Nº 2 2013 > Spectrum matters
The second digital dividend: Another bite for mobile?
The next World Radiocommunication Conference (WRC‑15) will be held in Geneva from 2 to 27 November 2015 and will take vital decisions for the future of wireless communications. ITU plays a key role in harmonizing the use of the radio-frequency spectrum around the world and thus enabling the greatest benefit to be extracted from this finite resource.
As noted in ITU’s report Trends in Telecommunication Reform 2013 “at the international level, ITU provides a common venue where all Member States can participate in the work of allocating spectrum for new uses and developing standards and plans that maximize the harmonized use of spectrum resource. As the top level of the spectrum allocation process, ITU thus plays a critical role in promoting harmonization among the regions of the world — ensuring that services can coexist with each other, while minimizing interference.” In this first article of a series on spectrum matters, we look at what is meant by the second digital dividend, why it is needed and how it will be implemented.
What is the second digital dividend and how will it be implemented?
At the start of the World Radiocommunication Conference in 2012 (WRC‑12), the African and Arab groups tabled proposals for a new mobile allocation immediately below the existing 800 MHz mobile band (known as the digital dividend band because it was created by migrating the analogue terrestrial television platforms which formerly occupied this band to more spectrally-efficient digital platforms). WRC‑12 concluded with a decision to create a new mobile allocation in the band from 694–790 MHz, in ITU Region 1*, which is proposed to come into force in 2015. The delay to 2015 is in order to enable the necessary technical studies to be concluded regarding the availability and assignment of the new band, before bringing the band into use.
ITU has begun a significant work programme of technical studies on two important agenda items for WRC‑15:
- Agenda item 1.1: to consider additional spectrum allocations to the mobile service on a primary basis and identification of additional frequency bands for International Mobile Telecommunications (IMT) and related regulatory provisions, to facilitate the development of terrestrial mobile broadband applications, in accordance with Resolution 233 (WRC‑12).
- Agenda item 1.2: to examine the results of ITU–R studies, in accordance with Resolution 232 (WRC‑12), on the use of the frequency band 694–790 MHz by the mobile, except aeronautical mobile, service in Region 1 and take the appropriate measures.
The allocation of the original 800 MHz band for mobile use in Region 1 was agreed at WRC‑07. Many regulators in Europe, notably in countries such as France, Germany, Italy, Spain and the United Kingdom, have since awarded the band to mobile operators in accordance with a band plan (see Figure 1) harmonized across Europe through European Commission Decision 2010/267/EC of 6 May 2010. Regulators in the rest of Europe are expected to follow suit between now and 2015. Commercial 800 MHz LTE services have been operating in Europe since late 2009 and the superior propagation characteristics of this band compared to the 2100 MHz band (hitherto the main band used for mobile broadband services in Europe) should facilitate improvements in mobile broadband coverage in rural areas, as well as better indoor coverage in more densely-populated areas.
Reasons for and against allocating the second digital dividend to mobile
The allocation (at WRC‑12) of the second digital dividend band to mobile alongside broadcasting services followed intense debate between, on the one hand, representatives of the African and Arab States and, on the other hand, representatives of the European Conference of Postal and Telecommunications Administrations (CEPT) and administrations of the Regional Commonwealth in the field of Communications (RCC). The CEPT administrations wanted to postpone a decision about this band to WRC‑15 because the 700 MHz band is heavily used for terrestrial broadcasting with, in many cases, long-term licensing arrangements in place and a desire on the part of the broadcasters to retain access to this band which could support innovative new terrestrial services in the future. The CEPT line, developed during WRC‑12 in response to the 694–790 MHz proposals, was that this was not the appropriate point to make a new allocation in the 700 MHz band and that there were a number of open technical issues that would need to be addressed before a WRC could make such an allocation.
Underlining the fact that the original agenda for WRC‑12 did not include any proposal for a second digital dividend, RCC administrations argued that any change in the allocation of frequency bands to the mobile service in the range 694–790 MHz in Region 1 would “require a review of current international agreements regarding frequency plans in border regions of States that are party to the GE06 Agreement and to bilateral and multilateral agreements on use of the band 790–862 MHz, which define the procedural and technical aspects of the use of frequencies in the UHF band by the broadcasting, mobile and other services.”
Also, RCC administrations said that no research had been done on the broadcasting service spectrum requirements nor on compatibility with aeronautical radionavigation systems. “Allocating bandwidth below 790 MHz to the mobile service would necessitate the total or partial replanning of broadcasting service frequency allocations in order to compensate for the loss of accessible spectrum, including the transfer to other frequencies of existing stations and stations under construction. Such an undertaking is by its very nature time-consuming and extremely costly,” they argued.
The situation in Europe and the RCC countries contrasts with that in Africa and in the Arab States where the 700 MHz band is relatively under-used. Few countries in the African and Arab regions have made the transition from analogue to digital terrestrial broadcasting. In addition, the fixed telecommunication networks in these regions are less developed and hence mobile services take on greater importance. Above all, many African and Arab countries already use the 800 MHz band for mobile services related to governmental applications and therefore cannot release them for IMT applications. For these reasons the proposal from Arab and African administrations was in fact a solution for them to have their “first” digital dividend.
