The EBU is surely correct though to argue that broadcasters should begin by carefully identifying the different service categories they will support before considering how best to distribute the content in each case. The EBU highlights four categories of service, each of which may enable access to either all or a subset of the broadcaster’s total content catalogue. Firstly there is the traditional linear broadcast service, which includes radio as well as TV, comprising news, shows, drama, movies and sport, delivered to a fixed schedule with no facility for change by the viewer.

Secondly come nonlinear broadcast services, still partitioned into channels but allowing the viewer to choose when to watch, as in catch up and time shifted services, as well as downloading for viewing later. Thirdly comes on-demand broadcast services, which take matters a stage further away from tradition by enabling selection of content by the item, breaking out of the ghetto of channels. Finally there are hybrid services, which are another step forward in combining both linear and non-linear elements within the same broadcast, for example by injecting second screen interaction. Hybrid services are being deployed by both traditional broadcasters and Telcos, and exemplify the need to consider the changing nature of content consumption in planning video transport. To give the best user experience hybrid services require a level of integration between broadcast and broadband right through the content lifecycle from the point of production and are driving converged services.

It is worth noting that alternative providers are no longer confined to the on demand category, but are muscling in on all four, including linear through live streaming for example. The sub text of the EBU’s document therefore is that broadcasters need to respond by exploiting their expertise in efficient and high quality video transport. In the case of hybrid services this may entail making use of digital terrestrial networks to reach mobile devices and perhaps enable higher quality than is currently possible over cellular networks, especially where 4G/LTE has yet to be deployed.

Broadcasters need to assess their roadmap in the context of these four service categories and estimate traffic volumes and quality requirements in each case. Such considerations will lead to varying conclusions, depending on the territory, reach and distribution of their audience, so that in some cases it will reaffirm a commitment to digital terrestrial, while for say a broadcaster in Africa it may even lead towards LTE Broadcast over cellular, although satellite is more likely to predominate for most. Broadcasters also need to consider the breakdown in usage levels between different access methods, which itself influences video transport strategy. There is a distinction between access from non-public areas, either the home or place of work, and transient areas such as airports or stations, with a further distinction here between terminals that are stationary and moving, as in a car or train. While the EBU may expect the home to continue to predominate, it concedes this may not always be the case and there will definitely be a continual increase in transient access, with the debate being over the rate at which this takes place. The key point here for broadcasters is that at present they generally have little control over the infrastructure for transient access but will increasingly be expected to guarantee quality and even provide help to consumers.

The EBU document proceeds to drill down in some detail into technical considerations driven by the use cases. As one example a broadcaster might decide that live streaming quality of service for each user should be totally independent of the size of the audience, just as it is with traditional broadcast, in which case some form of multicast rather than unicast approach should almost certainly be deployed.

One notable point emerging from the more detailed discussion is that broadcasters will increasingly have to address more complex multiple use cases rather than isolated single scenarios. The EBU argues that the individual user case will evolve into usage patterns, resulting for example from increased incorporation of second screens into services. This will happen on a temporal basis, where the possible actions of a user will be determined by what has just appeared on screen, like responding to an ad by clicking to purchase say, or voting in a games show. It will also happen synchronously, as when users are interacting through a mobile device while watching on the big screen. These too have implications for transport infrastructure and interaction between different access methods.

Fundamentally, the EBU paper is urging broadcasters to define carefully the set of technical requirements for each use case and from this identify the distribution option that best satisfies these. The distribution options under consideration are digital terrestrial, satellite, cable, fixed broadband and mobile broadband, while conveniently ignoring IPTV since that does not fit well with the conclusions, although in fairness this is rarely a primary medium for public service distribution in Europe.

The report’s conclusions are firstly that broadband networks are not suitable for use cases involving linear TV services, because they typically provide only best-effort quality and are in general not able to serve large concurrent audiences. However, as the EBU admits, this limitation is more pronounced on mobile networks. The suggestion that the limitation applies equally to fixed services is looking outdated.

The second conclusion is that use cases that include on-demand services are only enabled by broadband networks, since they alone provide the return channel not available on broadcast networks. However digital cable networks often do provide a return path even when they are not providing broadband service, so this does not quite fit.

Then the EBU asserts that a number of use cases are enabled by more than one distribution option, while at the same time no single option can embrace all relevant use cases. Therefore, in order to enable the whole range of relevant use cases, broadcasters need to consider multiple distribution options that complement each other. Such distribution options may be able to support multiple use cases simultaneously, as broadband networks can by enabling linear TV and access on-demand at the same time. The EBU suggests that broadband networks may not be able to meet peak demand for all supported use cases simultaneously, but it looks like that again will increasingly not be the case for fixed line services.