[LINK] The PLAN, and broadband speeds?

[David Lochrin]

On Friday 22 June 2007 04:44, Glen Turner wrote:
> On Wed, 2007-06-20 at 15:43 +1000, David Lochrin wrote:
>> Let's say the proposal is to replace all existing copper subscriber
>> connections with fibre of some sort.  All sorts of potential uses 
>> might be identified, but the main use would probably be TV (*).
>
> Sorry to disagree, but I've got fiber-to-the-office running at
> a gigabit and I never use it to watch TV in the traditional
> sense.

   I should have made myself clearer.

   The PLAN talks about 12 Mbit/s to most homes and businesses in the country.  The vast majority of domestic users would only need large bandwidths for TV, and there are many more domestic users than business users.  Even most businesses (e.g. the local deli) would not need high bandwidths either.  Hence the greatest use of the network as a whole would be for TV.

   There are certainly many businesses who could use high bandwidth, but they're a very small proportion of the total number of user-nodes.

> If I pull up the traffic graphs the peaks are from video
> conferencing.  This suggests that a new customer access
> network needs to have enough bandwidth planned to run high
> definition video conferencing at phone call quantities.

   For whom - the average domestic user?

> If you add it up
>  - two HD TVs
>  - two HD videoconference
>  - some web
>  - phones
> you need about 1.2Gbps -- call it 1Gbps for convenience and
> assuming you can squeeze more performance out of HD video codecs
> as CPUs improve. So we're talking fiber to the home as the end game.
> Note that high definition has a heavy use of bandwidth, without that
> you get about 60Mbps for the above list. But I've seen HD
> videoconferencing -- unlike HD TV the difference is compelling (eg,
> you can hold up a page and the other person can read it).

   Last time I looked very acceptable video-conferencing needed 0.000256 Gbit/s in each direction.  The VoIP service I use in this regional area has a voice quality which is indistinguishable from a copper service and takes about 0.000030 Gbit/s.  But in any case, you're describing a rather specialist office environment.

   Finally, there has to be some reference to cost and benefit in all this.  It might be possible to get film-quality TV resolution with sufficient bandwidth but I don't think for a moment that the taxpayer should be asked to pay for that sort of investment, especially when it would amount to a huge subsidy for media interests.

   The "utility" of a given bandwidth per Mbit/s rises at a decelerating rate with bandwidth.

David