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n many countries, sharing has become a significant approach to problems of spectrum allocation and assignment. As this approach moves from concept to reality, it is reasonable to expect an increase in interference or usage conflict events between sharing parties. Scholars such as Coase, Demsetz, Stigler, and others have argued that appropriate enforcement is critical to successful contracts (such as spectrum sharing agreements) and Polinsky, Shavell, and others have analyzed enforcement mechanisms in general. While many ex-ante measures may be used, reducing the social costs of ex-ante enforcement means shifting the balance more toward ex-post measures. Ex post enforcement requires detection, data collection, and adjudication methods. At present, these methods are ad hoc (operating in a decentralized way between parties) or fairly costly (e.g., relying on the FCC Enforcement Bureau). The research presented in this paper is the culmination of an NSF-funded inquiry into how and what enforcement functions can be automated. 

Cooperative wireless networks, enabled by Cognitive Radios, facilitate mobile users to dynamically share access to spectrum. However, spectrum bands can be accessed illegitimately by malicious users. Therefore, the success of dynamic spectrum sharing relies on automated enforcement of spectrum policies. While the focus has been on ex ante spectrum enforcement, this work explores new approaches to address efficient ex post spectrum enforcement. The main objective of this work is to ensure maximum coverage of the area of enforcement and accurate detection of spectrum access violation. The first objective is achieved with the help of Lloyd's algorithm to divide the enforcement area into a set of uniformly sized coverage regions. The interference detection accuracy is achieved through crowdsourcing of the spectrum access monitoring to volunteers, based on their computational capabilities, location attributes and reputation. A simulation framework was developed in CSIM19 (C++ version) to analyze the performance of the proposed system over the entire area of enforcement. The results show that the proposed scheme ensures efficient coverage of all the channels and regions in the area of enforcement and a high average accuracy of detection. 

Abstract The exploitation of radio-electric spectrum bands for wireless transmission purposes has some features of the commons: it is subject to congestion and conflict without rules governing its use. The Coasean approach is to assign private property rights to overcome the tragedy of the spectrum commons. The process of assigning these rights is still centralized, with governments assigning property rights through agencies such as the Federal Communications Commission and National Telecommunications and Information Administration in the USA. We consider the possibility of self-governance of the spectrum. We use insights from the study of common pool resources governance to analyze the emergence of property rights to spectrum in a ‘government-less’ environment in which norms, rules, and enforcement mechanisms are solely the product of the repeated interactions among participants in the network. Our case study considers the spectrum-sharing arrangement in the 1,695–1,710 MHz band. Using agent-based modeling (ABM), we show that self-governance of the spectrum can work and under what conditions it is likely to improve the efficiency of the allocation of property rights. 

The success of dynamic spectrum sharing in wireless networks depends on reliable automated enforcement of spectrum access policies. In this paper, a crowdsourced approach is used to select volunteers to detect spectrum misuse. Volunteer selection is based on multiple criteria, including their reputation, likelihood of being in a region and ability to effectively detect channel misuse. We formulate the volunteer selection problem as a stable matching problem, whereby, volunteers' monitoring preferences are matched to channels' attributes. Given a set of volunteers, the objective is to ensure maximum coverage of the spectrum enforcement area and accurate detection of spectrum access violation of all channels in the area. The two matching algorithms, Volunteer Matching (VM) and Reverse Volunteer Matching (RVM) are based on variants of the Gale-Shapley algorithm for stable matching. We also propose two Hybrid algorithms, HYBRID-VM and HYBRID-RVM that augment the matching algorithms with a Secretary-based algorithm to overcome the shortcomings of the individual vanilla algorithms. Simulation results show that volunteer selection by using HYBRID-VM gives better coverage of region (better by 19.2% when compared to threshold-based Secretary algorithm), better accuracy of detection and better volunteer happiness when compared to the other algorithms that are tested. 

