Application of radio environment maps for dynamic broadband access in TV bands in urban areas

Spectrum sharing based on the dedicated databases, particularly in the context of TV band, is widely considered as a promising tool for better spectrum utilization in the future wireless networks. Practical realization of this paradigm entails the need for the true protection of the incumbent system, and at the same time the guarantee of the quality of the services offered to the secondary users. In this respect, this papers discusses the results achieved in numerous measurement campaigns performed for last years in two European cities, i.e., Poznan, Poland and Barcelona, Spain. Both indoor and outdoor measurements of the TV band have been compared with the main purpose of true identification of key practical considerations for spectrum sharing in the TV white spaces. As such the paper constitutes a concise summary of various analyzes and provides pragmatic guidelines for deployment of radio-environment maps (REM) based systems. Based on the conducted measurements and achieved results, the set of practical conclusions for REMs has been deduced, and the prospective procedure of deployment of such a network has been proposed.Peer ReviewedPostprint (published version

Deployment of Indoor LTE Small-Cells in TV White Spaces

In this thesis, we present a systematic computer-based approach to solve the problem of optimum transmitter placement for indoor LTE coverage systems operating in the TVWS. This approach is supported with rigorous simulations that reflect very promising results.This work focuses on the deployment of indoor LTE small cells acting as secondary transmitters in TVWS. Proposed methods make use of measurements stored in a Radio Environment Map (REM) that characterizes the DVB-T reception inside the building under consideration. Under this framework, this work analyses two different approaches for the deployment of small cells. First approach is based on maximizing total secondary transmit power inside the building, while the second approach is based on maximizing the percentage of positions having a Signal to Interference and Noise Ratio (SINR) above a desired threshold. Approaches are validated by means of rigorous simulations supported by real measurements of DVB-T signal reception. Results include optimum secondary transmitter placement, and transmit power values for providing indoor LTE coverage considering operating in a channel adjacent to the one used by DVB-T. These results are compared against exhaustive enumeration techniques and proven to provide very accurate results. Results reveal that when considering system capacity or network throughput, the second approach is more efficient and provides better results than the first approach. To the author's best knowledge, this model is the only model that provides an actual deployment strategy of indoor LTE secondary transmitters while considering interference constraints from adjacent channel DVB-T transmission. While our approaches are only tested in the considered building, the methods used are generic and can be applied in the same manner within any indoor environment provided that the REM for that environment is established

Spectrum cartography techniques, challenges, opportunities, and applications: A survey

The spectrum cartography finds applications in several areas such as cognitive radios, spectrum aware communications, machine-type communications, Internet of Things, connected vehicles, wireless sensor networks, and radio frequency management systems, etc. This paper presents a survey on state-of-the-art of spectrum cartography techniques for the construction of various radio environment maps (REMs). Following a brief overview on spectrum cartography, various techniques considered to construct the REMs such as channel gain map, power spectral density map, power map, spectrum map, power propagation map, radio frequency map, and interference map are reviewed. In this paper, we compare the performance of the different spectrum cartography methods in terms of mean absolute error, mean square error, normalized mean square error, and root mean square error. The information presented in this paper aims to serve as a practical reference guide for various spectrum cartography methods for constructing different REMs. Finally, some of the open issues and challenges for future research and development are discussed.publishedVersio

A cognitive QoS management framework for WLANs

Due to the precipitous growth of wireless networks and the paucity of spectrum, more interference is imposed to the wireless terminals which constraints their performance. In order to preserve such performance degradation, this paper proposes a framework which uses cognitive radio techniques for quality of service (QoS) management of wireless local area networks (LANs). The framework incorporates radio environment maps as input to a cognitive decision engine that steers the network to optimize its QoS parameters such as throughput. A novel experimentally verified heuristic physical model is developed to predict and optimize the throughput of wireless terminals. The framework was applied to realistic stationary and time-variant interference scenarios where an average throughput gain of 344% was achieved in the stationary interference scenario and 70% to 183% was gained in the time-variant interference scenario

