically constrained line of sight networks, high density low bandwidth satellite networks, and the latest high bandwidth on-the-move networks are captured. All of these topological features can be mixed to create realistic networks for many different tactical scenarios. A web based visualization tool is developed, as well as the ability to export topologies to the Mininet network virtualization environment. Finally, state-of-the-art server selection algorithms are reviewed and found to perform poorly for tactical networks. We develop a collaborative algorithm tailored to the attributes of tactical networks, and utilize our generated networks to assess the algorithm, finding a reduction in utilized bandwidth and a significant reduction in client to server latency as key improvements.
INVITED PAPER Cognitive Radio and Networking
, 2008
"... A large research team with a wide range of expertiseVfrom ICs and reconfigurable computingtowirelessnetworkingVworkstoachievethepromiseofcognitiveradio. ..."
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A large research team with a wide range of expertiseVfrom ICs and reconfigurable computingtowirelessnetworkingVworkstoachievethepromiseofcognitiveradio.
Cognitive Radio Systems: State of the art
"... Cognitive radio has been introduced by Mitola in 1999 as an extension to software radio [1] (Stevens USA). Cognitive radio extends the software radio with radio-domain model-based reasoning about etiquettes (set of RF bands, air interfaces, protocols, and spatial and temporal patterns that moderate ..."
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Cognitive radio has been introduced by Mitola in 1999 as an extension to software radio [1] (Stevens USA). Cognitive radio extends the software radio with radio-domain model-based reasoning about etiquettes (set of RF bands, air interfaces, protocols, and spatial and temporal patterns that moderate the use of the radio spectrum). Cognitive radio enhances the flexibility of personal services through a Radio Knowledge Representation Language (RKRL). This language represents knowledge of radio etiquette, devices, software modules, propagation, networks, user needs, and application scenarios in a way that supports automated reasoning about the needs of the user. This empowers software radios to conduct expressive negotiations among peers about the use of radio spectrum across fluents of space, time, and user context. With RKRL, cognitive radio agents may actively manipulate the protocol stack to adapt known etiquettes to better satisfy the user’s needs. This transforms radio nodes from blind executors of predefined protocols to radio-domain-aware intelligent agents that search out ways to deliver the services the user wants even if that user does
Executive Summary
, 2009
"... Wireless technology is proliferating rapidly, and the vision of pervasive wireless computing and communications offers the promise of many societal and individual benefits. While consumer devices such as cell phones, PDAs and laptops receive a lot of attention, the impact of wireless technology is m ..."
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Wireless technology is proliferating rapidly, and the vision of pervasive wireless computing and communications offers the promise of many societal and individual benefits. While consumer devices such as cell phones, PDAs and laptops receive a lot of attention, the impact of wireless technology is much broader, e.g., through sensor networks for safety applications and home automation, smart grid control, medical wearable and embedded wireless devices, and entertainment systems. This explosion of wireless applications creates an ever-increasing demand for more radio spectrum. However, most easily usable spectrum bands have been allocated, although many studies have shown that these bands are significantly underutilized. These considerations have motivated the search for breakthrough radio technologies that can scale to meet future demands both in terms of spectrum efficiency and application performance. Cognitive radios offer the promise of being a disruptive technology innovation that will enable the future wireless world. Cognitive radios are fully programmable wireless devices that can sense their environment and dynamically adapt their transmission waveform, channel access method, spectrum use, and networking protocols as needed for good network and application performance. We anticipate that cognitive radio technology will soon emerge from early stage laboratory trials and vertical applications to
2Cognitive Networks1
"... Current data networking technology limits a network’s ability to adapt, of-ten resulting in sub-optimal performance. Limited in state, scope, and re-sponse mechanisms, the network elements (consisting of nodes, protocol layers, policies, and behaviors) are unable to make intelligent adaptations. Com ..."
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Current data networking technology limits a network’s ability to adapt, of-ten resulting in sub-optimal performance. Limited in state, scope, and re-sponse mechanisms, the network elements (consisting of nodes, protocol layers, policies, and behaviors) are unable to make intelligent adaptations. Communi-
