Pub Date : 2011-05-03DOI: 10.1109/DYSPAN.2011.5936252
R. Jantti, Jussi Kerttula, K. Koufos, K. Ruttik
In US FCC and in Europe ECC have outlined the rules for TV-band secondary use. In this paper we apply those rules and compute how much white space is available in Finland. The results are expressed in terms of available secondary channels and secondary system capacity. As a secondary system we use cellular networks with different cell sizes. Unfortunately, the current secondary spectrum usage rules do not protect the TV receivers sufficiently well. Even if each individual secondary transmitter obey them, together their aggregate interference can still disrupt the TV reception. We compute how much aggregate interference a secondary network generates if the network is designed either by FCC or ECC rules. We discover that only for a low secondary transmitters' density, the TV reception will not be disturbed. We can conclude that current white space usage rules are not adequate for protecting the TV receivers. There is a need to develop constraints that consider not only secondary transmission powers but also transmitters' density.
{"title":"Aggregate interference with FCC and ECC white space usage rules: Case study in Finland","authors":"R. Jantti, Jussi Kerttula, K. Koufos, K. Ruttik","doi":"10.1109/DYSPAN.2011.5936252","DOIUrl":"https://doi.org/10.1109/DYSPAN.2011.5936252","url":null,"abstract":"In US FCC and in Europe ECC have outlined the rules for TV-band secondary use. In this paper we apply those rules and compute how much white space is available in Finland. The results are expressed in terms of available secondary channels and secondary system capacity. As a secondary system we use cellular networks with different cell sizes. Unfortunately, the current secondary spectrum usage rules do not protect the TV receivers sufficiently well. Even if each individual secondary transmitter obey them, together their aggregate interference can still disrupt the TV reception. We compute how much aggregate interference a secondary network generates if the network is designed either by FCC or ECC rules. We discover that only for a low secondary transmitters' density, the TV reception will not be disturbed. We can conclude that current white space usage rules are not adequate for protecting the TV receivers. There is a need to develop constraints that consider not only secondary transmission powers but also transmitters' density.","PeriodicalId":119856,"journal":{"name":"2011 IEEE International Symposium on Dynamic Spectrum Access Networks (DySPAN)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133810155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-03DOI: 10.1109/DYSPAN.2011.5936244
Yonghong Zeng, Ying-Chang Liang, M. Chia
Since a cognitive radio does not have fixed spectra, it may need to sense a very large frequency range to find an available band. The sensed aggregate bandwidth could be as large as several GHz. This is especially challenging if the center frequencies and bandwidths of the sensed signals are unknown and need to be detected. In this paper, an edge based wideband sensing is proposed. The method first uses the product of wavelet transforms at different scales to detect the edges (sharp changing points) of the power spectral density (PSD) of the received signal. It then forms the possible bands based on the detected edges. Thereafter, it applies a multi-band detection scheme to classify the bands as occupied or vacant. Finally, the signal to noise ratio (SNR) of each occupied band is estimated. Performance evaluation is also a complicated issue for wideband sensing. Other than the conventional metrics as probability of detection and probability of false alarm, three new criteria are proposed to evaluate the performance of a wideband sensing. Simulations are provided to verify the methods.
