Spectrum sharing in the gray space

There has been considerable effort to let more wireless devices operate in white space spectrum, that is within frequency bands and geographic areas where no wireless devices are active. Making white space available is certainly useful, but there are other sharing opportunities as well, some of which have been obscured by dangerous misconceptions about the concept of unused spectrum. This paper discusses allowing more devices to operate safely in gray space spectrum, that is spectrum that is actively being used in that transmissions are underway—something many economic models assume is impossible. The paper focuses on primary–secondary sharing, so devices gaining access to spectrum operate on a secondary basis in a way that never causes harmful interference to primary systems. Examples of primary–secondary gray space sharing mechanisms are described in which devices are allowed to share spectrum with broadcasting, radar, and cellular systems. Quantitative analysis shows that it is technically possible to support significant communications among secondary devices in spectrum that is already heavily used by cellular or radar. However, gray space sharing generally causes primary and secondary systems to be more technically interdependent than white space sharing, so different policy and governance structures are needed. Secondary market rules can support gray space sharing in cases where there is a single primary spectrum user, such as a cellular carrier. In cases where technology is static, the regulator may be able to control access for secondary devices. However, in cases with multiple primary users and multiple secondary users of spectrum, as might be seen in bands with radar for example, a new kind of governance body will be needed to facilitate spectrum sharing.     

An optimal way to licence the radio spectrum

Radio spectrum licences are generally specified in terms of the power a holder is allowed to transmit. However, if licences become flexible, allowing change of use and technology, then this licensing approach could result in significant interference between users. A new approach is proposed termed “spectrum usage rights” (SURs) which restricts the interference a licence holder is allowed to cause rather than the power they are allowed to transmit. This approach is shown to protect users against interference while providing the maximum flexibility possible and its implementation is discussed.     

Will 5G lead to more spectrum sharing? Discussing recent developments of the LSA and the CBRS spectrum sharing frameworks

This paper discusses two recent spectrum management frameworks, the Licensed Shared Access (LSA) developed in Europe and the Citizens Broadband Radio Services (CBRS) developed in the United States (US), which build their management approach on spectrum sharing. The importance of these two frameworks, besides their leading normative roles, is that recent debates have shaped them as cases to consider in the adoption of the upcoming fifth generation (5G) of mobile communications technology, in particular in the C-band. A discussion on these two frameworks is organised by following the four-step decision-making guide for spectrum management developed by Pogorel (2007), which requires spectrum authorities to make decisions in four areas of spectrum management: frequency harmonization, technology standardization, type of usage rights and assignment procedures.Notwithstanding the similarities with respect to the four areas of spectrum management considered, the two frameworks differ on their implementation schedules. CBRS leads the way, with a handful of providers receiving government approval to manage spectrum access controllers, and as of mid 2020, scheduled to have allocated spectrum licenses on half of its available spectrum. On the contrary, European countries have shown scarce interest towards implementing the LSA, despite the extensive work carried out by regulatory and standardization bodies.This may suggest that there are external contextual factors which influence the successful implementation of spectrum sharing frameworks. An interesting aspect which deserves further investigation is the institutional context in which decisions related to radio spectrum management are taken. Unlike the US authorities, European institutions do not possess coercive enforcement powers with respect to spectrum sharing. This key difference may contribute to explaining the different speed at which LSA and CBRS are implemented.     

The spectrum policy reform paving the way to cognitive radio enabled spectrum sharing

The increasing amount of data and video traffic carried by mobile networks has recently risen the demand for enhanced network capacity, more efficient use and more effective management of spectrum. Cognitive radio technologies candidate to respond to these urgent needs by allowing a near simultaneous band sharing. The regulation plays a crucial role in promoting the adoption of these technologies, in order to overcome the traditional paradigms of authorizations for exclusive spectrum usage. The article outlines spectrum management regimes where the implementation of frequency sharing technologies, including cognitive technologies, is foreseeable and brings them back to a comprehensive taxonomy of dynamic spectrum access and sharing models, in the effort to reconcile partially diverging approaches and nomenclatures suggested in literature. Theoretic analysis is supported by a number of illustrations and practical experiments with shared spectrum usage. Based on suggested taxonomy, the research aims at showing the evolutionary path toward the introduction and spreading of cognitive and other spectrum sharing technologies, pointing out relevant trends and instruments made available by the reform of EU Telecom Package, as well as at outlining the status of regulation, policy and standardization in Europe.     

