The spectral efficiency of the DVB-T protocol in comparison to the analog television systems will inevitably lead to the reduction of the UHF spectrum that is necessary for the current television broadcasts. Even if the number of available TV programs increases, or new services such as High Definition TV (HDTV) are introduced along with DVB-T, there will still be more available spectrum at any given area than today. The spectrum that will be released by most European countries when the full digital switchover is completed in 2012 has been designated as "digital dividend" and is a matter of controversy between broadcasters and mobile communications operators that wish to occupy part of it. This paper examines the coexistence of DVB-T and IMT-2000 mobile telecommunications in the UHF bands IV and V that are used today for television broadcasting on a primary basis. The situation in which both services operate in adjacent (or even in the same) channels is examined on both technical and regulatory grounds, so as to take into account the international standards and rules for television broadcasting and personal mobile communications, as expressed mainly by the International Telecommunications Union (ITU).

Abstract. Following the boost in popularity of online social networks, both enterprises and researchers looked for ways to access the social dynamics information and user generated content residing in these spaces. This endeavor, however, presented several challenges caused by the heterogeneity of data and the lack of a common way to access them. The SocIoS framework tries to address these challenges by providing tools that operate on top of multiple popular social networks allowing uniform access to their data. It provides a single access point for aggregating data and functionality from the networks, as well as a set of analytical tools for exploiting them. In this paper we present the SocIoS API, an abstraction layer on top of the social networks exposing operations that encapsulate the functionality of their APIs. Currently, the component provides support for seven social networks and is flexible enough to allow for the seamless addition of more.

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With the advent of DVB-T in most European countries, the European Union has decided to end all analogue television broadcasts in its member countries until 2012. This analogue switchoff, as well as the increased spectral efficiency of the DVB-T protocol will create a surplus of spectrum in the UHF band, part of which is to be used by mobile communications systems. In order for this "digital dividend" to be shared efficiently, the coexistence and interference parameters between DVB-T and other services (designated as IMT-Advanced by the International Telecommunications Union) have to be studied. In this paper a generic 5 MHz interfering signal is broadcasted in close proximity to a stationary DVB-T receiver. Various DVB-T parameters are then measured and analyzed for different frequency values and power levels of the interfering signal.