D-Book 12.6: DTT Requirements for Interoperability


The requirements for interoperability for the first terrestrial television service to launch in the world were set out by industry in the DTG D-Book in 1996. This exceptional cross-industry collaboration continues to reflect innovation in technology and market needs with a new annual edition. It is uniquely implemented across the entire distribution chain, from playout through to the television, set-top box or recorder.

Principally, and in the interests of international harmonisation, the D-Book references international technical standards. Where these are unavailable or not yet stable, the DTG publishes full UK technical requirements in advance of contribution, where appropriate, to the relevant international standards development organisation by the DTG or one of its members. Where it is later possible to reference an ETSI or other standard in subsequent editions the specific D-Book section will be simplified.

As a set of critical implementation guidelines, the D-Book ensures that there is a wide choice of consumer electronics devices available in the market from a range of international manufacturers.

DTG Testing is an independent industry test facility that allows manufacturers to have products verified for interoperability against the D-Book. DTG Testing supports the consumer electronics sector by ensuring device interoperability at the prototype stage. It continues this support when receivers are sold, by testing new services across receivers in the DTG Zoo; a fully connected and operational receiver collection.

As the complexity of the platform increases, the importance of interoperability and conformance against tests is greater than ever. Good interoperability underpins the ongoing success of Freeview and Freeview Play.

The D-Book has successfully supported the introduction of HD, DVB-T2 as well as the clearance of the 700 MHz band – which was completed in August 2020 (but note that, for the time being, one DTT multiplex continues to use channel 55, part of the 700 MHz band ‘duplex gap’).

Past editions of the D-Book introduced HbbTV references for Freeview Play and the MHEG to HbbTV transition. In addition, support for HEVC and HDR for IP delivered services was introduced.

The D-Book continues to support the development of products and services, including enhancements to coexistence testing; defining the profile of UHD; supporting compatible receivers for broadcast; and bringing the HbbTV requirements up to date with recent work by the HbbTV Association and DVB.

D-Book 12 removed requirements that were no longer needed for the evolution of DTT platforms, such as SD receiver profiles. This evolution continued in D-Book 12.5, mainly reflected in the “SI Rules of Operation” chapter and an update of the Errata of the HbbTV Specification. In addition, an overhaul of the structure improved navigation throughout the document and an effort to unify language and layout.

With the latest update to 12.6, D-Book continues the collaboration with HbbTV and DVB by updating the HbbTV requirements to the latest 2.0.3 specification. HbbTV support becomes a mandatory requirement, marking a new stage in the MHEG to HbbTV transition.

The DTG welcomes contributions from members on the evolution towards hybrid distribution systems which will feed into the development of future D-Books. The DTG continues to ensure European and international harmonisation wherever possible while meeting the needs of the rapidly developing and highly successful UK TV market.

DTG members can download the D Book here.