Economic viability of private commons: Framework and guidelines for profitability

Ongoing regulatory reforms have led to several novel spectrum sharing models under the general umbrella of dynamic spectrum sharing. The private commons model introduced by FCC in 2004 allows spectrum licensees to provide secondary access to spectrum on an opportunistic basis while retaining ownership. Since wireless communication systems are typically overprovisioned in order to deliver service-level guarantees to (primary) users under short-term load variations, this model bears significant potential by facilitating utilization of temporal and spatial surplus of capacity through serving secondary users at possibly different service levels. A potential barrier to adoption of the private commons model is the uncertainty about secondary price–demand relationship which is difficult to predict in an emerging market: A selected price for secondary access may be profitable for some values of secondary demand but not for others, leading to a profound uncertainty about ultimate benefit of spectrum sharing. This paper aims to eliminate such an uncertainty by devising concrete guidelines and methods for profitability. The paper establishes that the price of secondary spectrum access can be chosen to guarantee profitability for any value of secondary demand: It is shown that for both the coordinated and uncoordinated commons regimes a profitable price should exceed a threshold value, which can be calculated. Hence profitability of private commons is insensitive to the demand function. This observation has two complementary interpretations: From a business perspective it provides a constructive approach to profitability; and from a regulatory perspective it provides reassurance that private commons is a healthy model. The paper also leverages the insensitivity property and outlines a technique to further enhance revenue via iterative spectrum offerings.     

Dynamic usage of narrowband spectrum

We examine the potential for expansion of the white space spectrum sharing model in the 400 MHz band. As opposed to UHF broadcast spectrum, which contains unassigned or idle segments known as white spaces, the 400 MHz band is characterised by intensive licence usage. However, productive spectrum usage does not guarantee allocative efficiency, which would require knowledge of the highest value service for each licence. 400 MHz frequencies are not priced on opportunity cost. It is therefore difficult to ascertain the economically efficient mix of services to deploy in the 400 MHz band. Drawing parallels with the high-economic value revealed and generated through the operations of unlicensed white space devices in UHF broadcast spectrum, we identify untapped 400 MHz spectrum capacity, which we refer to as narrowband spaces. Encouraging dynamic spectrum usage of narrowband spaces could, similarly to TV white space usage help realise the efficient allocation of the 400 MHz band. However, the narrowband nature of the 400 MHz licences and high licensing turnover imply a significantly different concept of dynamic spectrum access than that considered for TV Bands. The paper discusses regulatory implications and the type of services suited to exploit narrowband spaces.     

Transmitters and receivers' investment to avoid interference: Is there an optimal regime?

The management of interference has been, and still is, the main concern in spectrum policy. Historically, interference has been dealt with by heavy regulation under an administrative control regime. Over the last decades, a new approach has been put forward based on users' property rights, better able to cope with a rapidly changing technological environment. The issue of dealing with interference across bands, however, remains crucial: What obligations should be put on users so as to keep interference at a socially acceptable level? Also, given that some unwanted emissions are bound to occur, how can private parties be provided with the right incentives to invest in high-quality reception technology? This paper assesses how well different regulatory regimes can lead to efficient outcomes. It develops an economic model of spectrum interference and identifies the efficient solution. A regime where spectrum users have the power to enjoin intruding emissions beyond a predefined level (property rights protection) is compared with a regime where users are forced to bear with intruding emissions, but are entitled to economic compensation for the harm suffered (liability rules protection). The analysis suggests that different regimes may perform differently under different circumstances depending on the cause of interference and, critically, on whether the services are organised as an open- or a close-architecture system. This suggests that regulators should pay more attention to the specific features of the different bands, and that the appropriate spectrum management regime should be designed to recognise these differences.     