{"title":"Edge based wideband sensing for cognitive radio: Algorithm and performance evaluation","authors":"Yonghong Zeng, Ying-Chang Liang, M. Chia","doi":"10.1109/DYSPAN.2011.5936244","DOIUrl":"https://doi.org/10.1109/DYSPAN.2011.5936244","url":null,"abstract":"Since a cognitive radio does not have fixed spectra, it may need to sense a very large frequency range to find an available band. The sensed aggregate bandwidth could be as large as several GHz. This is especially challenging if the center frequencies and bandwidths of the sensed signals are unknown and need to be detected. In this paper, an edge based wideband sensing is proposed. The method first uses the product of wavelet transforms at different scales to detect the edges (sharp changing points) of the power spectral density (PSD) of the received signal. It then forms the possible bands based on the detected edges. Thereafter, it applies a multi-band detection scheme to classify the bands as occupied or vacant. Finally, the signal to noise ratio (SNR) of each occupied band is estimated. Performance evaluation is also a complicated issue for wideband sensing. Other than the conventional metrics as probability of detection and probability of false alarm, three new criteria are proposed to evaluate the performance of a wideband sensing. Simulations are provided to verify the methods.","PeriodicalId":119856,"journal":{"name":"2011 IEEE International Symposium on Dynamic Spectrum Access Networks (DySPAN)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115745334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-03DOI: 10.1109/DYSPAN.2011.5936223
T. Forde, I. Macaluso, L. Doyle
The focus of this paper is to progress a discussion about the redefinition of what it means to be a cellular network operator. Alternative modes of ownership may allow for the creation of more flexible cellular networking environments in which competition for packages of resources, i.e. the licenced spectrum, the RAN and core network, ensures that the most efficient architectures win out. This paper introduces the concept of the Cellular Network Cloud and Utility Cellular Networking as a means to explore the possibilities for such revolution in the way in which cellular networks are owned and operated. As a step towards evaluating the technical feasibility of such a paradigm, a flexible auction model that enables us to auction spectrum as a continuous good, as opposed to a collection of discrete items, is presented.
{"title":"Exclusive sharing & virtualization of the cellular network","authors":"T. Forde, I. Macaluso, L. Doyle","doi":"10.1109/DYSPAN.2011.5936223","DOIUrl":"https://doi.org/10.1109/DYSPAN.2011.5936223","url":null,"abstract":"The focus of this paper is to progress a discussion about the redefinition of what it means to be a cellular network operator. Alternative modes of ownership may allow for the creation of more flexible cellular networking environments in which competition for packages of resources, i.e. the licenced spectrum, the RAN and core network, ensures that the most efficient architectures win out. This paper introduces the concept of the Cellular Network Cloud and Utility Cellular Networking as a means to explore the possibilities for such revolution in the way in which cellular networks are owned and operated. As a step towards evaluating the technical feasibility of such a paradigm, a flexible auction model that enables us to auction spectrum as a continuous good, as opposed to a collection of discrete items, is presented.","PeriodicalId":119856,"journal":{"name":"2011 IEEE International Symposium on Dynamic Spectrum Access Networks (DySPAN)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129669672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-03DOI: 10.1109/DYSPAN.2011.5936272
T. Harrold, R. Cepeda, M. Beach
This paper describes the results from a series of long-term observations of spectrum occupancy in the range 300 MHz–4.9 GHz made at a single location. Over 6 months of data has been gathered from a measurement system that is designed to operate continuously, allowing a full picture of spectrum occupancy to be built up. The large amount of data captured permits analysis to identify the portions of spectrum that are occupied non-continuously (i.e. with a duty cycle of less than 100%); these channels might be most suitable for use by a cognitive radio (CR) system that is able to identify temporary spectrum holes and then exploit them. The aim of performing a comprehensive analysis of channel occupancy and its variability is to improve the potential for smart spectrum access by CR devices, by informing their choices concerning the particular portions of spectrum to scan, and how frequently. Results allow measurement channels to be categorised according to their duty cycle; spectrum with a duty cycle between 10% and 90% is considered to be particularly suitable and is found in the regions below 500 MHz and between 1 GHz and 1.2 GHz. A predictable pattern of time occupancy is discovered, caused by variable activity in the portions of spectrum allocated to cellular systems. The characteristics of the occupancy duty cycle according to the time of day is also investigated; some frequencies are shown to exhibit considerable variation of occupancy depending on the hour of observation. A subset of channels is selected for more detailed investigation including short-term variations in channel occupancy.