In the end, this argument, together with a recognition that Europe is likely to need more low-frequency spectrum for mobile broadband in the future and the prospect of harmonization with other ITU Regions, for which use of the 700 MHz band for mobile services was agreed at WRC‑07 (although for a slightly different bandwidth, namely 698–806 MHz) convinced WRC‑12 to allocate the second digital dividend band to mobile (except aeronautical mobile) on a co-primary basis with other services to which this band is allocated on a primary basis, and to identify it for IMT. However, the conference agreed to delay implementation until immediately after WRC‑15 to enable the necessary technical studies to be concluded before it is brought into use.
Implementing the new 700 MHz allocation within ITU Region 1 will, however, create a number of challenges, which need to be addressed before 2015.
For many countries in Europe where digital terrestrial television services are widely used at present, releasing 700 MHz frequencies for mobile use will require a costly retune of existing networks. In some countries, this will be the second time that digital terrestrial television services have been retuned, since many networks were already replanned in order to release the first digital dividend. Although there are options to improve the capacity of digital terrestrial television networks — such as the use of MPEG‑4 coding and migration from DVB‑T (the older standard which is the most commonly used in Europe) to DVB‑T2 (the newer generation of digital terrestrial television technology) — access to sufficient UHF spectrum is still essential in maintaining existing digital terrestrial television networks and enabling services to expand (for example, by creating more multiplexes to carry additional digital channels). This is particularly the case in European countries such as the United Kingdom, Spain, France, Portugal and Italy, where digital terrestrial television is the main television viewing platform.
It should also be noted that programme making and special events currently make use of frequency gaps between UHF channels allocated for digital terrestrial television in many countries, by coordinating their transmissions with those of the television networks. Therefore, any replanning of UHF frequencies will affect the future availability of spectrum for those services, which include wireless microphones and other applications used in theatres, sporting events and media events. Without access to the 700 MHz spectrum, in addition to the 800 MHz band, the bandwidth available for PMSE use is going to be severely constrained in comparison to the spectrum previously available.
The other big challenge in making the 700 MHz band available for mobile use is to determine an appropriate band plan that will facilitate harmonization with other world regions. This is primarily because WRC‑07 allocated a slightly different 700 MHz band in other ITU regions (698–806 MHz, which overlaps with Region 1’s 800 MHz band). Mobile licenses to use the 700 MHz band were first awarded in the United States, which has adopted a band plan that divides the 700 MHz band into various paired and unpaired blocks, including a paired block (so-called “D block”) that is earmarked for use by public safety for future mobile broadband services. However, countries in the Asia-Pacific region have subsequently agreed to implement a different 700 MHz band plan, which provides 45 MHz of paired spectrum with a 10 MHz duplex gap, similar to the European 800 MHz band. Therefore, international harmonization of the 700 MHz band could be achieved, but not without detailed cooperation between the different ITU regions, given the current divergence in 700 MHz deployments between the United States and parts of the Asia-Pacific. This is illustrated in Figure 2.
Status of the technical studies
At the ITU level, the first session of the Conference Preparatory Meeting established, on an exceptional basis, a Joint Task Group 4‑5‑6‑7 (JTG 4‑5‑6‑7) to carry out the preparatory studies on WRC‑15 Agenda items 1.1 (which deals with the need for additional mobile broadband spectrum in general) and 1.2 (which deals with proposals relating to the second digital dividend in particular). JTG 4‑5‑6‑7 has so far held two meetings. The second meeting was held in Geneva on 21–28 November 2012 and involved 280 delegates and received 67 input documents including liaison statements from concerned groups, proposals for frequency bands to be studied, elements for sharing studies and proposed text for the Conference Preparatory meeting which meets twice between each WRC.
As noted in Trends in Telecommunication Reform 2013, “The IMT studies to be conducted before WRC‑15 should assist regulators in identifying spectral efficiencies (and hence the actual spectrum needed) that should be expected as a result of advances in modulation techniques, antenna designs, offloading between different radio networks, coding efficiencies etc. These studies will also indicate potential candidate bands that may be used for the next generation of broadband services.”
At the European level, the European Commission issued a mandate to CEPT in March 2013 to develop technical conditions for the introduction of wireless broadband in the 700 MHz band in the European Union (EU) while ensuring appropriate protection for incumbent uses, primarily broadcasting services and PMSE, and taking into account other priority areas of EU spectrum policy such as public protection and disaster relief. Addressing the European Radio Spectrum Policy Group shortly before the CEPT mandate was published Neelie Kroes, Vice-President of the European Commission responsible for the digital agenda said “I want to find a sustainable long-term solution for this band — that is my commitment. There is huge potential in international harmonization. So I want to avoid a fragmented approach, balance the interests of incumbent and new users, and deliver the greatest possible benefits for Europe, economically and socially.”
Benefits of the second digital dividend
Notwithstanding these challenges, the new 700 MHz band could provide a solution for African and Arab countries to award further spectrum for mobile services without disrupting existing services in the 800 MHz band. It could also provide Europe with much needed additional bandwidth for commercial mobile broadband services in the future, as well as possibly offering a solution to the needs of European public safety organizations, which are currently seeking additional spectrum for future mission-critical mobile broadband networks. Finally, it could create some low-frequency spectrum that is harmonized for mobile use across two or possibly all three ITU regions, which would facilitate roaming and create economies of scale for device manufacturers and network equipment vendors alike.
This article was prepared by ITU News and Analysys Mason, a consultancy and research firm with a focus on telecommunications, media and technology.