Re: Calling for free using wifi devices

"q23r" <(E-Mail Removed)> hath wroth:

>Is there any kind of software for pda, smartphones wich allows you to
>talk for free
>using voip over wifi?

There's no such thing as free anything. Someone eventually has to
pay. See, which is close to free but not quite.:
http://arstechnica.com/news.ars/post/20060722-7327.html
http://www.gizmoproject.com/learnmore-allcallsfree.html
If you're just originating calls (not receiving them), then SkypeOut
is free until the end of the year:
http://www.skype.com/products/skypeout/
Of course, VoIP calls to other VoIP users, on the same system, are
free.

>I mean not only skype like software, but e.g. software wich is not
>required any server.
>Like voip for LAN.

Not possible. At some point, your VoIP data has to interface with the
PSTN (public switched telephone network). Someone has to supply this
gateway service. You can build your own FXS (foreign exchange switch)
or Asterisk switch at home, and tie up your home POTS line with phone
calls, but I don't think that's what you want.

>What do you think is the max disctance for moblie wifi devices which is
>good enough
>for voip?

About 300ft with a good directional antenna, line of sight, and no
interference. Perhaps 50ft with a typical office or coffee shop
environment. Forget about driving down the road yacking on your VoIP
phone.

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sun, 23 Jul 2006 10:47:57 -0700, Jeff Liebermann
<(E-Mail Removed)> wrote in
<(E-Mail Removed)>:

>... Forget about driving down the road yacking on your VoIP
>phone.

Until (unless?) mobile WiMAX becomes a reality.

--
Best regards, FAQ for Wireless Internet: <http://Wireless.wikia.com>
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Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>

On Mon, 24 Jul 2006 16:00:05 GMT, John Navas
<(E-Mail Removed)> wrote:

>On Sun, 23 Jul 2006 10:47:57 -0700, Jeff Liebermann
><(E-Mail Removed)> wrote in
><(E-Mail Removed)>:
>
>>... Forget about driving down the road yacking on your VoIP
>>phone.

>Until (unless?) mobile WiMAX becomes a reality.

I think he said that he wanted to call for free.
How much does free cost?

Mobile WiMax (802.16e) was ratified by the IEEE in Dec 2005. Now, all
WiMax needs is a proven revenue model, more spectrum than the almost
worthless 50MHz the FCC released on 3.65GHz, a major chipset or
handset manufactory interested in betting the company on WiMax, a
public willing to pay for the adventure (when they can get 802.11 VoIP
service almost for free), and sufficient infrastructure to compete
with conventional cellular coverage. There are WiMax system operating
today on 2.4 and 5.7GHz (mostly using Navini hardware). They're not
free and have the same interference problems as other 2.4GHz systems.


--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558 (E-Mail Removed)
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On Mon, 24 Jul 2006 22:39:24 GMT, Jeff Liebermann
<(E-Mail Removed)> wrote in
<(E-Mail Removed)>:

>On Mon, 24 Jul 2006 16:00:05 GMT, John Navas
><(E-Mail Removed)> wrote:
>
>>On Sun, 23 Jul 2006 10:47:57 -0700, Jeff Liebermann
>><(E-Mail Removed)> wrote in
>><(E-Mail Removed)>:
>>
>>>... Forget about driving down the road yacking on your VoIP
>>>phone.
>
>>Until (unless?) mobile WiMAX becomes a reality.
>
>I think he said that he wanted to call for free.

I was just responding to your statement.

>How much does free cost?

Zero? More? Less?

>Mobile WiMax (802.16e) was ratified by the IEEE in Dec 2005. Now, all
>WiMax needs is a proven revenue model, more spectrum than the almost
>worthless 50MHz the FCC released on 3.65GHz, a major chipset or
>handset manufactory interested in betting the company on WiMax, a
>public willing to pay for the adventure (when they can get 802.11 VoIP
>service almost for free), and sufficient infrastructure to compete
>with conventional cellular coverage. ...

I think the market for Mobile WiMAX is just as compelling as Wi-Fi, and
with that kind of force behind it, I'm pretty sure any obstacles will be
overcome. Time will of course tell.

--
Best regards, FAQ for Wireless Internet: <http://Wireless.wikia.com>
John Navas FAQ for Wi-Fi: <http://wireless.wikia.com/wiki/Wi-Fi>
Wi-Fi How To: <http://wireless.wikia.com/wiki/Wi-Fi_HowTo>
Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>

John Navas <(E-Mail Removed)> hath wroth:

>>How much does free cost?
>
>Zero? More? Less?

