Comprehensive survey on quality of service provisioning approaches in cognitive radio networks : part one

Much interest in Cognitive Radio Networks (CRNs) has been raised recently by enabling unlicensed (secondary) users to utilize the unused portions of the licensed spectrum. CRN utilization of residual spectrum bands of Primary (licensed) Networks (PNs) must avoid harmful interference to the users of PNs and other overlapping CRNs. The coexisting of CRNs depends on four components: Spectrum Sensing, Spectrum Decision, Spectrum Sharing, and Spectrum Mobility. Various approaches have been proposed to improve Quality of Service (QoS) provisioning in CRNs within fluctuating spectrum availability. However, CRN implementation poses many technical challenges due to a sporadic usage of licensed spectrum bands, which will be increased after deploying CRNs. Unlike traditional surveys of CRNs, this paper addresses QoS provisioning approaches of CRN components and provides an up-to-date comprehensive survey of the recent improvement in these approaches. Major features of the open research challenges of each approach are investigated. Due to the extensive nature of the topic, this paper is the first part of the survey which investigates QoS approaches on spectrum sensing and decision components respectively. The remaining approaches of spectrum sharing and mobility components will be investigated in the next part

Dynamic adaptation of delayed time of diffusion of emergency messages in cognitive vehicular networks

[ES] En este artículo se presenta un protocolo de difusión de mensajes de seguridad para emergencia que utiliza una adaptación dinámica del tiempo de retraso en el entorno de una red vehicular cognitiva. El escenario que se estudia considera la compartición del espectro entre la banda para comunicaciones vehiculares y la banda de la televisión digital con el objetivo de mitigar los efectos de la tormenta de difusión en una red vehicular. Dos de las técnicas de mitigación de la tormenta de difusión más utilizadas en la literatura son comparadas contra el protocolo propuesto en términos de las probabilidades de accesibilidad de los mensajes de emergencia y de la ocupación del canal. Los resultados numéricos muestran que el protocolo con la adaptación dinámica del tiempo presenta un mejor desempeño en condiciones de alta densidad de vehículos, lo cual es característico de un escenario de tormenta de difusión.[EN] This article presents a protocol for the dissemination of emergency safety messages that uses a dynamic adaptation of the delay time in the environment of a cognitive vehicular network. The scenario studied considers the spectrum sharing between the band for vehicular communications and the digital television band with the objective of mitigating the effects of the diffusion storm on a vehicular network. Two of the most commonly used diffusion mitigation techniques in the literature are compared against the proposed protocol in terms of the probabilities of reachability of emergency messages and channel occupancy. The numerical results show that the protocol with the dynamic adaptation of the time presents a better performance in conditions of high density of vehicles, which is characteristic of a diffusion storm scenario.El presente trabajo de investigación ha sido parcialmente financiado por el Consejo Nacional de Ciencia y Tecnología ( CONACYT) de México a través de la Beca Nacional para Estudios de Posgrado no. 445821.Avalos Gómez, JU.; Stevens-Navarro, E.; Pineda-Rico, U.; Cárdenas-Juárez, M.; Arce, A.; González, S. (2020). Adaptación dinámica del tiempo de retraso de difusión de mensajes de emergencia en redes vehiculares cognitivas. Revista Iberoamericana de Automática e Informática industrial. 17(3). https://doi.org/10.4995/riai.2019.12067OJS284173Avalos Gómez, J. U., Pineda-Rico, U., Cardenas-Juarez, M., Garcia- Barrientos, A., Arce, A., Stevens-Navarro, E., nov 2018. Broadcast storm mitigation of esms using spectrum sharing in cognitive radio vanets. In: 2018 International Conference on Mechatronics, Electronics and Automotive Engineering (ICMEAE). pp. 102-107. https://doi.org/10.1109/ICMEAE.2018.00026Bechler, M., Horozovic, A., Kastner, R., 2015. Evaluation of car-2-x scenarios for automated driving. In: FAST-zero'15: 3rd International Symposium on Future Active Safety Technology Toward zero traffic accidents. pp. 397-402.Bi, Y., Shan, H., Shen, X. S., Wang, N., Zhao, H., mar 