{"title":"Long-term measurements of spectrum occupancy characteristics","authors":"T. Harrold, R. Cepeda, M. Beach","doi":"10.1109/DYSPAN.2011.5936272","DOIUrl":"https://doi.org/10.1109/DYSPAN.2011.5936272","url":null,"abstract":"This paper describes the results from a series of long-term observations of spectrum occupancy in the range 300 MHz–4.9 GHz made at a single location. Over 6 months of data has been gathered from a measurement system that is designed to operate continuously, allowing a full picture of spectrum occupancy to be built up. The large amount of data captured permits analysis to identify the portions of spectrum that are occupied non-continuously (i.e. with a duty cycle of less than 100%); these channels might be most suitable for use by a cognitive radio (CR) system that is able to identify temporary spectrum holes and then exploit them. The aim of performing a comprehensive analysis of channel occupancy and its variability is to improve the potential for smart spectrum access by CR devices, by informing their choices concerning the particular portions of spectrum to scan, and how frequently. Results allow measurement channels to be categorised according to their duty cycle; spectrum with a duty cycle between 10% and 90% is considered to be particularly suitable and is found in the regions below 500 MHz and between 1 GHz and 1.2 GHz. A predictable pattern of time occupancy is discovered, caused by variable activity in the portions of spectrum allocated to cellular systems. The characteristics of the occupancy duty cycle according to the time of day is also investigated; some frequencies are shown to exhibit considerable variation of occupancy depending on the hour of observation. A subset of channels is selected for more detailed investigation including short-term variations in channel occupancy.","PeriodicalId":119856,"journal":{"name":"2011 IEEE International Symposium on Dynamic Spectrum Access Networks (DySPAN)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130818651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-03DOI: 10.1109/DYSPAN.2011.5936209
M. Weiss
DSA research must explicitly consider the perspective of secondary users. This paper considers the spatio-temporal properties of spectrum holes as they impact the secondary user's communications needs. Like Weiss et. al. [1], this paper develops a taxonomy of spectrum holes from the point of view of the secondary user. Each type of spectrum hole is analyzed for the kinds of communications requirements that can be supported, illustrated, where possible, by existing measurement data. The analysis concludes that a secondary user's ability to meet their communications need varies considerably. More detailed analysis of the spatio-temporal density of spectrum holes would be necessary to further quantify these conclusions.
{"title":"Spatio-temporal spectrum holes and the secondary user","authors":"M. Weiss","doi":"10.1109/DYSPAN.2011.5936209","DOIUrl":"https://doi.org/10.1109/DYSPAN.2011.5936209","url":null,"abstract":"DSA research must explicitly consider the perspective of secondary users. This paper considers the spatio-temporal properties of spectrum holes as they impact the secondary user's communications needs. Like Weiss et. al. [1], this paper develops a taxonomy of spectrum holes from the point of view of the secondary user. Each type of spectrum hole is analyzed for the kinds of communications requirements that can be supported, illustrated, where possible, by existing measurement data. The analysis concludes that a secondary user's ability to meet their communications need varies considerably. More detailed analysis of the spatio-temporal density of spectrum holes would be necessary to further quantify these conclusions.","PeriodicalId":119856,"journal":{"name":"2011 IEEE International Symposium on Dynamic Spectrum Access Networks (DySPAN)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114885688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-03DOI: 10.1109/DYSPAN.2011.5936195
Tanim M. Taher, R. Bacchus, K. Zdunek, D. Roberson
This paper summarizes some of the results of measurements and related analysis efforts at the Illinois Institute of Technology (IIT) Spectrum Observatory in Chicago over the past three years. The results are unique in the sense that the spectral occupancy estimates are based on multiple years of observations, whereas previous studies produced occupancy numbers based on short term snapshot measurements, often of a few hours duration or at most spanning a few days or weeks. The measurements are also presented in a novel way: the occupancy data in a band of interest during a one year span is graphed as a 2-dimensional image that visually reveals daily, weekly, and yearly trends and anomalies. The main objective of this paper is to present year by year first-order statistics about the spectral occupancy across multiple bands, but more details are presented about radio usage in a few bands like the TV band. In particular, we examine the spectral opportunities that are seen in the newly available “TV White Space”. The results illustrate occupancy trends and notable spectral events, such as the 2009 broadcast television transition and the related vacating of the 700 MHz band, which have created significant spectrum opportunities in the 30–1000 MHz region. The trends reported are applicable to long term spectrum modeling, spectrum planning, and regulatory decision-making efforts applicable to dynamic spectrum access networks.