Enforcement, adjudication, and litigation enacted by the Federal Communications Commission (FCC) resides at an interesting intersection between traditional law and normative common property resource agreements – similar to those in common pool resources. Despite being granted specific legal powers by Congress, the FCC works to dissolve contentions that arise between spectrum incumbents through market dispute resolutions mediated through their Enforcement Bureau’s Market and Dispute Resolution Division (MDRD). The MDRD mediates and adjudicates a myriad of complaint types brought on by “market participants, entities, and organizations against common carriers, commercial and mobile data service providers, and/or utility pole operators” (EB-Market Disputes and Resolution Division, n.d.). The MDRD’s decision to promote resolutions between complainants and defendants is unique in terms of traditional enforcement mechanisms – especially as a primary regulatory agency. The initiative to have stakeholders mediate, negotiate, and ultimately settle their disputes on their level is reminiscent of dispute remediation tactics observed in common pool resource environments. To investigate this approach to enforcement, adjudication, and litigation further, we utilize the Institutional Analysis and Development (IAD) Framework developed by Elinor Ostrom. Used to scaffold a myriad of policy, regulatory, and traditional CPRs, the IAD Framework incites a unique investigation into the agreements that arise between disputing parties. 

Traditionally, spectrum allocation has been governed by centralized schemes (e.g., command-and-control). Nonetheless, other mechanisms, such as collaborative enforcement, have proven to be successful in a variety of scenarios. In Collaborative enforcement (i.e., collective action), the stakeholders agree on decision-making arrangements (i.e., access, allocation, and control of the resources) while being involved in monitoring the adherence to the rules as a shared effort. Blockchain is a distributed ledger of records/transactions (i.e., database) that brings many benefits such as decentralization, transparency, immutability, etc. One of the most notable characteristics of blockchain-based platforms is their definition as trust-less environments, as there is no central entity in charge of controlling the network interactions. Instead, trust is a group effort, achieved through repeated interactions, consensus algorithms, and cryptographic tools; therefore, converting blockchain systems into examples of collaborative governance regimes. In this paper, our goal is to analyze a particular application of blockchain and smart contracts for the 1695-1710MHz sharing scenario. In this way, we provide a theoretical analysis of the feasibility and the required characteristics to implement such a system. In addition, through the implementation of a Proof of Concept, we explore how the implementation of a blockchainbased organization can be the motor to build a collaborative governance scheme in the spectrum sharing arrangement of the 1695-1710MHz band 

To address the scarcity of spectrum, FCC mandated the dynamic sharing of spectrum among the different tiers of users. The success of spectrum sharing, however, relies on the automated enforcement of spectrum policies. We focus on ex post spectrum enforcement during/after the occurrence of a potentially harmful event, but before/after an actual harm has occurred. The major challenges addressed by us are to ensure maximum channel coverage in a given region of enforcement, accurate and reliable detection of enforcement, and selection of an efficient algorithm to select entities for detection of violation. We adopt a crowdsourced methodology to monitor spectrum usage. We ensure maximum coverage of the given area by dividing it into equal-sized regions and solve the enforcement problem by a divide and conquer mechanism over the entire region. We use a variant of the Multiple Choice Secretary algorithm to select volunteers. We finally simulate the enforcement framework and analyze the results. 

As radio spectrum sharing matures, one of the main challenges becomes finding adequate governance systems and the appropriate enforcement mechanisms. Historically, these processes were assigned to a central entity (in most cases a governmental agency). Nevertheless, the literature of Common Pool Resources (CPRs) shows that other governance mechanisms are possible, which include collaboration with a private, thirdparty regulator or the complete absence of central institutions, as in self-enforcement solutions. These alternatives have been developed around well-known CPRs such as fisheries, forests, etc. As argued by Weiss et al [50], and other researchers, spectrum can indeed be considered to be a CPR. In this work we study the two extremes of governance systems that could be applied to spectrum sharing scenarios. Initially, we study the classical centralized scheme of command and control, where governmental institutions are in charge of rule-definition and enforcement. Subsequently, we explore a government-less environment, i.e., a distributed enforcement approach. In this anarchy situation (i.e., lack of a formal government intervention as defined by Leeson [29]), rules and enforcement mechanisms are solely the product of repeated interactions among the intervening agents. For our analysis, we have selected the spectrum sharing framework of the 1695-1710MHz band. We also use the definitions presented by Bhattarai et al. [9], [10] as well as Altamimi [3] for managing the size of the coordination and exclusion zones. In addition, we utilize Agent-Based Modelling (ABM) to analyze the applicability of these governance mechanisms. ABM simulation allows us to explore how macro phenomena can emerge from micro-level interactions of independent agents.