Enforcement and Spectrum Sharing: Case Studies of Federal-Commercial Sharing

To promote economic growth and unleash the potential of wireless broadband, there is a need to introduce more spectrally efficient technologies and spectrum management regimes. That led to an environment where commercial wireless broadband need to share spectrum with the federal and non-federal operations. Implementing sharing regimes on a non-opportunistic basis means that sharing agreements must be implemented. To have meaning, those agreements must be enforceable.\ud \ud With the significant exception of license-free wireless systems, commercial wireless services are based on exclusive use. With the policy change facilitating spectrum sharing, it becomes necessary to consider how sharing might take place in practice. Beyond the technical aspects of sharing, that must be resolved lie questions about how usage rights are appropriately determined and enforced. This paper is reasoning about enforcement in a particular spectrum bands (1695-1710 MHz and 3.5 GHz) that are currently being proposed for sharing between commercial services and incumbent spectrum users in the US. We examine three enforcement approaches, exclusion zones, protection zones and pure ex post and consider their implications in terms of cost elements, opportunity cost, and their adaptability

Performance Analysis of Full Duplex D2D in Opportunistic Spectrum Access

© 2018 IEEE. Opportunistic Spectrum Access (OSA) allows an efficient use of spectrum based on share-it or use-it principle and can be a viable solution for the challenging problem of spectrum scarcity. Emerging systems have been proposed for OSA, where primary users (PU) have guaranteed interference protection from secondary users (SU). The potential of Full Duplex (FD) and Device-To-device (D2D) technologies in 5G has proven to be promising for increasing data rates and network capacity. In this article using stochastic geometry and random graphs, we model and assess the D2D operations in full Duplex/half Duplex mode for SUs, while protecting the PU's transmission by defining the exclusion zone (EZ). Depending on the location and transmit power of D2D users, the induced aggregate interference should not violate the interference threshold for EZ of PUs. For this, we characterize the interference from D2D links and derive the probability for successful D2D users for half-duplex and full duplex modes. Analyses is further supported by extensive simulations results

ASCENT: A Context-Aware Spectrum Coexistence Design and Implementation Toolset for Policymakers in Satellite Bands

This paper introduces ASCENT (context Aware Spectrum Coexistence Design and Implementation) toolset, an advanced context-aware terrestrial satellite spectrum sharing toolset designed for researchers, policymakers, and regulators. It serves two essential purposes (a) evaluating the potential for harmful interference to primary users in satellite bands and (b) facilitating the analysis, design, and implementation of diverse regulatory policies on spectrum usage and sharing. Notably, ASCENT implements a closed-loop feedback system that allows dynamic adaptation of policies according to a wide range of contextual factors (e.g., weather, buildings, summer/winter foliage, etc.) and feedback on the impact of these policies through realistic simulation. Specifically, ASCENT comprises the following components (i) interference evaluation tool for evaluating interference at the incumbents in a spectrum-sharing environment while taking the underlying contexts, (ii) dynamic spectrum access (DSA) framework for providing context-aware instructions to adapt networking parameters and control secondary terrestrial network's access to the shared spectrum band according to context aware prioritization, (iii) Context broker to acquire essential and relevant contexts from external context information providers; and (iv) DSA Database to store dynamic and static contexts and the regulator's policy information. The closed-loop feedback system of ASCENT is implemented by integrating these components in a modular software architecture. A case study of sharing the lower 12 GHz Ku band (12.2-12.7 GHz) with the 5G terrestrial cellular network is considered, and the usability of ASCENT is demonstrated by dynamically changing exclusion zone's radius in different weather conditions

CBRS Spectrum Sharing between LTE-U and WiFi: A Multiarmed Bandit Approach

The surge of mobile devices such as smartphone and tablets requires additional capacity. To achieve ubiquitous and high data rate Internet connectivity, effective spectrum sharing and utilization of the wireless spectrum carry critical importance. In this paper, we consider the use of unlicensed LTE (LTE-U) technology in the 3.5 GHz Citizens Broadband Radio Service (CBRS) band and develop a multiarmed bandit (MAB) based spectrum sharing technique for a smooth coexistence with WiFi. In particular, we consider LTE-U to operate as a General Authorized Access (GAA) user; hereby MAB is used to adaptively optimize the transmission duty cycle of LTE-U transmissions. Additionally, we incorporate downlink power control which yields a high energy efficiency and interference suppression. Simulation results demonstrate a significant improvement in the aggregate capacity (approximately 33%) and cell-edge throughput of coexisting LTE-U and WiFi networks for different base station densities and user densities

Interference-aware multi-hop path selection for device-to-device communications in a cellular interference environment

Device-to-Device (D2D) communications is widely seen as an efficient network capacity scaling technology. The co-existence of D2D with conventional cellular (CC) transmissions causes unwanted interference. Existing techniques have focused on improving the throughput of D2D communications by optimising the radio resource management and power allocation. However, very little is understood about the impact of the route selection of the users and how optimal routing can reduce interference and improve the overall network capacity. In fact, traditional wisdom indicates that minimising the number of hops or the total path distance is preferable. Yet, when interference is considered, we show that this is not the case. In this paper, we show that by understanding the location of the user, an interference-aware routing algorithm can be devised. We propose an adaptive Interference-Aware-Routing (IAR) algorithm, that on average achieves a 30% increase in hop distance, but can improve the overall network capacity by 50% whilst only incurring a minor 2% degradation to the CC capacity. The analysis framework and the results open up new avenues of research in location-dependent optimization in wireless systems, which is particularly important for increasingly dense and semantic-aware deployments