{"title":"Long-term spectral occupancy findings in Chicago","authors":"Tanim M. Taher, R. Bacchus, K. Zdunek, D. Roberson","doi":"10.1109/DYSPAN.2011.5936195","DOIUrl":"https://doi.org/10.1109/DYSPAN.2011.5936195","url":null,"abstract":"This paper summarizes some of the results of measurements and related analysis efforts at the Illinois Institute of Technology (IIT) Spectrum Observatory in Chicago over the past three years. The results are unique in the sense that the spectral occupancy estimates are based on multiple years of observations, whereas previous studies produced occupancy numbers based on short term snapshot measurements, often of a few hours duration or at most spanning a few days or weeks. The measurements are also presented in a novel way: the occupancy data in a band of interest during a one year span is graphed as a 2-dimensional image that visually reveals daily, weekly, and yearly trends and anomalies. The main objective of this paper is to present year by year first-order statistics about the spectral occupancy across multiple bands, but more details are presented about radio usage in a few bands like the TV band. In particular, we examine the spectral opportunities that are seen in the newly available “TV White Space”. The results illustrate occupancy trends and notable spectral events, such as the 2009 broadcast television transition and the related vacating of the 700 MHz band, which have created significant spectrum opportunities in the 30–1000 MHz region. The trends reported are applicable to long term spectrum modeling, spectrum planning, and regulatory decision-making efforts applicable to dynamic spectrum access networks.","PeriodicalId":119856,"journal":{"name":"2011 IEEE International Symposium on Dynamic Spectrum Access Networks (DySPAN)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116413258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-03DOI: 10.1109/DYSPAN.2011.5936228
Marcin Parzy, H. Bogucka
The paper considers a new spectrum sharing approach in TV white spaces (TVWS) areas using an auction of non-identical objects taking the bandwidth and power requirements of the secondary users into account. The commodity of the auction is the available frequency band with propagation-signal power limitations. These frequency resources available in TVWS may be distributed among the telecommunication operators and service providers of various types (called players) operating in a given area. The available spectrum-band may be divided into blocks having the same or different sizes and different maximum allowable power. The resource allocation problem in frequency and power domain has been defined as an optimization problem where maximum payoff of the central trading entity (called spectrum broker) is the optimization goal. The problem of the best matching of the players demands, their bids and the auction solution to the available spectrum-holes have been discussed and highlighted. In the auction solution the branch and cut technique, known from integer programming, was applied so the complexity of the optimization algorithm was reduced significantly. Simulations results are also provided.
{"title":"Non-identical objects auction for spectrum sharing in TV white spaces — The perspective of service providers as secondary users","authors":"Marcin Parzy, H. Bogucka","doi":"10.1109/DYSPAN.2011.5936228","DOIUrl":"https://doi.org/10.1109/DYSPAN.2011.5936228","url":null,"abstract":"The paper considers a new spectrum sharing approach in TV white spaces (TVWS) areas using an auction of non-identical objects taking the bandwidth and power requirements of the secondary users into account. The commodity of the auction is the available frequency band with propagation-signal power limitations. These frequency resources available in TVWS may be distributed among the telecommunication operators and service providers of various types (called players) operating in a given area. The available spectrum-band may be divided into blocks having the same or different sizes and different maximum allowable power. The resource allocation problem in frequency and power domain has been defined as an optimization problem where maximum payoff of the central trading entity (called spectrum broker) is the optimization goal. The problem of the best matching of the players demands, their bids and the auction solution to the available spectrum-holes have been discussed and highlighted. In the auction solution the branch and cut technique, known from integer programming, was applied so the complexity of the optimization algorithm was reduced significantly. Simulations results are also provided.","PeriodicalId":119856,"journal":{"name":"2011 IEEE International Symposium on Dynamic Spectrum Access Networks (DySPAN)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129933374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-03DOI: 10.1109/DYSPAN.2011.5936212
V. Gonçalves, S. Pollin
