Cognitive Radio

Bio: Cognitive Radio is an academic researcher. The author has contributed to research in topics: Cognitive radio & Spectrum management. The author has an hindex of 1, co-authored 1 publications receiving 33 citations.

Spectrum sharing using licensed shared access: the concept and its workflow for LTE-advanced networks

Abstract: Spectrum sharing between an existing incumbent spectrum user and an LTE/LTEAdvanced network with conditions that resemble exclusive licensing have become an appealing solution for mobile network operators to respond to the growing traffic and spectrum demand in a timely manner. While traditional exclusive licensing continues to be the preferred option for MNOs, the new sharing- based licensed shared access (LSA) concept is receiving growing interest in research, regulation and standardization. When applied to mobile communications, the LSA concept would allow an MNO to share spectrum from another type of incumbent spectrum user under a regulator?s supervision with predetermined rules and conditions that guarantee operational certainty for both MNO and incumbent. This article reviews different types of spectrum bands for LTE/LTE-Advanced and beyond networks, and focuses on the LSA concept as a spectrally efficient solution for spectrum access in the future. The article identifies the key stakeholders, including the incumbent spectrum user, the MNO, and the regulator, and their roles in the LSA concept. The key elements in the LSA concept are reviewed, and a work flow for the life cycle of the LSA concept is proposed, consisting of LSA preparation, licensing, deployment, and release phases. The tasks of the key stakeholders in the different phases of the LSA work flow are discussed. The LSA concept can offer a complementary approach to traditional exclusive licensing and license-exempt operations with features that benefit all involved stakeholders. It can be realized with reasonable modifications to the existing network infrastructure and regulatory framework with two new elements for managing the varying spectrum availability: the LSA Repository and LSA Controller.

On the Feasibility of Sharing Spectrum Licenses in mmWave Cellular Systems

Abstract: The highly directional and adaptive antennas used in mmWave communication open up the possibility of uncoordinated sharing of spectrum licenses between commercial cellular operators. There are several advantages to sharing including a reduction in license costs and an increase in spectrum utilization. In this paper, we establish the theoretical feasibility of spectrum license sharing among mmWave cellular operators. We consider a heterogeneous multi-operator system containing multiple independent cellular networks, each owned by an operator. We then compute the signal-to-interference-and-noise ratio and rate distribution for downlink mobile users of each network. Using the analysis, we compare the systems with fully shared licenses and exclusive licenses for different access rules and explore the trade-offs between system performance and spectrum cost. We show that sharing spectrum licenses increases the per-user rate when antennas have narrow beams and is also favored when there is a low density of users. We also consider a multi-operator system where BSs of all the networks are co-located to show that the simultaneous sharing of spectrum and infrastructure is also feasible. We show that all networks can share licenses with less bandwidth and still achieve the same per-user median rate as if they each had an exclusive license to spectrum with more bandwidth.

Live field trial of Licensed Shared Access (LSA) concept using LTE network in 2.3 GHz band

Abstract: This paper presents the results from a live field trial of the new Licensed Shared Access (LSA) concept using a TD-LTE network in the 2.3 GHz spectrum band in Finland. In the trial a live LTE network shares the spectrum from incumbent programme making and special events (PMSE) service including cordless cameras without causing harmful interference. The trial implements the new LSA concept and the required new building blocks including LSA Repository for spectrum availability information and LSA Controller for commanding the mobile communication network in the band. The trial uses a real TD-LTE base station, real network management system, and real core network. Incumbent spectrum usage data is collected to the LSA Repository and used by the LSA Controller to retrieve available spectrum bands. LSA Controller uses the network management system to configure the base station according to the spectrum availability information. Incumbent spectrum users' rights are protected by evacuating the LSA band and handing users over from the LTE network to other networks when requested by the incumbent spectrum user. Numerical results are presented to quantify the duration of the LSA band evacuation process. The demonstration shows that the new LSA concept can be implemented with existing network elements and a minimum amount of new components. The first performance results on the LSA band evacuation times indicate that the LSA band can be evacuated and released in good time and the incumbents' rights can be protected.

Database-Assisted Spectrum Sharing in Satellite Communications: A Survey

Abstract: This survey paper discusses the feasibility of sharing the spectrum between satellite telecommunication networks and terrestrial and other satellite networks on the basis of a comprehensive study carried out as part of the European Space Agency’s Advanced Research in Telecommunications Systems programme. The main area of investigation is the use of spectrum databases to enable a controlled sharing environment. Future satellite systems can largely benefit from the ability to access spectrum bands other than the dedicated licensed spectrum band. Potential spectrum sharing scenarios are classified as: a) secondary use of the satellite spectrum by terrestrial systems, b) satellite system as a secondary user of spectrum c) extension of a terrestrial network by using the satellite network; and d) two satellite systems sharing the same spectrum. We define practical use cases for each scenario and identify suitable techniques. The proposed scenarios and use cases cover several frequency bands and satellite orbits. Out of all the scenarios reviewed, owing to the announcement of many different mega-constellation satellite networks, we focus on analyzing the feasibility of spectrum sharing between geostationary orbit (GSO) and non-geostationary orbit (NGSO) satellite systems. The performance is primarily analyzed on the basis of widely accepted recommendations of the Radiocommunications Sector of the International Telecommunications Union. Finally, future research directions are identified.

Field trial of the 3.5 GHz citizens broadband radio service governed by a spectrum access system (SAS)

Abstract: In this paper, we describe a spectrum access system (SAS) based Citizens Broadband Radio Service (CBRS) field trial using a live LTE network in the 3.5 GHz band. The latest WInnForum specification guided the implementation of the relevant protocols for SAS operation. Here, we evaluate the performance of a CBRS field trial by using one of the most important performance indicators in a spectrum sharing scenario — the evacuation time. It indicates how rapidly the secondary user relinquishes the shared spectrum band to the primary user. Following the applied protocols, we measure and analyze the time scales for the evacuation and frequency change procedures in a field trial environment. Our work shows that the set time limits for the protection of primary users against interference are realistic when using commercially available mobile networks and equipment. Finally, utilizing knowledge of the latest base station models, we propose ways to reduce the evacuation and reconfiguration time by up to 70%.