The switchover from analogue to digital terrestrial television (DTT), expected to be completed in Europe by the end of 2012, will free up a large amount of radio spectrum. This socalled Digital Dividend will provide a unique opportunity to meet the demand for new wireless communications services. In October 2009, the Conference of European Post & Telecommunications Administrations (CEPT) approved a number of band plans and technical conditions for the use of the 790-862 MHz Digital Dividend spectrum by mobile and fixed communications networks. These specifications are sufficiently flexible to allow FDD-only, TDD-only, or mixed frequency arrangements in this band. However, a preferred frequency arrangement based on FDD has been recommended, with the understanding that member states may implement different frequency arrangements with the aim of achieving general interest objectives, ensuring greater efficiency through market-based spectrum management, ensuring greater efficiency when sharing with existing use, or avoiding interference. In this paper we present an overview of the specified band plans and regulatory technical conditions. We also describe the methodologies behind their derivations, and discuss their implications for both DTT services and the new communication networks which will operate in the 790-862 MHz Digital Dividend band.Index Terms-Co-existence analysis, Adjacent-channel interference, Digital Dividend, Spectrum management, Block edge mask, Interference mitigation, WAPECS.978-1-4244-5188-3/10/$26.00 ©2010 IEEE This full text paper was peer reviewed at the direction of IEEE Communications Society subject matter experts for publication in the IEEE DySPAN 2010 proceedings

There is no doubt about the growing interest for the underwater acoustic communications. Among all existing applications, the objective of the Groupe d'Etudes Sous-Marines de I'Atlantique (GESMA) is to develop a sufficiently robust high data rate acoustic link, named TRIDENT. For that purpose, different kinds of information (texts, images ...) could be periodically transmitted through the acoustic channel. A realtime receiver, based on the spatio-temporal blind adaptive decisiun feedback equalizer, developed and patented by ENST Bretagne [I], was designed to cope with all perturbations induced by such harsh channels. Some sea trials have been carried out in June 2002. The first results are clearly convincing since most of the 48 sequences of 5 minutes are successfully detected by the DSP-based real-time receiver. This acoustic system allows transmission at data rates ranging from 8 to 25 kbps in horizontal configuration.

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This paper reports on a study undertaken within the CEPT SE42 project team, with the objective of deriving regulatory radiation limits which mitigate the impact of adjacentchannel interference from fixed/mobile communication network base stations (BSs) in the Digital Dividend spectrum (790-862 MHz) to digital terrestrial television (DTT) services below 790 MHz. A novel stochastic approach for the calculation of BS block-edge mask (BEM) out-of-block (or baseline) limits is presented. Results indicate that, for a typical BS in-block EIRP of 59 dBm/(10 MHz) or greater, the fraction of locations in which a DTT receiver would suffer unacceptable levels of interference does not improve significantly with a reduction in the BS BEM baseline EIRP limit below 0 dBm/(8 MHz). This is due to the finite frequency selectivity of the DTT receivers. It is also shown that for in-blockEIRPs below 59 dBm, the baseline EIRP limit should be reduced proportionately in order for the DTT location failure rate to be broadly independent of the communication network deployment geometry.Index Terms-Co-existence analysis, Adjacent-channel interference, Digital Dividend, Spectrum management, Block-edge mask.

andre.goalic@enst-bretagne. fi dbstruct: Current needs in underwater acoustic communicafion, both for civil and military applications, are eontinuouslj increasing. During ihese lost years, GESMA (Groupe d'Efudes Sous-Marines de I'AiIantique) and ENST-Bretagne developed the TRWENT system (TRLDENT : TRansmisswn de Donndes EN Temps reel This is the first real time acoustic (ink able io transmit images, tea? and data based on multichannel blind egualizaiion. In 1994, a low bit rate speech coder (5.45 kbiuj) was designed and validated for speech acoustic wave transmission in Bresi bay [lj. More recenti'y, a speech transmission was also successfully realized in July 2003 at sea, using the new GESMA-ENST-Bretagne acouslic link This paper provides Qt4 overview of this projed The c o n t d of the study and the implementation of a very low speech acoustic link are presented Last Brest harbor speech hammission euperiments (2003) are presentedThe real time horizontal acoustic link performances are evaluated Two carriers frequencies are available (20, 35 kH@. Acousiic communications for bit rule ranging fiom 6 io 20 kbps and range from 500 to 4000 m have been conducied successfuUy over several hours in shallow water environments