[LINK] The PLAN, and broadband speeds?

[George Bray]

On 6/28/07, Richard Chirgwin <rchirgwin at ozemail.com.au> wrote:

> Geostationary orbit = 35,800,000 metres
> Speed of light = 299,792,458 metres per second (in a vacuum)
>
> Two-way trip = 239 milliseconds plus a little bit for atmosphere, which
> isn't vacuum.
>
> Two two-way trips (ie, user > Internet > user) = around half a second.


That's what I found when testing one and two way satellite gear.  My
aim was to test incoming video streaming performance, so while the
delay between sending the request and receiving the stream might have
been a couple of seconds, when the stream started arriving it was
solid and reliable.

This is why I believe that the broadcast TV network could be used for
some people's regional (10-50km) internet access.  My recent
investigations show that while it's technically possible to design a
network using 80-400 Mhz, one that will give greater distance for
regional users, it would require specific development of modems. (The
existing modems I've seen aren't very modern and typically use the
slower VHF band). The expertise our country has in antenna design and
signal processing chips could be applied here, but of course the end
result is still one that uses a mobile or landline phone for the
backchannel. This network model would work to deliver ADSL1 level
speeds down, but would be a second-class solution as evolving
applications required more symmetry.

I'm on Karl's side when he laments the lack of vision for equipping
Australia properly. We should be aiming for bandwidths that won't be
considered "quaint" in a few years, compared to our neighbours.

I would have thought the importance of a national wireless BB network
would mandate some serious allocation of licensed spectrum, rather
than having it compete in the unlicensed band.

George