Analyzing Usage Conflict Situations in Localized Spectrum Sharing Scenarios: An Agent-Based Modeling and Machine Learning Approach

As spectrum sharing matures, different approaches have been proposed for a more efficient allocation, assignment, and usage of spectrum resources. These approaches include cognitive radios, multi-level user definitions, radio environment maps, among others. However, spectrum usage conflicts (e.g., "harmful" interference) remain a common challenge in spectrum sharing schemes. In particular, in conflict situations where it is necessary to take actions to ensure the sound operations of sharing agreements. A typical example of a usage conflict is where incumbents' tolerable levels of interference (i.e., interference thresholds) are surpassed. In this work, we present a new method to examine and study spectrum usage conflicts. A fundamental goal of this project is to capture local resource usage patterns to provide more realistic estimates of interference. For this purpose, we have defined two spectrum and network-specific characteristics that directly impact the local interference assessment: resource access strategy and governance framework. Thus, we are able to test the viability in spectrum sharing situations of distributed or decentralized governance systems, including polycentric and self-governance. In addition, we are able to design, model, and test a multi-tier spectrum sharing scheme that provides stakeholders with more flexible resource access opportunities. To perform this dynamic and localized study of spectrum usage and conflicts, we rely on Agent-Based Modeling (ABM) as our main analysis instrument. A crucial component for capturing local resource usage patterns is to provide agents with local information about their spectrum situation. Thus, the environment of the models presented in this dissertation are given by the REM's Interference Cartography (IC) map. Additionally, the agents' definitions and actions are the results of the interaction of the technical aspects of resource access and management, stakeholder interactions, and the underlying usage patterns as defined in the Common Pool Resource (CPR) literature. Finally, to capture local resource usage patterns and, consequently, provide more realistic estimates of conflict situations, we enhance the classical rule-based ABM approach by using Machine Learning (ML) techniques. Via ML algorithms, we refine the internal models of agents in an ABM. Thus, the agents' internal models allow them to choose more suitable responses to changes in the environment

Spectrum Sharing and SAS-CBSD Interface Simulation

Spectrum Sharing technologies enables more dynamic spectrum management regulation and framework to provide capacity for the ever-increasing demand of mobile data traffic. This thesis reviewed the background and current state of the development of Spectrum Sharing approaches. TVWS, LSA and CBRS were examined in detail as the most representative solutions. The thesis compared architectural similarities and differences between LSA and CBRS. The thesis reviewed SAS-CBSD interface protocol and continued with a practical validation of SAS-CBSD interface specification. By implementing the interface in Python, interface simulation was conducted via the assistance of automation scripts. The thesis concluded that the SAS-CBSD interface is functioning as designed, noting that ESC will further extend the spectrum access dynamism. The thesis also pointed out the need to specify SAS-relevant data models for database API standardization

Socio-technical considerations for Spectrum Access System (SAS) design

Spectrum Access Systems (SAS) are emerging as a principal mechanism for managing the sharing of radio spectrum. The design of the SAS depends on the specification of spectrum property rights and the governance system by which those rights are enforced. Current perspectives on SAS design have been too limited, focusing narrowly on the technical components without adequate consideration of socio-technical factors that will impact the likely success of any SAS design. In this paper, we apply the social science literature on the management of common pool resources (CPR) to the design challenge for the SAS. Heretofore, too much of the discussion has focused on an overly simplistic characterization of the spectrum rights design space as a dichotomous choice between licensed v. unlicensed, markets v. government, and exclusive v. open. The CPR framework forces consideration of a wider class of design options, positioning the specifications of spectrum property rights more appropriately along a multi-dimensional continuum of rights bundles. The CPR framework highlights the importance of considering formal and informal, multi-layered institutional and market-based interactions among SAS stakeholders when designing a resource management system. We will explain how this leads one to view the SAS as a polycentric governance system (using the terminology in the CPR literature). By examining the economic and social context of spectrum sharing, we assert that these emerging systems must be sufficiently flexible to adapt to various forms of resource governance, which refers to the process by which rights are distributed among stakeholders, how those rights are enforced, and how the resource is managed. We illustrate how the insights from the CPR literature might be implemented in a prototype SAS architecture

Intelligent spectrum management techniques for wireless cognitive radio networks

PhD ThesisThis thesis addresses many of the unique spectrum management chal- lenges in CR networks for the rst time. These challenges have a vital e ect on the network performance and are particularly di cult to solve due to the unique characteristics of CR networks. Speci cally, this thesis proposes and investigates three intelligent spectrum management tech- niques for CR networks. The issues investigated in this thesis have a fundamental impact on the establishment, functionality and security of CR networks. First, an intelligent primary receiver-aware message exchange protocol for CR ad hoc networks is proposed. It considers the problem of alleviat- ing the interference collision risk to primary user communication, explic- itly to protect primary receivers that are not detected during spectrum sensing. The proposed protocol achieves a higher measure of safeguard- ing. A practical scenario is considered where no global network topology is known and no common control channel is assumed to exist. Second, a novel CR broadcast protocol (CRBP) to reliably disseminate the broadcast messages to all or most of the possible CR nodes in the network is proposed. The CRBP formulates the broadcast problem as a bipartite-graph problem. Thus, CRBP achieves a signi cant successful delivery ratio by connecting di erent local topologies, which is a unique feature in CR ad hoc networks. Finally, a new defence strategy to defend against spectrum sensing data falsi cation attacks in CR networks is proposed. In order to identify malicious users, the proposed scheme performs multiple veri cations of sensory data with the assistance of trusted nodes.Higher Committee For Education Devel- opment in Iraq (HCED-Iraq