There's no such thing as free. Someone eventually has to pay. Likely
candidates are municipalities, advertisers, coffee shops, corporate
sponsors, equipment manufacturers, and individuals.

>>Mobile WiMax (802.16e) was ratified by the IEEE in Dec 2005. Now, all
>>WiMax needs is a proven revenue model, more spectrum than the almost
>>worthless 50MHz the FCC released on 3.65GHz, a major chipset or
>>handset manufactory interested in betting the company on WiMax, a
>>public willing to pay for the adventure (when they can get 802.11 VoIP
>>service almost for free), and sufficient infrastructure to compete
>>with conventional cellular coverage. ...

>I think the market for Mobile WiMAX is just as compelling as Wi-Fi, and
>with that kind of force behind it, I'm pretty sure any obstacles will be
>overcome. Time will of course tell.

Compelling? Does that mean there's a demand for WiMax that can't be
satisfied with other technologies?

How will WiMax be sold? As an alternative to DSL/cable/satellite last
mile broadband connectivity, which seems to be what Intel is pushing?
There's not enough bandwidth to do that.

Perhaps as an alternative to Wi-Fi? I'll believe that when I see a
consumer WiMax access point (that's not a rack mount).

Perhaps as an adjunct to cellular or replacement for EV-DO? Sprint
announced in Feb 2005 that they will sell a conglomerated cellular and
WiMax handset. Then, nothing happened. I just don't see VoIP using
about 30KHz of raw packet switched data bandwidth, to do what could
what could be done with 8-12KHz of cellular circuit switched
bandwidth.

It's highly likely that if mobile data services become predominant
over voice services, then WiMax is the obvious technology to use. That
might actually happen, but at this time, I don't see it. Voice still
rules the airwaves.

Perhaps when and if Intel delivers on its WiMax roadmap of the month:
Intel to Add WiMax to Handsets in 2007
http://www.eweek.com/article2/0,1895,1643796,00.asp



--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Tue, 25 Jul 2006 09:26:11 -0700, Jeff Liebermann
<(E-Mail Removed)> wrote in
<(E-Mail Removed)>:

>John Navas <(E-Mail Removed)> hath wroth:

>>I think the market for Mobile WiMAX is just as compelling as Wi-Fi, and
>>with that kind of force behind it, I'm pretty sure any obstacles will be
>>overcome. Time will of course tell.
>
>Compelling? Does that mean there's a demand for WiMax that can't be
>satisfied with other technologies?

I think so, not readily at least:
* Wi-Fi range is too short.
* 3G is too expensive, scarce and controlled.

>How will WiMax be sold? As an alternative to DSL/cable/satellite last
>mile broadband connectivity, which seems to be what Intel is pushing?
>There's not enough bandwidth to do that.

I think there is/will be enough bandwidth as part of a mix of
technologies -- it's not an all or nothing proposition. Some will use
WiMAX for fixed last mile, particularly when cable/DSL isn't readily
available. Some will use it for mobile instead of 3G.

>Perhaps as an alternative to Wi-Fi?

As part of the mix.

>I'll believe that when I see a
>consumer WiMax access point (that's not a rack mount).

Why? I see nothing wrong with commercial providers (including folks
like Sonic.net, if they ever break out of just copying AT&T), at least
in the beginning. And Moore's Law will keep bringing down size and
cost.

>Perhaps as an adjunct to cellular or replacement for EV-DO?

As an adjunct to everything else.

>Sprint
>announced in Feb 2005 that they will sell a conglomerated cellular and
>WiMax handset. Then, nothing happened. I just don't see VoIP using
>about 30KHz of raw packet switched data bandwidth, to do what could
>what could be done with 8-12KHz of cellular circuit switched
>bandwidth.

Perhaps not, although I don't think the tradeoff is all that clear cut,
and I expect more efficient variations of VoIP to be developed in any
event.

>It's highly likely that if mobile data services become predominant
>over voice services, then WiMax is the obvious technology to use. That
>might actually happen, but at this time, I don't see it. Voice still
>rules the airwaves.

Voice is just a form of data.

>Perhaps when and if Intel delivers on its WiMax roadmap of the month:
> Intel to Add WiMax to Handsets in 2007
> http://www.eweek.com/article2/0,1895,1643796,00.asp

Intel is a good champion, lobbyist, and marketeer, but not so good at
implementation -- I see others leading that part of the charge.