2016. A multi-hop broadcast protocol for emergency message dissemination in urban vehicular ad hoc networks. IEEE Transactions on Intelligent Transportation Systems 17 (3), 736-750. https://doi.org/10.1109/TITS.2015.2481486Feukeu, E. A., Zuva, T., dec 2017. Overcoming broadcast storm problem in a vehicular network. In: 2017 13th International Conference on Signal-Image Technology Internet-Based Systems (SITIS). pp. 402-407. https://doi.org/10.1109/SITIS.2017.72IEEE802.11p, jul 2010. Ieee standard for information technology- local and metropolitan area networks- specific requirements- part 11: Wireless lan medium access control (mac) and physical layer (phy) specifications amendment 6: Wireless access in vehicular environments. IEEE Std 802.11p-2010 (Amendment to IEEE Std 802.11-2007 as amended by IEEE Std 802.11k-2008, IEEE Std 802.11r-2008, IEEE Std 802.11y-2008, IEEE Std 802.11n-2009, and IEEE Std 802.11w-2009), 1-51. https://doi.org/10.1109/IEEESTD.2010.5514475Khattab, A., Bayoumi, M. A., may 2015a. An overview of ieee standardization efforts for cognitive radio networks. In: 2015 IEEE International Symposium on Circuits and Systems (ISCAS). pp.982-985. https://doi.org/10.1109/ISCAS.2015.7168800Khattab, A., Bayoumi, M. A., dec 2015b. Standardization of cognitive radio networking: a comprehensive survey. annals of telecommunications - annales des télécommunications 70 (11), 465-477. https://doi.org/10.1007/s12243-015-0468-5Korkmaz, G., Ekici, E., Özgüner, F., jun 2006. An efficient fully ad-hoc multi-hop broadcast protocol for inter-vehicular communication systems. In: 2006 IEEE International Conference on Communications. Vol. 1. pp. 423-428. https://doi.org/10.1109/ICC.2006.254764Korkmaz, G., Ekici, E., Özgüner, F., Özgüner, U., 2004. Urban Multihop broadcast protocol for inter-vehicle communication systems. In: Proceedings of the 1st ACM International Workshop on Vehicular Ad Hoc Networks. VANET '04. ACM, New York, NY, USA, pp. 76-85. https://doi.org/10.1145/1023875.1023887Lim, J., Kim, W., Naito, K., Yun, J., Cabric, D., Gerla, M., nov 2014. Interplay between tvws and dsrc: Optimal strategy for safety message dissemination in vanet. IEEE Journal on Selected Areas in Communications 32 (11), 2117-2133. https://doi.org/10.1109/JSAC.2014.1411RP02Pagadarai, S., Lessard, B. A., Wyglinski, A. M., Vuyyuru, R., Altintas, O., 2013. Vehicular communications, enhanced networking through dynamic spectrum access. IEEE Vehicular Technology Magazine 8, 93-103. https://doi.org/10.1109/MVT.2013.2268659Sahoo, J., Wu, E. H., Sahu, P. K., Gerla, M., sep 2011. Binarypartition-assisted mac-layer broadcast for emergency message dissemination in vanets. IEEE Transactions on Intelligent Transportation Systems 12 (3), 757-770. https://doi.org/10.1109/TITS.2011.2159003Singh, K. D., Rawat, P., Bonnin, J. M., 2014. Cognitive radio for vehicular ad hoc networks (cr-vanets): Approaches and challenges. EURASIP Journal on Wireless Communications and Networking 2014, 49. https://doi.org/10.1186/1687-1499-2014-49Sum, C., Villardi, G. P., Rahman, M. A., Baykas, T., Tran, H. N., Lan, Z., Sun, C., Alemseged, Y., Wang, J., Song, C., Pyo, C., Filin, S., Harada, H., jul 2013. Cognitive communication in tv white spaces: An overview of regulations, standards, and technology [accepted from open call]. IEEE Communications Magazine 51 (7), 138-145. https://doi.org/10.1109/MCOM.2013.6553690Suthaputchakun, C., Dianati, M., Sun, Z., jul 2014. Trinary partitioned black-burst-based broadcast protocol for time-critical emergency message dissemination in vanets. IEEE Transactions on Vehicular Technology 63 (6), 2926-2940. https://doi.org/10.1109/TVT.2013.2293020Tsukamoto, K., Oie, Y., Kremo, H., Altintas, O., Tanaka, H., Fujii, T., apr 2015. Implementation and performance evaluation of distributed autonomous multi-hop vehicle-to-vehicle communications over tv white space. Mobile Networks and Applications 20 (2), 203-219. DOI: https://doi.org/10.1007/s11036-015-0576-5Wisitpongphan, N., Tonguz, O. K., Parikh, J. S., Mudalige, P., Bai, F., Sadekar, V., dec 2007. Broadcast storm mitigation techniques in vehicular ad hoc networks. IEEE Wireless Communications 14 (6), 84-94. https://doi.org/10.1109/MWC.2007.4407231Wu, L., Nie, L., Fan, J., He, Y., Liu, Q., Wu, D., 2017. An efficient multi-hop broadcast protocol for emergency messages dissemination in vanets. Chinese Journal of Electronics 26 (3), 614-623. https://doi.org/10.1049/cje.2017.03.00

