DigiTAG

Web Letter

March 2010

DigiTAG seeks to inform members and non-members about important developments in the digital terrestrial television market. Each month, DigiTAG distributes its web letter with news updates and further exploration of one topic.

To subscribe to the DigiTAG Web Letter, send an email to the DigiTAG Project Office.

Introducing mobile services in Band V in Europe

As digital switchover progresses in many European countries, national administrations are considering how to allocate frequency usage in Bands III, IV, and V. While the Geneva 2006 (GE-06) Agreement established an all-digital frequency plan for broadcast services (DVB-T, T-DAB) to use these bands, some national administrations would like to allocate the upper part of Band V, specifically from 790-862 MHz, to telecom operators.

At the last World Radiocommunication Conference 2007 (WRC-07), national administrations modified the Radio Regulations, the international framework governing the use of frequency spectrum and satellite orbits, to allow for the introduction of mobile telecom services (specifically IMT applications such as 3G and 4G) in the terrestrial frequency bands from 790-862 MHz. Such an allocation is possible in Europe after 17 June 2015, which corresponds to the date ending the analogue/digital broadcast transition as established in the GE-06 Agreement, although some countries have requested the right to introduce mobile services at an earlier date.

Status in Europe

The European Commission has actively encouraged its Member-States to allocate the frequencies from 790-862 MHz for new wireless broadband services. In its recent communications COM(2009) 586/2 entitled Transforming the digital dividend into social benefits and economic growth, the Commission called on Member-States to set aside these frequencies to support the emergence of mobile telecom services using a set of harmonized technical conditions.

Already, eight national administrations (Denmark, Finland, France, Germany, Norway, Spain, Sweden, Switzerland, and United Kingdom) have announced plans to introduce mobile telecom services in the frequencies 790-862 MHz while a further eight administrations (Austria, Czech Republic, Ireland, the Netherlands, Poland, Portugal, Slovakia, and Slovenia) are considering to do so. National administrations in other countries have not yet announced any formal decisions.

The availability of these frequencies for mobile services will vary between countries. While all countries will wait until after the completion of analogue switch-off, some may be able to introduce services as early as 2010 as is the case in Sweden. Other countries, such as Spain, will wait until 2015. The situation in Spain is complicated by the current use of these frequencies for the provision of 4 national DVB-T single frequency networks which involve 2,000 transmitter towers and 3,500 gap-fillers. These DVB-T networks will need to be moved to lower frequencies before mobile telecom operators can make use of the 790-862 MHz frequency sub-band.

Protecting against interference in Europe

In introducing two-way electronic communication services in frequency bands adjacent to broadcast services, national administrations must protect broadcast services against interferences. National administrations may also seek to adopt similar technical requirements for the use of these frequencies in order to allow services to develop across a single European market and prevent market fragmentation.

Based on these objectives, the European Commission has issued a decision on the harmonised technical conditions that should be used by Member-States for electronic communication services in the frequency sub-band from 790-862 MHz. The draft version of the decision is available and is expected to be approved at the end of March 2010.

The Commission decision is based on two reports published by the CEPT, an organisation which brings together national communications regulators from across Europe. These two reports, Report 30 and Report 31, provide the technical conditions and frequency channelling arrangements for the use of the 790-862 MHz by two-way communication networks while also ensuring the protection of broadcast services. Both of these reports were drafted based on mandates issued by the European Commission.

The DVB-T protection ratios used in Reports 30 are based on measurements made of DVB-T receivers when confronted with interferences from mobile services, and specifically UMTS services. However, not all broadcast services are fully protected. Extra mitigation techniques may need to be introduced at a national level on a case-by-case basis to ensure full protection of broadcast services. These measurements used in Report 30 can be found in Report 138 which was published by the CEPT in September 2009.

As a next step, the CEPT is currently in the process of defining the protection ratios for DVB-T receivers when confronted with interferences from next generation mobile services, LTE. A first version of this report is expected to be adopted at the next CEPT meeting to be held in June 2010. The measurement results of this report may require the CEPT to make revisions to Report 138.

Interference protection work by the ITU

Work is currently underway at the ITU to further establish protection ratio values for broadcast services, whether from interference from other broadcast services or from mobile telecom services.

ITU-R BT 1368
At the International Telecommunications Union (ITU), a review is currently underway of the recommendation ITU-R BT 1368 which provides the protection ratios to guard against the interference caused to DVB-T signals. The ITU recommendation is a general ITU reference which can be used for network implementation or network coordination between countries.

Consumer electronics manufacturers have taken part in the discussions to revise ITU-R BT 1368. Fears had arisen that many of the measurement studies being considered by the ITU addressed the traditional “metal-can” tuners used in television sets rather than the “silicon” tuners that have more recently been made available. As manufacturers increasingly rely on “silicon” tuners, they want to ensure that their DVB-T receivers will resist interference.

As a result, manufacturers have requested that the ITU postpone its revision of the Recommendation ITU-R BT 1368 until further measurement studies made by manufacturers can be considered. These measurement studies, which will take into account how “silicon” tuners respond to different levels of interference, will be presented to the ITU in April and will likely impact the protection ratios used for broadcast network planning. The final version of ITU-R BT 1368 is expected to be adopted in Fall 2010.

WRC-07 study mission
One of the resolutions adopted at the WRC07 calls on the ITU to study the impact of the use of the frequencies 790-862 MHz by mobile applications and how they can impact broadcast services. This work is being undertaken by the Joint Task Group for broadcast and mobile services (JTG 5/6) which is expected to issue its report in May 2010. The report is expected to provide an overview of the conditions necessary to allow for the introduction of mobile services in the 790-862 MHz frequency sub-band without causing disturbances to broadcast services in neighbouring countries.

The JTG 5/6 report will subsequently be presented at the next World Radio Conference, to be held in early 2012, at which time national administrations may decide whether or not it is necessary to take regulatory measures to ensure the protection of broadcast services.

Source: Natalie Mouyal, DigiTAG Project Office

About DigiTAG

DigiTAG aims to encourage and facilitate the implementation and introduction of digital terrestrial television services using the Digital Video Broadcasting Project's Standard (DVB-T). It has some 60 members from broadcasting, network operators, regulatory, and manufacturing organisations throughout Europe and beyond.

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