A dynamic policy license for flexible spectrum management

Electromagnetic spectrum for wireless communications is fully allocated by regulatory authorities, but this does not mean that it is fully utilized. Demand for greater capacity and new services requires new regulatory and technical models for spectrum sharing. This paper develops a regulatory model denoted the dynamic policy license. The dynamic policy license combines the assurances to licensees that come from holding a fixed license while maintaining regulatory flexibility. A dynamic policy license is similar to a traditional spectrum license that specifies a bandwidth, power, center frequency, location, and other parameters. However, one or more of these parameters is subject to change by the regulator over time. The allowed changes are restricted by the license to provide assurances and predictability to the licensee. The opportunities and challenges that this presents to both regulators and licensees is described. For instance, the dynamic policy license can be a regulatory tool for more aggressive spectrum sharing.     

A typology of business usage center members

Repurchase in business-to-business settings is driven by relational outcomes like satisfaction. Recent research suggests that these are mainly determined by the customer perceived value in use, which stems from the customers' experiences within the usage of products and services. This usage usually takes place in multi-actor usage processes, which encompass a multitude of interactions between the users of a focal resource, the members of a business usage center. These users typically perceive the processes and interactions differently depending on their position, responsibilities, expertise, mood, etc. As the actors follow various multiple goals on the individual and collective levels, they perceive the value in use of the same product or service typically differently. Thus, understanding the interactions during organizational usage processes is crucial for grasping the peculiarities of value cocreation in business-to-business usage processes. Hence, we develop a typology of business usage center members through 20 interviews using repertory grid technique and means–end chaining. We elicit five types of users based on 32 characteristics of perceived behaviors in organizational usage processes: Lead, Doer, Soldier, Maven, and Laggard. Furthermore, we show how the characteristics and types influence the actors' value-in-use perceptions and their behaviors toward a focal resource and their co-workers.     

A multilevel analysis of the role of interactional justice in promoting knowledge-sharing behavior: The mediated role of organizational commitment

Knowledge sharing behavior has received increased attention in the context of business due to its important role in enhancing organizational competitive advantage. This study aimed to identify possible predictors of knowledge sharing behavior and its underlying mechanisms from a multilevel perspective. The results showed that interactional justice positively related to knowledge sharing behavior both at the individual and the team levels. And organizational commitment took a mediated role between them. This study is the first to highlight the role of organizational commitment and interactional justice in knowledge sharing behavior, enriching current understanding of organizational knowledge management and providing further suggestions as how managers can improve knowledge sharing behavior in their organizations.     

On-line spectrum auctions in TV white spaces for supporting mobile services—A practical manual

This paper considers an approach for dynamic short-term spectrum leasing in TV white spaces (TVWS) using an on-line auction. The secondary spectrum market discussed here is organized by a central entity called the spectrum broker. The auctioned spectrum appears in blocks of available DVB-T channels with some transmit power constraints set-up to protect the primary users (DVB-T receivers). The bidders are institutional spectrum operators (telecommunication companies or service providers), operating in a given area. These players are characterized by heterogeneous demands concerning the spectrum bandwidth, the operation period with temporarily-exclusive rights for using the spectrum and the transmit power needed for successful transmission. Thus, the auctioned objects are non-identical and present different value for different players. Two auction models are proposed. The first one is the simultaneous auction in time domain and combinatorial in frequency and power dimension. The second proposed auction is fully combinatorial. Simulations results are also provided showing effectiveness of the analyzed auctions (high spectrum utilization ratio) and relation between the players’ satisfaction, their spectrum valuation and varying competition. Finally the guidelines concerning the spectrum auctions in TVWS for the policy makers are proposed.     

