Why do some of you keep non-arguments about WiFi/VoIP without GSM? At
no point have I said I talked about having WiFi/VoIP without GSM.
And why do you keep making moot points about the technical problems
of WiFi on a mobile device when many such devices already have it and
Neo will eventually have it too?
Renaissance Man
On 18 Jan 2007, at 4:53 pm, <[EMAIL PROTECTED]>
<[EMAIL PROTECTED]> wrote:
I work for BT, who have been trying to get WIFI VoIP working for
_YEARS_. It's very, very difficult and has lots of problems:
1) As several other people have mentioned, the first problem is
coverage. A typical access point will only have 50m - 100m of
coverage.
2) There's no guaranteed RF bandwidth (On GSM you get a dedicated
chunk of bandwidth just for you which no-one else can use). On
Wifi, everyone shares the available RF bandwidth, which is usually
<11Mbs.
3) The backhaul network (i.e. the internet) is fairly unreliable as
far as VoIP is concerned. GSM networks usually have a circuit
switched backhaul like SDH, so again, guaranteed bandwidth. There
are IP QoS solutions out there, but there difficult to implement
well. Having said all that, it is far, far better than it was.
4) Most access points are usually connected using ADSL. The 'A' bit
of ADSL is the problem here. VoIP requires a lot of upload
bandwidth, which ADSL doesn't provide.
5) Most access points have firewalls meaning VoIP has to tunnel
through them using HTTP, confusing any backhaul QoS (How can the
network tell the difference between your time-critical VoIP call
and someone downloading a 4GB DVD image?)
6) Again as people have pointed out, a roaming Wifi contract is
very, VERY expensive (e.g. £40 per month)
7) Power. Even the low power wifi chipsets are very power hungry. I
guess you could argue that during a call, GSM draws a fair bit of
power but it's nowhere near that of a wifi chipset. GSM actively
changes its power output so it only uses what it needs to reach the
base station. Although the more advanced Wifi chipsets can also
change their power output, it's not done very well and typically
only have 3 power settings (including on and off!). I use Marvel's
88W8385 chipset which is designed specifically for mobile
applications and have been very disappointed with its power
consumption. I guess with a regular Lithium Ion/Polymer phone
battery you'd be lucky to get 30 minutes of talk time. When it
comes to standby however, the power requirements of wifi don't drop
too much whereas GSM drops to almost nothing. GSM Idle really is
amazing. All a hand unit needs to do is transmit a short keep-alive
every few minutes to let the last station know it's still there.
Like I say, BT has been working on this for ages and DO have a
solution: BT Fusion (http://www.bt.com/btfusion/). It uses your own
home/work access point if your in range, then switches to BT
OpenZone access points, then drops to GSM if your not covered by
WiFi. I think there's also some magic to move you onto GSM if you
move out of range of Wifi DURING a call.
BTW: I have absolutely nothing to do with Fusion development and am
probably wrong about all of its features. This information is my
own personal understanding of the technology and is not supported
by BT whatsoever.
Cheers,
Tom
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:community-
[EMAIL PROTECTED] On Behalf Of Andreas Kostyrka
Sent: 18 January 2007 16:05
To: Renaissance Man
Cc: [email protected]
Subject: Re: Neither iPhone or OpenMoko are revolutionary
* Renaissance Man <[EMAIL PROTECTED]> [070118 12:36]:
On 18 Jan 2007, at 10:22 am, Attila Csipa wrote:
On Thursday 18 January 2007 10:01, Renaissance Man wrote:
The problem with the Nokia E Series, N80s, and Windows
smartphones is that they're either very expensive and/or they
don't actually make VoIP via WiFi easy.
Why should they risk? They are selling millions of handsets
through carriers, and they sure don't want to lose those contracts.
And, as is often the case, someone else's risk is another's
opportunity.
All your arguments against WiFi on the Neo seem a little moot, as
it's pretty clear from what people are saying that it will have
WiFi; it's just a matter of time.
I just wish it had been on the first model because I would have
had all my needs fulfilled. As it stands I'm in the market for
something else now, and may even end up with an iPhone if
Apple includes VoIP via WiFi before OpenMoko. I wish this not just
for my own selfish reasons but because I'd like to see an open
product like OpenMoko bet out a closed product like
I don't think so. You seem to have missed the detail, that iPhone will
be offered this year on one (1!!!!) US network this year. They don't
even say if it's GSM or not. (Probably.) They have not yet told with
which networks they intend to cooperate in Europe. Even if it's GSM,
there is no telling if they will work on other GSM networks:
*) frequencies are different in the US as in Europe.
*) the data part of the phone might depend upon network details. E.g.
a Sidekick won't work on a different network. Well the voice part
will, because they tend to be not-simlocked, but all the advanced data
services won't, as the exact configuration is burned into the
firmware, which is carrier specific.
So the chances are good that OpenMoko phones will have WiFi before the
iPhone will be available in the UK are pretty good *g*
Andreas
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