[sclug] Wireless Broadband in Slough and Windsor areas

[Simon Huggins]

Salut !

On Sat, May 22, 2004 at 11:27:27PM +1000, Roland Turner wrote:
> after Simon wrote:
> >> The prices seem similar (well ok, a little less) and the area they
> >> are targetting gets ADSL already.  I'd have thought you might have
> >> lower latency over ADSL than wireless.
> Simon didn't explain his reasoning, but it occurs to me that he (or
> others) may be confusing the high-latency experienced in satellite
> (particularly geostationary satellite) service compared to wired/fibre
> service with higher latency in wireless services in general.
> (Apologies in advance if I'm mistaken.)

I've seen a friends wireless in Cambs which has a higher standard
deviation for latency admittedly it can be better than the ADSL they've
now got but frequently it was lots worse and they had problems with
packet loss.

I guess it might be easier to provide a better service in an urban area
then through the fens but I'm not convinced just yet :)

> A bigger issue is the technology used to control shared access to the
> medium: TDMA, CDMA and other similar schemes typically used by mobile
> telephony introduce no latency. CSMA/CD (Ethernet) and the like
> (802.11*) do introduce local latency which increases rapidly with
> sustained increases in local traffic beyond about 80% of available
> local capacity.

This is presumably part of the reason my friend's connection was latent
at peak times.

> Wireless providers using 802.11* and wired providers using CSMA/CD
> (e.g. broadband IP over cable) are both susceptible to this (but N.B.
> when I lived in Montreal I was able to sustain 8Mb/s transfers over
> cable... With cable, the limiting factor tends to be the choices made
> by the carrier, not the technology itself).

Yeah again a friend of mine in Norwich has an NTL cable modem on a cable
segment which seems to get saturated with the obvious implications for
latency.  The same happened to me with NTL in Nottingham in a student
area.  It was reasonable when everyone was asleep or during holidays but
got congested quite rapidly at other times.

I'm sure a lot of this is down to the companies involved though and not
the technology.  I've seen a cable modem on NTL's network in Farnborough
which had no problems whatsoever (and was used by a gaming freak so he
would have complained ;)).

> Netvigator claims not be using WiFi bandwidth - it claims to have
> seperately licensed spectrum - but it's website lacks clues about the
> technology in use. The nett result is that we can't infer much about
> latency simply from the fact that they are wireless.

Do products exist then that do mobile phone style multiplexing for
wireless ethernet to cut off the above "sharing the airspace" problems?

> I'll be watching them with interest.

Yeah likewise.  It'd be nice if there were more options for good
connectivity.  The ADSL boom was interesting but you're still tied to
BT.  Anything that gets BT to reduce their prices for such services or
even encourages others to put in wireless/wired IP services has to be a
good thing for Joe Public.

Simon.

-- 
oOoOo "Une tasse d'eau chaude avec un nuage de lait je vous prie"  oOoOo
 oOoOo          - Jolitorax -- Ast?rix chez les Bretons.          oOoOo
  oOoOo                                                          oOoOo
          htag.pl 0.0.22 ::::::: http://www.earth.li/~huggie/