Spectrum auctions: Distortionary input tax or efficient revenue instrument?

Spectrum license auctions are widely recognized by economists as more efficient than lotteries or administrative approaches to allocate exclusive rights to spectrum. But whether spectrum auctions are the most efficient spectrum policy still generates debate, in part because the answer may vary depending on exactly what is being optimized, what else is assumed or held constant, and the policies to which one is comparing spectrum auctions. This paper examines the complex confluence of US spectrum policy and fiscal policy. It concludes that economically efficient spectrum policy requires several distinct optimizations, including devolvement of an efficient set spectrum rights and the optimal approach to raising and recycling government revenue in that devolvement process. It also requires allocation policies that take into account possible distortions of the secondary market for spectrum via the capital gains tax. The paper argues that there is no compelling theoretical case or empirical evidence that spectrum auctions are distortionary, and examines cases in which the most efficient policy is to auction spectrum and “recycle” the revenue to offset more distortionary revenue instruments. This paper also examines cases in which it is most efficient to allocate spectrum rights without raising revenue, for example when transactions costs are high or distributional concerns can prevent or delay efficiency-enhancing reforms.     

Mechanisms to incentivise shared-use of spectrum

A key concern with the Licensed-shared access (LSA) approach currently being developed by European regulators is that leaving incumbents and secondary users to agree to bilateral arrangements may be insufficient to incentivise an optimal level of sharing.We propose an efficient auction mechanism to incentivise incumbent users to offer shared access to the spectrum they use. The mechanism consists of two stages. In the first stage, LSA licences are auctioned. In the second stage, the incumbent is provided with a choice of either granting access under an LSA agreement to the winner of the auction or not. If the incumbent accepts, its existing licence fee is reduced, whereas, if it rejects, its existing licence fee is increased. The change in the licence fee is such that a rational incumbent always opts to share when it is efficient to do so, i.e. when the cost of sharing is below the value to the secondary user.We also explore how this simple mechanism can be extended to situations in which there is more than one incumbent in a band. Our proposed approach involves package (combinatorial) bidding and linear reference prices.     

Spatio-temporal spectrum modeling: Taxonomy and economic evaluation of context acquisition

Much of the research in dynamic spectrum access (DSA) has focused on opportunistic access in the temporal domain. While this has been quite useful in establishing the technical feasibility of DSA systems, it has missed large sections of the overall DSA problem space. This paper argues that the spatio-temporal operating context of specific environments matters to the selection of the appropriate technology for learning context information. It identifies twelve potential operating environments and compares four context awareness approaches (on-board sensing, databases, sensor network, and cooperative sharing) for these environments. In order for operators, regulators, and users to be interested in deploying DSA based networks, the expected costs should be in proportion to what the users are realistically willing to pay for services. Consequently, it is important to conduct cost analysis for different DSA approaches in parallel with the technical research. Regulators and major stakeholders should pay attention to the operating environment of DSA systems when determining which approaches to context learning to encourage.     

Roaming in the Mobile Internet

With the acquisition of UMTS licenses Mobile Operators (MOs), have often been obliged to deploy 3G network infrastructures covering at least a given percentage of users by a given date. This paper discusses the rationale for imposing these minimum coverage requirements by regulatory bodies. To that end, a model is built, which studies the incentives for MOs to compete for market share and over coverage within an unregulated environment where MOs are assumed to be free to enter sharing agreements and to negotiate a reciprocal roaming charge. Within this framework, it is first shown that MOs would deploy their infrastructure to guarantee the coverage of the entire territory (population), but they would avoid any network duplication in order to maximize rents from roaming revenues. It is then discussed whether a minimum coverage requirement is the best policy to reduce these excess rents, or whether alternative measures could be adopted which could serve other goals as well, such as the avoidance of network duplication.     