Cognitive radio networks : quality of service considerations and enhancements

The explosive growth of wireless and mobile networks, such as the Internet of Things and 5G, has led to a massive number of devices that primarily use wireless channels within a limited range of the radio frequency spectrum (RFS). The use of RFS is heavily regulated, both nationally and internationally, and is divided into licensed and unlicensed bands. While many of the licensed wireless bands are underutilised, useable unlicensed bands are usually overcrowded, making the efficient use of RFS one of the critical challenges faced by future wireless communication technologies. The cognitive radio (CR) concept is proposed as a promising solution for the underutilisation of useful RFS bands. Fundamentally, CR technology is based on determining the unoccupied licensed RFS bands, called spectrum white spaces or holes, and accessing them to achieve better RFS utilisation and transmission propagation. The holes are the frequencies unused by the licensed user, or primary user (PU). Based on spectrum sensing, a CR node, or secondary user (SU), senses the surrounding spectrum periodically to detect any potential PU transmission in the current channel and to identify the available spectrum holes. Under current RFS regulations, SUs may use spectrum holes as long as their transmissions do not interfere with those of the PU. However, effective spectrum sensing can introduce overheads to a CR node operation. Such overheads affect the quality of service (QoS) of the running applications. Reducing the sensing impact on the QoS is one of the key challenges to adopting CR technology, and more studies of QoS issues related to implementing CR features are needed. This thesis aims to address these QoS issues in CR while considered the enhancement of RFS utilisation. This study concentrates on the spectrum sensing function, among other CR functions, because of its major impact on QoS and spectrum utilisation. Several spectrum sensing methods are reviewed to identify potential research gaps in analysing and addressing related QoS implications. It has been found that none of the well-known sensing techniques is suitable for all the diverse QoS requirements and RFS conditions: in fact, higher accuracy sensing methods cause a significant QoS degradation, as illustrated by several simulations in this work. For instance, QoS degradation caused by high-accuracy sensing has not yet been addressed in the IEEE 802.11e QoS mechanism used in the proposed CR standard, IEEE 802.11af (or White-Fi). This study finds that most of the strategies proposed to conduct sensing are based on a fixed sensing method that is not adaptable to the changeable nature of QoS requirements. In contrast, this work confirms the necessity of using various sensing techniques and parameters during a CR node operation for better performance

