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During the design and development of a reliable transceiver, its performance and robustness are evaluated using channel models that simulate the propagation channel characteristics in a real-world environment. In the case of wide-area communication systems in rural areas such as those based on TV white spaces, long delay multipath fading is one of the dominant factors impairing communication quality, and it is important to apply realistic multipath fading channel models in various application scenarios. Therefore, it is necessary to develop channel measurement and modeling systems that adaptively obtain channel factors and reflect multipath propagation characteristics in various wide-area communication environments. In this study, we developed a flexible channel measurement and modeling prototype applicable to mobile IEEE 802.22-based wide-area communication systems, which can be simply implemented by using programmable hardware and software. The prototype includes a new channel modeling framework that applies an improved double exponential slope model to extract the essential factors of multipath propagation characteristics. To validate the developed prototype, a fading emulator is applied to it to measure the raw data used for modeling. As a result, the multipath fading characteristics measured with the prototype were successfully modeled and reproduced by the proposed channel modeling framework with a high fitness of root mean square delay spread distribution. The derived bit error rate characteristics agreed better with the simulation results compared to the conventional channel model.

IEEE 802.22 is a standardized WRAN (Wireless Regional Area Network) system that operates in TVWS (TV White Spaces) and aims to achieve an effective spectrum utilization. Since IEEE 802.22 offers excellent propagation characteristics in the UHF (Ultra High Frequency) band, it is expected to support a cost-effective wireless communication system in rural areas. To provide a long-distance wireless communication, it is important for the receiver design to compensate a multipath fading attributed to large differences in path lengths, while existing multipath fading channel profiles applicable to IEEE 802.22 has generalization and statistical limitations. To generally and stochastically reproduce the multipath propagation characteristics in an actual wide area environment, an algorithm to obtain a statistical channel model extracted from the field experiment data is required. In this study, we develop a novel channel modeling algorithm based on the conventional S-V (Saleh-Valenzuela) modeling algorithm that offers an approach to model and reproduce the multipath characteristics in an actual environment. The proposed channel modeling algorithm applies a dynamic GEV (Generalized Extreme Value) distribution fitting for the amplitude fluctuation of individual arrival cluster. We also evaluate the channel reproduction performance of the proposed algorithm by computer simulation using channel modeling factors calculated from the experiment result with a FE (Fading Emulator). As a result, by applying the proposed algorithm, the multipath fading characteristics measured in the experiment can be modeled, and its reproducibility is confirmed with regard to relative path power distribution, rms delay spread distribution, and BER characteristics.

TVWS (TV White Spaces) communication systems are expected as one of the promising technologies to support full-coverage and cost-effective vehicular and transportation communications because of its superior propagation characteristics. IEEE 802.22 that was standardized for point-to-multipoint fixed communications supports a wide coverage of 10–30 km. While the application of IEEE 802.22 to a vehicular network has attracted attentions, it is necessary to improve the receiver performance and to enhance its tolerance in a highly mobile multipath propagation environment. Thus, not only numerical evaluation by computer simulation with baseband signals but also experimental evaluation with RF (Radio Frequency) analog signal are vitally required. In this paper, we develop an SDR (Software Defined Radio)-based evaluation platform enabling a bench test of the PHY (Physical Layer) performance with the RF analog signal for a highly mobile IEEE 802.22 communication system. In this platform, RF signals are transmitted and received with flexibly reconfigurable hardware and software, and the received baseband signals are recorded and stored by the SDR device. The stored data are post-processed with a MATLAB-based program to evaluate transmission performance such as BER. As a measurement result, the SDR-based evaluation system achieves similar performance with computer simulation, and thus, the feasibility of the highly mobile IEEE 802.22 communication system is further demonstrated. In addition, the proposed evaluation platform is also available for the future field experiment and can encourage the development and evaluation of novel PHY algorithms.

The usage of licensed television spectrum by unlicensed user to improve spectrum utilisation has been described by the IEEE 802.22 standard which seeks to use cognitive radios for wireless regional area networks. This standard is meant for usage in the rural areas where there is low usage of the TV spectrum. To make this standard available for use in the urban areas where there is greater usage of the TV spectrum; a new spectrum utilisation technique for cognitive radios is developed. This method uses the principle of matched filtering for spectrum sensing and interference temperature management for interference control against the licensed user. In the system modelling, cognitive radio access point transmits with the maximum transmission power of 36dBm when there is absence of television signal but has to compute the appropriate transmission power which is determined by the strength of the television signal present. Simulation of the developed method was done using Java programming language. In the presence of different licensed signal levels of -34.80dBm, -14.80dBm and -7.81dBm, the developed method achieved a distance of 150m, 1.5km and 3.5km respectively at 66MHz, a capacity of 789Kb/s, and a spectral efficiency of 0.045b/s/Hz.. This developed method therefore gives improved spectrum utilisation in areas where there is higher usage of the limited spectrum.

