Those hoping to enjoy super-fast internet access care of the Australian Government’s National Broadband Network (NBN) may have a little while yet to wait. The $43 billion system, offering up to 100Mbps, is scheduled to be phased into 90 percent of Australian homes over a period of eight years.
But a taste of what it might offer is being launched in Tasmania, and as Robbee Minicola, the CEO of Hybrid TV says, it “is not about faster web browsing, or quicker emails. It is about high resolution video content delivered… onto the television”.
Hybrid TV is the company behind Tivo in Australia, so it is all about high definition video.
Hybrid SmartStreet Project
As it happens, Tasmania is the perfect place for the trial because chunks of it are serviced by the TasCOLT network, which has optical fibre to the home, and thus a potential for very high speed.
Called the ‘Hybrid SmartStreet Project’ it aims to act as a testbed for the delivery of high value video content, including TV programming and recent release movies. Participants are those already connected by optical fibre to the network, and the service will be provided to them via Tivo personal video recorders.
To date, internet-delivered video has had major limitations and it all comes down to how thick the pipe is between your home and the source of the video. That is, how many megabits per second of data can flow.
A typical broadband connection these days in Australia, usually some variation of DSL, has a rate of between 0.25 and 8Mbps, with most being towards the lower end. In practical terms, sustained throughput is usually lower than the nominal rate, especially at the higher end of this range.
If we take 1Mbps as some kind of average, what does that provide? Let’s compare it with SDTV. Most digital TV stations run at between 4 and 6Mbps for SDTV. That’s pretty much the range for DVD as well. Standard definition TV looks dreadful at 1Mbps.
That’s why YouTube videos are so small on your computer screen. On the high quality 52 inch LCD in your lounge room… well, it simply isn’t worth it.
Of course, SDTV and DVD both use the MPEG2 compression system, and things have moved on since then with the likes of VC1 and MPEG4 offering higher quality for lower bitrates. But not that much.
So for decent quality SDTV, a reliable throughput of 4 or 5Mbps is needed.
In Australia, HDTV in 1080i format runs at about 12Mbps in that older MPEG2 format. This is a practical minimum for reasonable HD quality. By contrast, Blu-ray titles are rarely encoded with an average of less than 15Mbps, and the average is typically around 22Mbps. We have seen titles averaging as high as 37Mbps!
Incredibly, some deny that bitrate matters. In the UK, the BBC HD Service recently reduced its bitrate (link will open in a new window) from 16Mbps to just under ten. Its head actually insisted that any perceived differences were simply the preconceptions of those who claimed that the picture quality had diminished (see link below).