D6.2 - Prototype description and field trial results

Deliverable D6.2 del projecte FARAMIRPostprint (published version

D21.3 Analysis of initial results at EuWIN@CTTC

Deliverable D21.3 del projecte europeu NEWCOM#The nature of this Deliverable of WP2.1 (“Radio interfaces for next-generation wireless systems”) is mainly descriptive and its purpose is to provide a report on the status of the different Joint Research Activities (JRAs) currently ongoing, some of them being performed on the facilities that are available at EuWInPeer ReviewedPreprin

Deployment of Indoor LTE Small-Cells in TV White Spaces

In this thesis, we present a systematic computer-based approach to solve the problem of optimum transmitter placement for indoor LTE coverage systems operating in the TVWS. This approach is supported with rigorous simulations that reflect very promising results.This work focuses on the deployment of indoor LTE small cells acting as secondary transmitters in TVWS. Proposed methods make use of measurements stored in a Radio Environment Map (REM) that characterizes the DVB-T reception inside the building under consideration. Under this framework, this work analyses two different approaches for the deployment of small cells. First approach is based on maximizing total secondary transmit power inside the building, while the second approach is based on maximizing the percentage of positions having a Signal to Interference and Noise Ratio (SINR) above a desired threshold. Approaches are validated by means of rigorous simulations supported by real measurements of DVB-T signal reception. Results include optimum secondary transmitter placement, and transmit power values for providing indoor LTE coverage considering operating in a channel adjacent to the one used by DVB-T. These results are compared against exhaustive enumeration techniques and proven to provide very accurate results. Results reveal that when considering system capacity or network throughput, the second approach is more efficient and provides better results than the first approach. To the author's best knowledge, this model is the only model that provides an actual deployment strategy of indoor LTE secondary transmitters while considering interference constraints from adjacent channel DVB-T transmission. While our approaches are only tested in the considered building, the methods used are generic and can be applied in the same manner within any indoor environment provided that the REM for that environment is established

Field Measurements in Determining Incumbent Spectrum Utilization and Protection Criteria in Wireless Co-existence Studies

Studies of spectrum sharing and co-existence between different wireless communication systems are important, as the current aim is to optimize their spectrum utilization and shift from static exclusive spectrum allocation to more dynamic co-existence of different systems within same frequency bands. The main goal of this thesis is to provide measurement methodologies for obtaining realistic results in modeling incumbent spectrum utilization and in determining incumbent protection criteria. The following research questions are considered in this thesis: Q1) How should field measurements be conducted and used to model incumbent spectrum utilization? Q2) How should field measurements be conducted and used to determine protection criteria for incumbents in a co-existence scenario with mobile broadband? and Q3) Which licensing methods and technological solutions are feasible to enable spectrum sharing in frequency bands with incumbents? To answer to Q1, this thesis describes the development of a spectrum observatory network concept created through international collaboration and presents measurement methodologies, which allow to obtain realistic spectrum occupancy data over geographical areas using interference map concept. A cautious approach should be taken in making strong conclusions from previous single fixed location spectrum occupancy studies, and measurements covering larger geographical areas might be needed if the measurement results are to be used in making spectrum management decisions. The field interference measurements considered in Q2 are not covered well in the current research literature. The measurements are expensive to conduct as they require substantial human resources, test network infrastructure, professional level measurement devices and radio licenses. However, field measurements are needed to study and verify hypotheses from computer simulations or theoretical analyses in realistic operating conditions, as field measurement conditions can not or are not practical to be adequately modeled in simulations. This thesis proposes measurement methodologies to obtain realistic results from field interference measurements, taking into account the propagation environments and external sources of interference. Less expensive simulations and laboratory measurements should be used both to aid in the planning of field measurements and to complement the results obtained from field measurements. Q3 is investigated through several field interference measurement campaigns to determine incumbent protection criteria and by analyzing the spectrum observatory data to determine the occupancy and trends in incumbent spectrum utilization. The field interference measurement campaigns have been conducted in real TV White Space, LTE Supplemental Downlink and Licensed Shared Access test network environments, and the obtained measurement results have been contributed to the development of the European spectrum regulation. In addition, field measurements have been conducted to contribute to the development and technical validation of the spectrum sharing frameworks. This thesis also presents an overview of the current status and possible directions in spectrum sharing. In conclusion, no single spectrum sharing method can provide universally optimal efficiency in spectrum utilization. Thus, an appropriate spectrum sharing framework should be chosen taking into account both the spectrum utilization of the current incumbents and the future needs in wireless communications.Siirretty Doriast