Demand of wireless users are increasing day by day, available spectrum resources should be utilized effectively. Cognitive Radio is wireless technology which configured dynamically to adapt environmental changes and change its parameters according to vacant channels. IEEE 802.22 is a standard defined for Wireless Regional Area Networking (WRAN) to utilize TV white band channels. Under the NETSIM environment, Cognitive radio network topology is made up and analyzed its various parameters like simulation time, packets transmitted, packets errored, various codecs, and throughput.

The IEEE 802.22 standard targets rural and sparsely populated regions exploiting television white space (TVWS) technology. In these regions, there are fewer mobile users per density and end-user traffic is light. Hence, there is a need to adopt traffic aware algorithm leveraging on the end-user non-uniform traffic attributes and in essence, promote spectrum efficiency in the TVWS spectrum-management regime. This paper investigates a mechanism to encourage spectrum sharing during low end-user traffic regime motivated by financial inducement. Since incumbent coexistence has been achieved using market models, it is tractable to apply market-assisted spectrum sharing models to address self-coexistence issues in TVWS networks. The purpose of this paper is to use the market model to promote self-coexistence in TVWS networks in the uplink self-frequency reuse. Toward this goal, this paper proposes discounted spectrum price game-based resource allocation in a competitive environment (D-GRACE). Specifically, D-GRACE is a transmit power reduction strategy motivated by financial incentives during light TVWS end-user traffic. When compared with an existing non-market-inspired TVWS self-coexistence resource allocation algorithm under the same scenario, D-GRACE exhibited superior power savings of about 20% and converged after five iterations.

In this paper, a correlation-based spectrum sensing method is presented to detect the frequency holes in the licensed digital TV band when accurate existence database is not available. The data segment and field synchronization symbols of digital TV signal features are considered in this sensing method. These two approaches (features) are proposed by using the cross correlation between the time accumulated original signal pattern and a copy of this pattern with different sensing time to present the desired detection scheme at low signal to noise ratio levels. When data segment synchronization approach is considered, simulation result show that the correlator detector can detect SNR of -25dB in 19.25 msec when PFA=0.1. However for the field synchronization correlator detector, the result show that the minimum detected SNR is -30dB for sensing time of 96.4msec.

TVWS (TV White-Spaces) have been expected to support a wide coverage in heterogeneous vehicular networks due to the superior propagation properties. IEEE 802.22 is one of the standardized TVWS communication systems that supports wide-area fixed communication with a coverage of 10-30 km, and there are increasing demands on the application of IEEE 802.22 to mobile communication. In this paper, we propose a robust channel estimation scheme that takes advantage of the scattered pilot pattern of IEEE 802.22 even under the highly-mobile and long-delay multipath fading environment. The proposed scheme achieves the required BER of 2 × 10–4 for QPSK and 16QAM in the downstream at a high velocity of 80 km/h even in the presence of a higher order carrier frequency offset. Also, the required BER can be achieved for QPSK and 16QAM in the upstream in combination with the 2-branch diversity. These results demonstrate the feasibility of the wide-area mobile communication system based on IEEE 802.22 in rural areas.

Smart Grid (SG) communication architecture involves multiple network layers starting from control center to consumer areas, in a top-bottom hierarchy. At each network layer, several SG applications need to be supported with diverse Quality-of-Service (QoS) requirements. Cognitive Radio (CR) which provides efficient spectrum utilization through opportunistic spectrum access is a promising solution to meet these versatile requirements. The IEEE 802.22 Wireless Regional Area Network (WRAN) is aimed at the use of CR by allowing the unused spectrum of television broadcast service for providing broadband access to remote areas. This standard provide a variety of the modes of operation to support various QoS demands. In this paper, we provide the performance comparison of various modes of IEEE 802.22 standard when applied to different SG applications to show its compliance with the SG communication infrastructure. The frame sizes and other parameters are taken as per the SG application requirements. Furthermore, various bounds on channel quality are also provided to support the reliability requirements of different SG applications using this standard.

