An international study of 30 operators suggests that the channel change time on internet protocol television services can be faster than on traditional platforms such as satellite. The average channel change time across various platforms was just under two seconds, while for Microsoft Mediaroom it was around 0.6 seconds. Whether that makes any real difference to the overall user experience is another matter.

Microsoft has long promoted fast channel change as a feature of its internet protocol television platform. This demonstrates that a switched system need not necessarily be slower than a broadcast service. Indeed, connecting to a stream over a network may well be quicker than tuning to a multiplex and decoding the relevant channel.

As informitv has previously observed, it is unclear whether this is a real issue for viewers. With the move to digital television, zapping between channels has generally taken longer as a result of the way in which signals are multiplexed, compressed and buffered. However, the introduction of interactive programme guides and on screen programme information has made the identification and selection of channels and programmes much more convenient, particularly when there may be hundreds of channels available.

One might argue that the ease of navigation of the programme guide is a more significant element of the user experience than the speed with which viewers can zap through channels. That might seem to be symptomatic of something else — the inadequacy of other forms of navigation, the lack of compelling programming, or perhaps a response to interruption by advertising. In fact the speed of changing channels is a dubious benefit to broadcasters.

Nonetheless, it is easier to measure objectively the time taken to change channels. Witbe, is French company that specialises in measuring quality of experience. They sell a range of robot monitors that can measure the availability, performance and integrity of digital television services. The company studied 30 operators in 16 countries on 4 continents, with a mix of DSL and fibre broadband, cable, satellite and terrestrial television systems. Details of the individual operators were not disclosed.

Witbe found that the average channel change time using channel up and down selection was 1.9 seconds. Microsoft Mediaroom was fastest, with an average of 0.6 seconds. However, channel change times of 0.7 seconds were measured on other platforms, although it tended to take twice as long on satellite. Where the channel was selected by number, the average channel change time came out at 3.4 seconds.

So the real question is whether users are more likely to choose channels by pressing up and down buttons, by selecting them from an interactive programme guide, or entering them numerically. The former suggests a rather random grazing behaviour, while the latter are more goal oriented. It also begs the question of whether users will be more satisfied by selecting a programme by browsing through on screen information or scanning through channels visually.

While channel change time is an objective measure of technical performance of a platform, it is a hygiene factor rather than a motivator or differentiator. The reality is that what viewers really care about is the programmes.

www.witbe.net