Rem design for cognitive radio networks in tv band

Dissenyar i crear un entorn que permeti capturar i emmagatzemar ordenadament les mesures de l'espectre radioelèctric realitzades amb l'analitzador d'espectres FSL6 de Rhode&Schwarz. L'objectiu és construir un REM (Radio Environment Map) del Campus Nord en un PC per poder-ne fer ús a posteriori, ja sigui per implementar xarxes wireless cognitives d'àrea local, xarxes oportunístiques, .....[ANGLÈS] Recent studies have demonstrated a clearly visible fact in our environment: The boom of wireless networks traffic has made raise the need of more bandwidth, due to an increment of the usage of wireless resources; every time with more and more different devices. Otherwise, other studies show an inefficient occupation of radio electric spectrum inside commercial bands; that is, not all assigned channels are currently in use by their operators. UHF TV band is an example of this situation, compounded after analogue TV switching off. Putting two previous scopes together have induced a new evolution of wireless networks: Deploying a certain kind of devices able to operate at empty channels of commercial bands. This thesis shows a way for these wireless devices to find out empty channels of a certain band and geographical location. The way has been tried out at ETSETB TelecomBCN UPC Campus Nord facilities with successful expected results.[CASTELLÀ] Estudios recientes han demostrado un hecho claramente visible en nuestro entorno: El auge de tráfico de las redes inalámbricas ha hecho aumentar la necesidad de más ancho de banda, debido a un incremento del uso de los recursos radio, cada vez con más dispositivos diferentes. Por otra parte, otros estudios muestran una ocupación del espectro radioeléctrico ineficiente dentro de las bandas comerciales; con otras palabras, no todos los canales asignados están actualmente en uso por sus operadores. La banda UHF de televisión es un ejemplo de esta situación. Juntar estos dos ámbitos anteriores ha provocado una nueva evolución de las redes inalámbricas: Desplegar un cierto tipo de dispositivos capaces de operar en los canales vacíos de las bandas comerciales. Esta tesis muestra un método para estos dispositivos radio de encontrar canales vacíos de una cierta banda y ubicación geográfica. El método ha sido probado en las instalaciones de la ETSETB TelecomBCN UPC Campus Nord con buenos resultados esperados.[CATALÀ] Estudis recents han demostrat un fet clarament visible en el nostre entorn: L’increment de tràfic de les xarxes sense fils ha fet augmentar la necessitat de més ample de banda, degut a un increment de l’ús dels recursos ràdio; cada vegada amb més dispositius diferents. D’altra banda, altres estudis mostren una ocupació de l’espectre radioelèctric ineficient dins les bandes comercials; amb altres paraules, no tots els canals assignats estan actualment en ús pels seus operadors. La banda UHF de televisió és un exemple d’aquesta situació. Ajuntar els dos àmbits anteriors ha provocat una nova evolució de les xarxes sense fils: Desplegar un cert tipus de dispositius capaços d’operar als canals buits de les bandes comercials. Aquesta tesis mostra un mètode per aquests dispositius ràdio de trobar canals buits d’una certa banda i en una ubicació geogràfica. El mètode ha estat provat a les instal·lacions de la ETSETB TelecomBCN UPC Campus Nord amb bons resultats esperats

D13.2 Techniques and performance analysis on energy- and bandwidth-efficient communications and networking

Deliverable D13.2 del projecte europeu NEWCOM#The report presents the status of the research work of the various Joint Research Activities (JRA) in WP1.3 and the results that were developed up to the second year of the project. For each activity there is a description, an illustration of the adherence to and relevance with the identified fundamental open issues, a short presentation of the main results, and a roadmap for the future joint research. In the Annex, for each JRA, the main technical details on specific scientific activities are described in detail.Peer ReviewedPostprint (published version