International roaming in the EU: Current overview,challenges, opportunities and solutions

As technology evolves and globalization continues, the need for reasonably priced roaming services has never been higher. In 2007, the European Commission (EC) introduced a first set of regulatory decisions to cap the maximal roaming fee end users have to pay for voice services. In the years after, additional price caps have been introduced for SMS and data, initially only for end users, in a later stage also for the wholesale tariff. The final step, Roaming Like at Home (RLAH), will start to take effect in June 2017; from then on end users will pay the same price (for voice, SMS and data) when roaming like in their domestic country.The effect of RLAH on the business case of each mobile operator is hard to predict, as the different national markets are extremely heterogeneous and operators face large discrepancies in terms of roaming usage and network costs due to different travelling patterns and various other reasons that cannot be harmonized (geography, economics, working force, usage history, etc.). Furthermore, competition in the telecom market will no longer be a purely national matter, as the decision to abolish roaming tariffs will fully open up cross-border competition.This paper aims at providing insights in the effect of RLAH for both the end user as well as the mobile operators. Following a literature survey approach, including an overview of the roaming regulation process from 2007 up to now, the paper discusses possible effects the RLAH initiative might trigger, going from lower wholesale prices for mobile operators to higher retail prices for end users. Additionally, as the European Commission strives for a digital single market, this paper presents a number of technical solutions (carrier portability, software-based SIMs, cross-border IMSI, Roaming like a Local, Wi-Fi offloading) that may pose a - partial or full - alternative for roaming and explains how these may impact cross-border competition both positively and negatively. The solutions are assessed against two axes: (1) generating the best possible outcome for the end customers (in all countries) and (2) ensuring the best level playing field for (virtual) mobile operators in Europe, which will of course involve trade-offs on different levels.     

The role of humor usage on creativity,trust and performance in business relationships: An analysis of the salesperson-customer dyad

Using humor wisely is known to have many benefits in a work-related setting. Despite these potential benefits, there is limited research on this phenomenon in a business-to-business selling context. In light of this absence, the authors introduce a theoretical model explaining the role of humor usage in a salesperson-customer encounter. Specifically, the purpose of this paper is to examine the simultaneous influence of salesperson humor usage on creativity and customer trust, which in turn affect objective sales performance. Using 149 salesperson-customer dyads from a cross-industry survey, the results indicate that (1) salesperson humor usage positively influences salesperson creativity and customer trust, (2) which in turn mediates the influence of humor on objective sales performance. In addition, (3) customer trust also influences word-of-mouth propensity and expectation of relationship continuity. The article's broader contribution is that humor usage may be a fundamental human ability that is central for enhancing creativity and developing strong relationships in a business-to-business setting.     

Determinants of Location for General Purpose Office Firms within Medium Size Cities*

This study examines determinants of the downtown/non-downtown location choice for general purpose rental office users. It presents a model of location choice which accounts for linkages, personnel commuting costs and location of market centroid. It fits the model to survey data on office space usage, distinguishing between market oriented and non-market oriented firms. The study finds that market oriented firms are primarily sensitive to market location, while non-market oriented firms are more sensitive to linkages and personnel commuting costs. It also finds that linkages play a limited role in the location decisions even for non-market oriented offices because, in the medium size cities studied, few firms are linkage intensive.     

Me and you and everyone we know: An empirical analysis of local network effects in mobile communications

This paper investigates the importance that consumers assign to local network effects, i.e. the extent to which they take account of their contacts’ mobile operators when choosing a provider for themselves. The authors identify individual characteristics that affect the importance consumers attach to local network effects. The study relies on a survey of 193 Italian students. The results show that consumers are highly heterogeneous with respect to the importance they give to the operators chosen by their friends/family members in choosing which provider to use. This heterogeneity is associated with individual innovativeness and patterns of mobile phone usage. For instance, consumers who are more interested in local network effects are typically more-aware users, who use voice services quite intensively. These consumers, who pay attention to local network effects, spend comparatively little proportional to the intensity of their mobile usage.