Abstract-The FCC in the U.S. has recently increased the amount of spectrum available for wireless broadband data services by permitting unlicensed access to television whitespaces. While this additional unlicensed spectrum allows for market expansion, it also influences competition among providers and can increase congestion (interference) among consumers of wireless services. We study the value (social welfare) obtained by adding unlicensed spectrum to an existing allocation of licensed spectrum among incumbent Service Providers (SPs). We assume a population of customers who choose a provider based on minimum delivered price. Here, delivered price is the price of the service plus a congestion cost, which depends on the number of subscribers in a band. For the model considered, we find that the social welfare depends on the amount of additional unlicensed spectrum, and can actually decrease over a significant range of unlicensed bandwidths.

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The problem of allocating bundles of indivisible objects without transfers arises in many practical settings, including the assignment of courses to students, of siblings to schools, and of truckloads of food to food banks. In these settings, the complementarities in preferences are small compared with the size of the market. We exploit this to design mechanisms satisfying efficiency, envy-freeness, and asymptotic strategy-proofness. We introduce two mechanisms, one for cardinal and the other for ordinal preferences. When agents do not want bundles of size larger than k, these mechanisms over-allocate each good by at most k − 1 units, ex-post. These results are based on a generalization of the Birkhoff-von Neuman theorem on how probability shares of bundles can be expressed as lotteries over approximately feasible allocations, which is of independent interest.

There has been growing interest in increasing the amount of radio spectrum available for unlicensed broadband wireless access. That includes "prime" spectrum at lower frequencies, which is also suitable for wide area coverage by licensed cellular providers. While additional unlicensed spectrum would allow for market expansion, it could influence competition among providers and increase congestion (interference) among consumers of wireless services. We study the value (social welfare and consumer surplus) obtained by adding unlicensed spectrum to an existing allocation of licensed spectrum among incumbent service providers. We assume a population of customers who choose a provider based on the minimum delivered price, given by the weighted sum of the price of the service and a congestion cost, which depends on the number of subscribers in a band. We consider models in which this weighting is uniform across the customer population and where the weighting is either high or low, reflecting different sensitivities to latency. For the models considered, we find that the social welfare depends on the amount of additional unlicensed spectrum, and can actually decrease over a significant range of unlicensed bandwidths. Furthermore, with nonuniform weighting, introducing unlicensed spectrum can also reduce consumer welfare.

In a limited form cellular providers have long shared spectrum in the form of roaming agreements. The primary motivation for this has been to extend the coverage of a wireless carrier's network into regions where it has no infrastructure. As devices and infrastructure become more agile, such sharing could be done on a much faster time-scale and have advantages even when two providers both have coverage in a given area, e.g., by enabling one provider to acquire "overflow" capacity from another provider during periods of high demand. This may provide carriers with an attractive means to better meet their rapidly increasing bandwidth demands. On the other hand, the presence of such a sharing agreement could encourage providers to underinvest in their networks, resulting in poorer performance. We adapt the newsvendor model from the operations management literature to model such a situation and to gain insight into these trade-offs. In particular, we analyze the structure of revenuesharing contracts that incentivize both capacity sharing and increased access for end-users.

By applying the curve‐type thin film transistor (TFT) with longitudinal strain, TFT parameters do change little down to the 2R bending. The mobility variation range reduces down to 4% compared with 28% of the line‐type channel with transverse strain. The smaller variation is preferred for a high quality display. We clarified that majority carrier's effective mass and scattering rate are dominant factors influencing the bended TFT's performance, which can be controlled by the strain orientation and channel shape. This understanding and improvement was embedded in the 5.8″ flexible QHD active matrix organic light emitting diode panel with multi edge curvature of Galaxy S8. Through this achievement, we made our flexible premium active matrix organic light emitting diode panels more performable, reliable, and highly productive in small R bending circumstance.

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