Wideband Spectrum Sensing for Dynamic Spectrum Sharing

The proliferation of wireless devices grows exponentially, demanding more and more data communication capacity over wireless links. Radio spectrum is a scarce resource, and traditional wireless networks deployed by Mobile Network Operators (MNO) are based on an exclusive spectrum band allocation. However, underutilization of some licensed bands in time and geographic domains has been reported, especially in rural areas or areas away from high population density zones. This coexistence of increasingly high data communication needs and spectrum underutilization is an incomprehensible scenario. A more rational and efficient use of the spectrum is the possibility of Licensed Users (known as Primary Users – PU) to lease the spectrum, when not in use, to Unlicensed Users (known as Secondary Users – SU), or allowing the SU to opportunistically use the spectrum after sensing and verifying that the PU is idle. In this latter case, the SU must stop transmitting when the PU becomes active. This thesis addresses the spectrum sensing task, which is essential to provide dynamic spectrum sharing between PUs and SUs. We show that the Spectral Correlation Function (SCF) and the Spectral Coherence Function (SCoF) can provide a robust signal detection algorithm by exploiting the cyclostationary characteristics of the data communication signal. We enhance the most used algorithm to compute de SCF - the FAM (FFT Accumulation Method) algorithm – to efficiently compute the SCF in a local/zoomed region of the support ( ; ) plane (frequency/cycle frequency plane). This will provide the quick identification of spectral bands in use by PUs or free, in a wideband sampling scenario. Further, the characterization of the probability density of the estimates of the SCF and SCoF when only noise is present, using the FAM algorithm, will allow the definition of an adaptive threshold to develop a blind (with respect to the noise statistics) Constant False Alarm Rate (CFAR) detector (using the SCoF) and also a CFAR and a Constant Detection Rate (CDR) detector when that characterization is used to obtain an estimate of the background noise variance (using the SCF).A proliferação de dispositivos sem fios cresce de forma exponencial, exigindo cada vez mais capacidade de comunicação de dados através de ligações sem fios. O espectro radioelétrico é um recurso escasso, e as redes sem fios tradicionais implantadas pelos Operadores de Redes Móveis baseiam-se numa atribuição exclusiva de bandas do espectro. No entanto, tem sido relatada a subutilização de algumas bandas licenciadas quer ao longo do tempo, quer na sua localização geográfica, especialmente em áreas rurais, e em áreas longe de zonas de elevada densidade populacional. A coexistência da necessidade cada vez maior de comunicação de dados, e a subutilização do espectro é um cenário incompreensível. Uma utilização mais racional e eficiente do espectro pressupõe a possibilidade dos Utilizadores Licenciados (conhecidos como Utilizadores Primários – Primary Users - PU) alugarem o espectro, quando este não está a ser utilizado, a Utilizadores Não Licenciados (conhecidos como Utilizadores Secundários – Secondary Users - SU), ou permitir ao SU utilizar oportunisticamente o espectro após a deteção e verificação de que o PU está inativo. Neste último caso, o SU deverá parar de transmitir quando o PU ficar ativo. Nesta tese é abordada a tarefa de deteção espectral, que é essencial para proporcionar a partilha dinâmica do espectro entre PUs e SUs. Mostra-se que a Função de Correlação Espectral (Spectral Correlation Function - SCF) e a Função de Coerência Espectral (Spectral Coherence Function - SCoF) permitem o desenvolvimento de um algoritmo robusto de deteção de sinal, explorando as características ciclo-estacionárias dos sinais de comunicação de dados. Propõe-se uma melhoria ao algoritmo mais utilizado para cálculo da SCF – o método FAM (FFT Accumulation Method) - para permitir o cálculo mais eficiente da SCF numa região local/ampliada do plano de suporte / (plano de frequência/frequência de ciclo). Esta melhoria permite a identificação rápida de bandas espectrais em uso por PUs ou livres, num cenário de amostragem de banda larga. Adicionalmente, é feita a caracterização da densidade de probabilidade das estimativas da SCF e SCoF quando apenas o ruído está presente, o que permite a definição de um limiar adaptativo, para desenvolver um detetor de Taxa de Falso Alarme Constante (Constant False Alarm Rate – CFAR) sem conhecimento do ruído de fundo (usando a SCoF) e também um detetor CFAR e Taxa de Deteção Constante (Constant Detection Rate – CDR), quando se utiliza aquela caracterização para obter uma estimativa da variância do ruído de fundo (usando a SCF)

Análisis de soluciones tecnológicas que utilicen el uso compartido de espectro y propuestas técnicas para su implementación en el marco normativo peruano