This work presents hardware implementation of 4 Spectrum Sensing (SS) techniques for ATSC/A53 TV signals, defined in the IEEE 802.22 standard. The implemented techniques are: Field Sync Correlation Detector (FSCD), Segment-Sync Autocorrelation Detector (SSAD), Spectral Correlation (SC), and Pilot Sensing (PS). FSCD and SSAD use the synchronization information in the ATSC signal to measure the occupancy of the channel; and SC and PS are based on the spectral features of the ATSC signal. The 4 techniques were implemented on an FPGA and their performance was checked using an ATSC signal captured in field. Both FSCD and SSAD detect ATSC signals with Signal-to-Noise Ratios (SNRs) above −14.5 dB; SC detects ATSC signals with SNRs above −25 dB; and PS detects ATSC signals with SNRS above −33 dB.

In this paper various algorithms are proposed to help IEEE 802.11af and IEEE 802.22 wireless systems to coexist in TV white space by considering multiple techniques. By using busy tone power control and multihop communication techniques improvements have been made compared to prior approaches. With this approach while IEEE 802.22 systems are protected from intra-network interference IEEE 802.11af systems are still able to continue transmitting packets. Considering the communication parameters and channel models compliant for the standards IEEE 802.11af and IEEE 802.22 system performances are investigated in terms of interfering packet rate and successful packet transmission rate for different scenarios and the improved results are presented. © 2018 IEEE.

IEEE 802.22 is a Wireless Regional Area Network (WRAN) anticipated at collaborating license free equipment on a non-interfering base in band that is labeled for the TV simulcast use. This standard is the fundamental authoritative for cognitive wireless that strives to tackle an empty or beneath exploit spectrum which specifically allocated for Television lines. It can cater radio band network testing spectrum that is communally earmarked to supplementary use without generating any unfair obstruction. Two dominant threats that are experienced through IEEE 802.22 are controversy of self coincidence along with the latent binding dilemma. In this paper, it furnishes a comprehensive outline of the 802.22 architecture, its demand, utilization, and conformity review that no more alone configure the ground for the depiction of this innovative mobile air network regulation, but that will also handle as base for forthcoming analysis in an encouraging circle of cognitive field.

The features of the IEEE 802.22 standard are analyzed to solve the problem of building a broadband communication channel for a remote control system for unmanned vessel. Comparative modeling of the coverage areas of the communication systems with IEEE 802.22 and IEEE 802.11 for concrete region is performed. The advantages of systems realized with IEEE 802.22 standard are shown.

Agencies from many different countries followed the footsteps of the FCC's freeing of TV white space because it provides new opportunities for the development of broadband networks. IEEE 802.22 has recommendations that can be used as guidance in the implementation of TV white space. However, the potential for disruption to the primary user is quite high. On the other hand, extensive coverage and capacity are required in the development of broadband networks, especially in rural areas. Thus, an equilibrium between the guarantee of nonintrusion and performance is essential. One of the parameters that government and service providers can use to this end is setting a radius for the TV transmitter service area and the TV white space. Therefore, we performed a simulation using the ITU-R method and path loss Hata Model to get an optimum radius combination. We found that the radius of TV white space can be elongated and shortened within a certain range. We also proposed a mathematical model to determine the variation in TV white space radius according to the simulation results.

The IEEE 802.22 system was standardized in 2011 as a fixed wireless communication system for regional area networks using TV white-spaces (TVWS). Due to its wide coverage area of 10–30 km, the IEEE 802.22 system is expected as a backbone wireless network system in developing countries as well as a public safety broadband communication system even in leading countries. This wide coverage enables a reduction of the number of base stations, resulting in the initial-cost saving compared to other communication systems. However, previously prototyped IEEE 802.22-based devices have not been deployed for social demonstrations, because there still have difficulties in cost and procurement due to the costly design such as FPGA-based baseband signal processing and specially customized RF components to comply with the strict spectrum limitations by some leading countries. In this paper, we prototype compact and lightweight IEEE 802.22-based radio equipment by applying mixed design using an FPGA and a DSP. Measured transmission spectrum conforms to Ofcom and FCC regulations with a transmit power of +30 dBm and +24 dBm, respectively. Also, measured receiver sensitivity achieves the requirement of the IEEE 802.22 system, and a maximal UDP throughput of 14.86 Mbit/s was obtained on the conditions of PHY mode 16 with a 6 MHz channel bandwidth and a 1/4 CP length.

In this paper, a new power control algorithm based on busy tone approach has been proposed for the coordination of IEEE 802.22 and IEEE 802.11af systems in TV white space. Different from the earlier studies, in addition to both 802.11af access point and clients listening to the busy tone, they also adjust their communication power according to the location information and use hopping for communication, if needed. Acccordingly, interference caused to 802.22 systems has been reduced while the 802.11af systems are still able to communicate. This study quantifies the 802.11af and 802.22 system performances in terms of interfering packet rate and succesful packet transmission rate for different scenarios considering the communication parameters and channel models adapted for the standards.