The main challenge to allow for use of the so-called TV White Spaces is to achieve a reliable approach for detecting presence of licensed users ensuring that harmful interference to television signals and other incumbent services does not occur. In the current debate, there is a trend towards the use of a geo-location database only, driven by the fear that other techniques fail to achieve the required detection reliability. Therefore, in this paper we intend to assess if the technical and business value of sensing in the context of TVWS should be neglected. Taking in consideration the discussion on the adequate technical requirements currently taking place in Europe and the USA, the cost and performance of the proposed techniques for local sensing, distributed sensing and geo-location database are compared through a simple model. As a result, we conclude that using a distributed sensing solution based on low-cost low-power sensing engines, we could achieve a solution with hardware and energy costs a par with the geo-location database. However, by assessing the costs and business impacts for stakeholders such as manufacturers and White Spaces Service Providers we conclude that in the geo-location database solution, regulators, White Spaces Service Providers, White Spaces Database Providers and consumers may incur additional infrastructure, maintenance and administrative costs compared to a distributed sensing solution. Consequently, we are of the opinion that the distributed sensing solution in the context of TVWS does indeed present value and its business and technical impact should be considered in further research and regulatory activities.
{"title":"The value of sensing for TV White Spaces","authors":"V. Gonçalves, S. Pollin","doi":"10.1109/DYSPAN.2011.5936212","DOIUrl":"https://doi.org/10.1109/DYSPAN.2011.5936212","url":null,"abstract":"The main challenge to allow for use of the so-called TV White Spaces is to achieve a reliable approach for detecting presence of licensed users ensuring that harmful interference to television signals and other incumbent services does not occur. In the current debate, there is a trend towards the use of a geo-location database only, driven by the fear that other techniques fail to achieve the required detection reliability. Therefore, in this paper we intend to assess if the technical and business value of sensing in the context of TVWS should be neglected. Taking in consideration the discussion on the adequate technical requirements currently taking place in Europe and the USA, the cost and performance of the proposed techniques for local sensing, distributed sensing and geo-location database are compared through a simple model. As a result, we conclude that using a distributed sensing solution based on low-cost low-power sensing engines, we could achieve a solution with hardware and energy costs a par with the geo-location database. However, by assessing the costs and business impacts for stakeholders such as manufacturers and White Spaces Service Providers we conclude that in the geo-location database solution, regulators, White Spaces Service Providers, White Spaces Database Providers and consumers may incur additional infrastructure, maintenance and administrative costs compared to a distributed sensing solution. Consequently, we are of the opinion that the distributed sensing solution in the context of TVWS does indeed present value and its business and technical impact should be considered in further research and regulatory activities.","PeriodicalId":119856,"journal":{"name":"2011 IEEE International Symposium on Dynamic Spectrum Access Networks (DySPAN)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130764104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-03DOI: 10.1109/DYSPAN.2011.5936246
D. Saha, A. Dutta, D. Grunwald, D. Sicker
Recent efforts in making licensed spectrum available for secondary use have opened up new opportunities and has redefined the meaning of sharing spectrum. Sharing spectrum requires aggregation of multiple non-contiguous bands of varying width to communicate as a network. Rather than limiting spectrum access to fixed width narrowband channels, they should be treated as conventions that are highly flexible and allow for simultaneous multi-user communication among a variety of heterogeneous devices with different transceiver capabilities. Non-Contiguous Orthogonal Frequency Division Multiplexing (NC-OFDM) is a physical layer technique that can be utilized to achieve this goal. Unlike the contiguous channelized access model, wideband non-contiguous access posses a critical challenge of synchronization. In this paper, we propose a practical algorithm and hardware implementation to overcome this challenge. Equipped with this blind synchronizer, we propose a Medium Access Control (MAC) layer design to enable flexible channel access while achieving co-existence with the incumbent and other secondary heterogeneous networks. The blind synchronization technique vastly simplifies channel rendezvous in the secondary network and provides faster migration to a vacant spectrum. Through extensive simulations under varying signal-to-noise ratio (SNR) and spectral occupancy, we show significant improvement over existing algorithms employed for NC-OFDM synchronization in cognitive radios and make wideband cognitive radio networks a distinct possibility in the near future.
