Translation with SYSTRAN Links

Cohabitation of the DVB with the mobile networks of 4th generation

Photograph flickr: nickstone333

The implementation of the digital dividend, made possible by the stop of analogical hertzian television (completed with the national plan on November 30th, 2011) and the terrestrial passage on television digital (DVB), made it possible to transfer part of the audio-visual spectrum, the band known as of the 800 MHz (791-862 MHz), towards the telephone services mobile. This created a situation of new cohabitation between mobile networks of fourth generation (4G-LTE [1]) and services of the DVB. This cohabitation of two networks, structures very different and on blocks from contiguous frequencies, can punctually disturb the reception of the DVB.


An experimentation in the zone of Saint-Etienne

In order to anticipate the possible consequences of the implementation of the 4G bandages of them 800 MHz on the reception of the DVB, and to work out an industrial process of accompaniment of the televiewers likely to be scrambled, a representative experimentation was to be carried out. This operation was carried out, on the initiative of the minister in charge of the digital Economy, by the operators of mobile telephony in link with the higher Council of audio-visual (CSA), the national Agency of frequencies (ANFR), the Authority of regulation of the electronic communications and stations (ARCEP), the Directorate-General of the media and cultural industries (DGMIC), the Directorate-General of competitiveness, industry and services (DGCIS), the prefecture of the Loire, the community of agglomeration Saint-Etienne metropolis, the town hall of Saint-Etienne and the town halls of 21 communes located in the coverage area of the relays 4G-800 MHz. Several companies also made their contribution: the French federation of télécoms (FFT), chains of the DVB represented by the companies operators of multiplexing, companies ensuring their diffusion in the zone concerned, the common subcontractor of the three operators for the implementation of the remediation on the spot, like several fitters of antennas established in the urban area.

The town of Saint-Etienne and its urban area were in particular selected because of their representativeness in terms of population, of cover of the DVB, structure even of network DVB and frequencies DVB in service. The first two experiments had already proceeded in Laval between October 2011 and January, of which one in urban environment, in the presence of a consortium made up of TDF, Alcatel-Lucent, Orange, SFR and Bouygues Telecom. This experimentation could highlight the impact of emissions 4G-LTE in the band of the 800 MHz on the DVB, without make it possible to learn all the lessons necessary to an industrial deployment in particular having to integrate a process of protection of the reception of the DVB, taking into account the low number (eight) of lit stations 4G-LTE.

A more complete and thorough experimentation was thus considered starting from the mid-2012 by the three operators of mobile telephony, the ANFR, the CSA and the ARCEP. The town of Saint-Etienne was retained by the whole of the representatives and the experimentation took place between August 2013 and April. The methods of the experimentation were defined while being based in particular on the decree n° 2012-951 of August 1st, 2012 and the decision n° 2011-0599 of May 31st, 2009 of the ARCEP which fixes the rules and the responsibilities related to the remediation in the event of jammings for the DVB.

In margin of the preparation of the experimental pilot deployment tri-operators in Saint-Etienne, experiments mono-operator were also carried out by SFR in Lyon, then Orange in Toulouse and Bouygues Telecom in Montpellier and Bordeaux. At the conclusion of these deployments in pilot phase, a commercial opening was envisaged by the mobile telephone operators.


In the event of jamming, a phone number

The cases of jammings indexed during these various experiments were in the near total of the cases related to the saturation of the equipment of reception. Indeed, the proximity of a transmitter of telephony 4G of a reception DVB can cause a “dazzling” of the latter. In certain very rare cases, a non-observance of the report of protection, i.e. the relationship between the useful level of signal and the level of the signal jammer, could involve a jamming of the DVB. The solution adopted in the event of proven jammings is the installation of a filter adapted to the level of the installation of reception of the hearth concerned. The televiewers, whose audio-visual reception is subjected to an interference with a telephone relay, must initially make known themselves near the call center of the National agency of the frequencies, whose phone number is the 09 70,818,818 (reachable some 8 a.m. Monday to Friday to 7 p.m. at the cost of a local call). Moreover fuller explanations on the processes retained for this new cohabitation of the DVB with the telephony of 4th generation are detailed on space Internet


[1] Long Term Evolution