A low power integrating mixer successive approximation register (SAR) prototype chip for spectrum sensing is fabricated for portable transceivers targeting IEEE 802.22 cognitive radio applications. The integrating mixer SAR combines mixing, current-domain windowing, and integration to implement the short-time Fourier transform. Integration with programmable time constant is incorporated within the mixer by utilizing binary-weighted capacitive loads, which double as the sampling capacitors of a SAR ADC. The design operates over a frequency range of 0.05–1.25GHz, consumes 0.88mW from 1.1/1.2V supplies and obtains an average dynamic range (DR) of 25.7–27.9dB.

This paper investigates the use of deception in combating the deceiving attack in IEEE 802.22 cognitive radio networks. The deceiving attack is a coordinated combination of diverse jamming attacks sourced by the same malicious platform. In this paper, a deception-based defense scheme is proposed to counteract the deceiving attack. The non-existence of the pure strategy Nash equilibrium was proven in closed-form when the defender/attacker have the incentive to defend/attack the frequency channel. Numerical results show that irrespective of the imposed penalty on the detected attacker, the proposed defense strategies can reduce the probability of success of the deceiving attack to nearly 0%.

The IEEE 802.22, which has been standardized as a fixed communication system for a regional area network in the TV white spaces (TVWS), is expected for a backbone network in developing countries where a relatively large amount of the TVWS still exists. On the other hand, significant channel variations in the frequency domain are induced in such a wide area network because of a long- delay multi-path fading. Also, a carrier frequency offset (CFO) causes further channel variations in the time domain. In general, these channel variations are mainly compensated by the linear interpolating (and extrapolating) between reference pilot subcarrier signals. However, the number of symbols are flexible and there are some cases that cannot ensure two pilot subcarriers in the DS subframes based on the IEEE 802.22 standard. In this paper, the authors propose a simplified channel and CFO estimation scheme that can estimate channel variations symbol by symbol with using a frame preamble and several pilot subcarriers in each symbol. It was confirmed by computer simulation that an IEEE 802.22- required BER of less than 2x10^-4 can be achieved in all modulations with a CFO of +67 Hz that is defined as a maximum CFO for a signal bandwidth of 6 MHz in the IEEE 802.22 standard. In the experiment, measured BER performance indicates the same trend as the calculated BER performance, and a BER of less than 2x10^-4 can be achieved in QPSK and 16QAM. From these results, the proposed estimation scheme can be used in the long-delay multi-path fading environment.

In accordance with the global awareness and national agenda of providing digital services to the rural population of Bangladesh to improve their quality of lives, broadband internet connectivity to the remote corners of the country has been a major infrastructural concern. The purpose of this paper is to evaluate the potential of IEEE802.22 Wireless Regional Area Network (WRAN) to serve this purpose. The initial hypothesis was that due to the flat nature of terrain in most areas of the country, it would be economic to deploy WRAN infrastructure in the unused TV white spaces covering large flat areas. However, establishing Point-to-point(P2P) links might be challenging due to the same reason. To come to a concrete conclusion about the technical feasibility of this technology and an infrastructural estimate, we started this project from scratch, i.e. from designing necessary antennas, up to evaluating their coverage and P2P performance in a computer simulation tool. We have concluded that, it is possible to cover a significant amount of the country's territory using only around 25 antennas. However, to establish P2P links, the number would be higher. Hence, we conclude that wireless broadband access using WRAN, with wired or wireless backhaul, is an economic and recommended approach, where secure P2P links could also be deployed if the application of it is deemed necessary for specific purposes. The design parameters of antennas and Customer Premises Equipment (CPE) are discussed in detail in the paper.

In this paper, a new power control algorithm based on busy tone approach has been proposed for the coordination of IEEE 802.22 and IEEE 802.11af systems in TV white space. Different from the earlier studies, in addition to both 802.11af access point and clients listening to the busy tone, they also adjust their communication power according to the location information and use hopping for communication, if needed Acccordingly, interference caused to 802.22 systems has been reduced while the 802.11af systems are still able to communicate. This study quantifies the 802.11af and 802.22 system performances in terms of interfering packet rate and succesful packet transmission rate for different scenarios considering the communication parameters and channel models adapted for the standards. Turk Telekom Arcelik A S Aselsan ARGENIT HAVELSAN NETAS; Adresgezgini IEEE Turkey Sect AVCR Informat Technologies Cisco i2i Syst Integrated Syst & Syst Design ENOVAS FiGES Engn MS Spektral Istanbul Teknik Univ