{"title":"Blind synchronization for NC-OFDM — When “channels” are conventions, not mandates","authors":"D. Saha, A. Dutta, D. Grunwald, D. Sicker","doi":"10.1109/DYSPAN.2011.5936246","DOIUrl":"https://doi.org/10.1109/DYSPAN.2011.5936246","url":null,"abstract":"Recent efforts in making licensed spectrum available for secondary use have opened up new opportunities and has redefined the meaning of sharing spectrum. Sharing spectrum requires aggregation of multiple non-contiguous bands of varying width to communicate as a network. Rather than limiting spectrum access to fixed width narrowband channels, they should be treated as conventions that are highly flexible and allow for simultaneous multi-user communication among a variety of heterogeneous devices with different transceiver capabilities. Non-Contiguous Orthogonal Frequency Division Multiplexing (NC-OFDM) is a physical layer technique that can be utilized to achieve this goal. Unlike the contiguous channelized access model, wideband non-contiguous access posses a critical challenge of synchronization. In this paper, we propose a practical algorithm and hardware implementation to overcome this challenge. Equipped with this blind synchronizer, we propose a Medium Access Control (MAC) layer design to enable flexible channel access while achieving co-existence with the incumbent and other secondary heterogeneous networks. The blind synchronization technique vastly simplifies channel rendezvous in the secondary network and provides faster migration to a vacant spectrum. Through extensive simulations under varying signal-to-noise ratio (SNR) and spectral occupancy, we show significant improvement over existing algorithms employed for NC-OFDM synchronization in cognitive radios and make wideband cognitive radio networks a distinct possibility in the near future.","PeriodicalId":119856,"journal":{"name":"2011 IEEE International Symposium on Dynamic Spectrum Access Networks (DySPAN)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123579568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-03DOI: 10.1109/DYSPAN.2011.5936218
Raamkumar Balamurthi, Harshita Joshi, C. Nguyen, A. Sadek, S. Shellhammer, Cong Shen
The paper provides an overview of a real-time spectrum sensing prototype operating in the TV white space. There has been considerable research on the feasibility of spectrum sensing in the TV white space. This is a challenge due to the very weak signal power levels specified by the FCC. In the TV white space there are a number of incumbent systems that must be protected from interference by a TV white space device. One method of protection is spectrum sensing, which can be used in locations where geo-location is problematic. This paper describes a real-time prototype which performs sensing for ATSC, NTSC and wireless microphones in the UHF TV band. An overview of the sensing techniques are provides as well as a description of how the sensing techniques are realized in the prototype.
{"title":"A TV white space spectrum sensing prototype","authors":"Raamkumar Balamurthi, Harshita Joshi, C. Nguyen, A. Sadek, S. Shellhammer, Cong Shen","doi":"10.1109/DYSPAN.2011.5936218","DOIUrl":"https://doi.org/10.1109/DYSPAN.2011.5936218","url":null,"abstract":"The paper provides an overview of a real-time spectrum sensing prototype operating in the TV white space. There has been considerable research on the feasibility of spectrum sensing in the TV white space. This is a challenge due to the very weak signal power levels specified by the FCC. In the TV white space there are a number of incumbent systems that must be protected from interference by a TV white space device. One method of protection is spectrum sensing, which can be used in locations where geo-location is problematic. This paper describes a real-time prototype which performs sensing for ATSC, NTSC and wireless microphones in the UHF TV band. An overview of the sensing techniques are provides as well as a description of how the sensing techniques are realized in the prototype.","PeriodicalId":119856,"journal":{"name":"2011 IEEE International Symposium on Dynamic Spectrum Access Networks (DySPAN)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123029890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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