2.2 Methodology applied for digital terrestrial television channel planning and its respective results
This section describes the methodology applied by Brazil to prepare its channel planning for the deployment of the DTTB in the country and its results. The applied methodology is independent of the DTTB standard adopted. A working group under the coordination of Anatel and representatives from the Brazilian TV networks has been working on digital terrestrial television channel planning since 1999.
When it comes to coverage, Brazilian TV networks present quite different characteristics among themselves. They can be either regional networks or national networks, which encompass regional networks, or eventually independent full TV station with strict local penetration. Figure 31 indicates the distribution of full TV stations (in stars) and relay stations (in circles) of a particular Brazilian network with distributed generation and national penetration.
The preparation of the Basic Plan for DTTB began in September 1999. Since then, specific premises have been established. They are as follows:
− digital television will replace existing analogue TV by using UHF (channels 14 to 69) frequency bands;
− the main objective of channel planning is to assure that digital television stations will have service areas similar to their corresponding analogue stations service areas;
− during the initial stage called the ‘transition period’, analogue and digital channels will perform simultaneous broadcast (simulcasting);
− digital television planning will be carried out in three phases: “Phase 1” only for those cities where active full TV stations are in place and, in a later stage; “Phase 2” for those cities whose population is over one hundred thousand inhabitants with only television relay stations; and “Phase 3” for others cities with television relay stations;
− whenever is possible, digital stations will have to operate on the maximum power of its class7.
Network with distributed generation and national penetration (Phases 1 and 2)
Because of the preparation for the Basic Plan for Digital Television Channel Distribution (PBTVD8), Anatel has suspended, from October 1999 to April 2005, allocation of new analogue channels, and changes of the technical characteristics in the existing channels in regions of Brazil under heavy spectrum usage. From February 2002 to April 2005, the same policy was applied to the remaining regions. After the publication of the PBTVD, item 1.3.3, Anatel resumed activities on the analogue channels allotment plan, proceeding with the inclusion of new analogue channels. It’s important to observe that PBTVD will continue to use the frequency band currently allocated to analogue transmission.
2.2.2 Phases of digital television channel planning
The channel plan studies were divided in three phases. The first phase focused on making digital channels available to broadcast simultaneously with a specific and already existing analogue channels, those authorized to provide television service on municipalities where at least one generator station covers.
The second phase focused on the availability of digital channels for simulcasting in municipalities with population above one hundred thousand inhabitants and that are covered only by relay stations. This phase also included a review of the first phase, in order to meet the demand in all municipalities to which authorizations to install new television operating networks were granted after the beginning of the first phase.
In the year of 2006, Brazilian government initiated the third phase of digital channel planning studies. This phase deadline is June 2011. It includes the allotment of digital channels for the relay stations on the remaining cities and a digital channel revision on the previous phases allotment plan.
2.2.3 Channel planning results
The first phase, concluded in September 2002, made available 1 151 digital channels in 164 municipalities, as presented in Fig. 32.
Digital channels available after Phase 1
The second phase, concluded in March 2003, made further allocation of 742 digital channels in
132 municipalities. As a result of the conclusion of both Phases 1 and 2, 1893 channels were made available for the introduction of Digital Terrestrial Television Broadcasting (DTTB) in Brazil as presented in Fig. 33.
Digital channels allotted after the conclusion of Phase 3
The Basic Plan for Digital Television Channel Distribution (PBTVD) has been successful in assuring that the service areas of digital television stations is similar to its related analogue stations. The PBTVD encompasses 296 Brazilian municipalities, whose total population is approximately 110 million inhabitants. These municipalities are either covered by a generator television station service or their population is over one hundred thousand inhabitants and there is, at least, one operating relay station in the city. Only in service analogue channels were taken into account for the channel planning. Therefore, up to August 2008, 2 157 digital channels have been made available by the National Telecommunications Agency (Agência Nacional de Telecomunicações - Anatel)and there will be more than 6 100 digital channels in Brazil until 2013. Thus, more than 12 200 channels, analogue or digital, will be available during the “simulcast” period from 2013 to 2016.