El espectro radioeléctrico es el insumo esencial para prestar servicios inalámbricos. Un correcto y eficiente uso del mismo permite que los prestadores de estos servicios, en particular, los servicios móviles, puedan atender de manera eficaz y con calidad de servicio a sus usuarios en un escenario en donde se observa una creciente demanda exponencial de datos y de dispositivos conectados a la Internet. No obstante, el espectro radioeléctrico para servicios inalámbricos es un recurso escaso, por lo que establecer el máximo provecho de uso, utilizando soluciones tecnológicas que permitan compartir el uso del mismo entre diversos servicios inalámbricos, con el menor grado de interferencia entre ellos es de suma utilidad para maximizar el uso eficiente del espectro. Es así que la presente tesis, tiene como objetivo explorar diversas soluciones tecnológicas y regulatorias como: i) el Roaming Nacional, ii) la compartición de infraestructura activa con espectro compartido, iii) la asignación dinámica de espectro, iv) los operadores móviles virtuales y v) los operadores de infraestructura móvil rural, que permitan compartir de manera efectiva el uso del espectro radioeléctrico y mejorar el uso eficiente del mismo. Para ello, se realiza una revisión del estado del arte de dichas soluciones tecnológicas y regulatorias, se revisa la experiencia internacional de la implementación de las mismas en Latinoamérica Europa y Asia, así como un análisis técnico y regulatorio de las ventajas y desventajas de las mismas. Luego de ello, se proponen criterios técnicos que se deben de considerar en caso se implementen dichas soluciones tecnológicas en el mercado peruano, ya sea de manera obligatoria para todo el sector o criterios técnicos generales para aprobar acuerdos privados entre operadores móviles. Asimismo, se mencionan cuáles serían los cambios normativos necesarios para la implementación de las mismas a nivel regulatorio. Finalmente, como parte de las recomendaciones de la presente tesis se propone una línea de tiempo de adopción de dichas alternativas tecnológicas revisadas, así como propuestas para realizar proyectos pilotos que contemple el uso de los Espacios en Blanco de Espectro por el Fondo de Inversión en Telecomunicaciones. Asimismo, se recomienda que para futuros estudios, se estima necesario que se estudie una nueva metodología de que permita al concedente del espectro radioeléctrico en el Perú (Ministerio de Transporte y Comunicaciones) evaluar de mejor manera las metas de uso del espectro radioeléctrico en las concesiones de espectro, toda vez que la actualmente vigente no permite maximizar el uso eficiente del espectro radioeléctrico. Asimismo, se recomienda incentivar el uso del espectro no licenciado en conjunto con espectro licenciado por parte de los operadores móviles, con la finalidad de brindar mayores facilidades para atender la exponencial demanda de datos del sector, mediante la revisión de regulaciones que permitan un uso justo del espectro en bandas como la de 5.8 GHz.Tesi

Internet of Things From Hype to Reality

The Internet of Things (IoT) has gained significant mindshare, let alone attention, in academia and the industry especially over the past few years. The reasons behind this interest are the potential capabilities that IoT promises to offer. On the personal level, it paints a picture of a future world where all the things in our ambient environment are connected to the Internet and seamlessly communicate with each other to operate intelligently. The ultimate goal is to enable objects around us to efficiently sense our surroundings, inexpensively communicate, and ultimately create a better environment for us: one where everyday objects act based on what we need and like without explicit instructions

Towards realisation of spectrum sharing of cognitive radio networks

Cognitive radio networks (CRN) have emerged as a promising solution to spectrum shortcoming, thanks to Professor Mitola who coined Cognitive Radios. To enable efficient communications, CRNs need to avoid interference to both Primary (licensee) Users (PUs), and among themselves (called self-coexistence). In this thesis, we focus on self-coexistence issues. Very briefly, the problems are categorised into intentional and unintentional interference. Firstly, unintentional interference includes: 1) CRNs administration; 2) Overcrowded CRNs Situation; 3) Missed spectrum detection; 4) Inter-cell Interference (ICI); and 5) Inability to model Secondary Users’ (SUs) activity. In intentional interference there is Primary User Emulation Attack (PUEA). To administer CRN operations (Prob. 1), in our first contribution, we proposed CogMnet, which aims to manage the spectrum sharing of centralised networks. CogMnet divides the country into locations. It then dedicates a real-time database for each location to record CRNs’ utilisations in real time, where each database includes three storage units: Networks locations storage unit; Real-time storage unit; and Historical storage unit. To tackle Prob. 2, our second contribution is CRNAC, a network admission control algorithm that aims to calculate the maximum number of CRNs allowed in any location. CRNAC has been tested and evaluated using MATLAB. To prevent research problems 3, 4, and to tackle research problem (5), our third contribution is RCNC, a new design for an infrastructure-based CRN core. The architecture of RCNC consists of two engines: Monitor and Coordinator Engine (MNCE) and Modified Cognitive Engine (MCE). Comprehensive simulation scenarios using ICS Designer (by ATDI) have validated some of RCNC’s components. In the last contribution, to deter PUEA (the intentional interference type), we developed a PUEA Deterrent (PUED) algorithm capable of detecting PUEAs commission details. PUED must be implemented by a PUEA Identifier Component in the MNCE in RCNC after every spectrum handing off. Therefore, PUED works like a CCTV system. According to criminology, robust CCTV systems have shown a significant prevention of clear visible theft, reducing crime rates by 80%. Therefore, we believe that our algorithm will do the same. Extensive simulations using a Vienna simulator showed the effectiveness of the PUED algorithm in terms of improving CRNs’ performance