This paper presents an enhanced scheme for the dynamic-frequency-hopping (DFH) technique introduced in the IEEE 802.22 standard for wireless regional area networks (WRAN). The performance of the DFH in the IEEE 802.22 standard is analysed in the presence of a Rayleigh fading channel implementing a multiple-input multiple- output (MIMO) system. We show the effect of interference caused by the Primary User (PU) appearance during the Secondary User (SU) data transmission. The system bit error rate is evaluated in order to demonstrate this effect. To overcome the limitations of the DFH on the system performance, we propose a modified spectrum sensing technique where spectrum monitoring is integrated with DFH to leverage higher throughput gains for the secondary network. The enhanced method is analyzed and simulated for a MIMO system.

Distributed power system network is going to be complex, and it will require high-speed, reliable and secure communication systems for managing intermittent generation with coordination of centralised power generation, including load control. Cognitive Radio (CR) is highly favourable for providing communications in Smart Grid by using spectrum resources opportunistically. The IEEE 802.22 Wireless Regional Area Network (WRAN) having the capabilities of CR use vacant channels opportunistically in the frequency range of 54 MHz to 862 MHz occupied by TV band. A comprehensive review of using IEEE 802.22 for Field Area Network in power system network using spectrum sensing (CR based communication) is provided in this paper. The spectrum sensing technique(s) at Base Station (BS) and Customer Premises Equipment (CPE) for detecting the presence of incumbent in order to mitigate interferences is also studied. The availability of backup and candidate channels are updated during “Quite Period” for further use (spectrum switching and management) with geolocation capabilities. The use of IEEE 802.22 for (a) radio-scene analysis, (b) channel identification, and (c) dynamic spectrum management are examined for applications in power management.

IEEE 802.22 wireless regional area networks promotes the use of TV white spaces to provide wireless broadband access to rural area using cognitive radio techniques. While selecting the best unused channel for transmission, a secondary user (SU) can use various parameters, among which the probability of appearance of the primary user (PU) in the channel. If that probability is high, the SU has to vacate the channel quickly when the PU will appear. This increases the hand-off and degrades the throughput. In this paper, the probability of appearance of a PU in a particular channel is predicted using an artificial neural network learning technique that learns the previous behavior of the PU. Simulation results are presented, showing that our proposed approach can be well fitted with the Mean Square Error (MSE) method as low as 0.08.

Cognitive Radio systems have been studied to be deployed especially in the so-called TV White Spaces (TVWS) which are defined as the TV free channels left unused in specific territorial area as direct consequence of the digital switchover plans. The IEEE 802.22 Wireless Regional Area Network (WRAN) standard has been developed to exploit the TVWS bands to assure broadband access for remote and rural areas. WRAN devices are designed to operate in the frequency range 54–862MHz alongside Digital Terrestrial Television (DTT) transmissions. This paper studies the influence of adjacent channel interference of DTT signals on IEEE 802.22 WRAN transmission. The performance of IEEE 802.22 WRAN devices in the presence of with DVB-T2 broadcasting systems is evaluated.

The Cognitive Radio (CR) is a fully-reconfigurable wireless device that can intelligently sense, manage, and exploit temporarily-vacant licensed spectrum bands during the absence of incumbent users. Broadly, the IEEE 802.22 is the first complete Wireless Regional Area Network (WRAN) standard that utilizes CR technology in the opportunistic access of white spaces in the television (TV) bands. Intrinsically, the increased CR networks' vulnerabilities alongside the experienced growth of attackers' capabilities, creates a strain on CR network designers to act accordingly. However, most of the existing efforts solely examined the issues of Denial-of-Service (DoS) attacks of IEEE 802.22 networks, such as Primary User Emulation (PUE) attack and Spectrum Sensing Data Falsification (SSDF) attack, each treated in isolation. One main challenge in CR network security domain is to efficiently represent possible simultaneous multiple security threats, and assess their effects. Unlike the previous works, this paper addresses the aforementioned challenge through using the holistic approach of assessing the combined effect of simultaneous multiple DoS attacks. The Bayesian Attack Graph (BAG) model is utilized in this paper to capture the probabilistic dependencies among IEEE 802.22 DoS threat-environment and known vulnerabilities. The simulation results indicate up to 51.3% increase in the probability of DoS in IEEE 802.22 networks considering simultaneous multiple attacks in comparison to the most severe sole attack. Finally, the paper introduces the BAG model as a feasible CR vulnerability metric that can facilitate the creation of a security tightening plan.