--
Best regards, FAQ for Wireless Internet: <http://Wireless.wikia.com>
John Navas FAQ for Wi-Fi: <http://wireless.wikia.com/wiki/Wi-Fi>
Wi-Fi How To: <http://wireless.wikia.com/wiki/Wi-Fi_HowTo>
Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>

Jeff Liebermann <(E-Mail Removed)> writes:
> Perhaps when and if Intel delivers on its WiMax roadmap of the month:
> Intel to Add WiMax to Handsets in 2007
> http://www.eweek.com/article2/0,1895,1643796,00.asp

At one point I read that the wimax "dsl replacement" links would have
30watt transmitters.

http://www.slate.com/id/2106657/

"WiMax runs at as much as 30 watts, powering through walls with a
maximum range of 30 miles."

I've got to wonder how well a 30watt transmitter will work in the
average laptop. I can see this working well enough in a roof-mounted
system where power is available, but in a laptop where the power is
coming from a rather small battery, this is going to be a problem. I
understand there will be power control so transmitters won't waste
power whan talking to close by receivers. That is nice, but if the
whole stated advantage of wimax is that you can crank up the power to
go further, saying you have power control to turn down the power when
not needed is a cop-out. If people use their laptops to connect to a
distant wimax node, they will need to use considerable power. That
just begs the question, does wimax at the same power levels as wifi do
any better in terms of the distance it can cover at the same overall
throughput? Is there any throughput/watt advantage to wimax?

-wolfgang
--
Wolfgang S. Rupprecht http://www.wsrcc.com/wolfgang/

On Tue, 25 Jul 2006 11:52:11 -0700, "Wolfgang S. Rupprecht"
<wolfgang+(E-Mail Removed) .wsrcc.com> wrote in
<(E-Mail Removed)>:

>
>Jeff Liebermann <(E-Mail Removed)> writes:
>> Perhaps when and if Intel delivers on its WiMax roadmap of the month:
>> Intel to Add WiMax to Handsets in 2007
>> http://www.eweek.com/article2/0,1895,1643796,00.asp
>
>At one point I read that the wimax "dsl replacement" links would have
>30watt transmitters.
>
> http://www.slate.com/id/2106657/
>
> "WiMax runs at as much as 30 watts, powering through walls with a
> maximum range of 30 miles."
>
>I've got to wonder how well a 30watt transmitter will work in the
>average laptop. ...

This is for fixed WiMAX. Mobile WiMAX is different. Mobile laptop
transmitters won't need to be anywhere near that powerful.

--
Best regards, FAQ for Wireless Internet: <http://Wireless.wikia.com>
John Navas FAQ for Wi-Fi: <http://wireless.wikia.com/wiki/Wi-Fi>
Wi-Fi How To: <http://wireless.wikia.com/wiki/Wi-Fi_HowTo>
Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>

"Wolfgang S. Rupprecht"
<wolfgang+(E-Mail Removed) .wsrcc.com> hath
wroth:

>At one point I read that the wimax "dsl replacement" links would have
>30watt transmitters.

Groan. That's just like cell sites having 100 watt transmitters.
What's important is how many wants per channel (i.e. per user).
Typical for cellular is 1 watt per channel for 800MHz and I think a
bit more for 1900MHz PCS. Add in the antenna gain and it's about 10
watts per channel. The 30 watts for WiMax is probably the aggregate
power for the central access point.

> http://www.slate.com/id/2106657/
> "WiMax runs at as much as 30 watts, powering through walls with a
> maximum range of 30 miles."

Sigh. Can you say hype (or hyperbole)?

Commentary on WiMax by Andrew Seybold:
http://www.outlook4mobility.com/comm...05/aug0505.htm
http://www.outlook4mobility.com/comm...005/au1605.htm

>I've got to wonder how well a 30watt transmitter will work in the
>average laptop.

No problem as along as the optional air conditioning unit is
installed.

>That
>just begs the question, does wimax at the same power levels as wifi do
>any better in terms of the distance it can cover at the same overall
>throughput? Is there any throughput/watt advantage to wimax?

Yes, and yes. We have a local 2.4Ghz WiMax WISP operating from
Fremont Peak (and possibly Mt Toro) that does MUCH better at coverage
and reliability than other 2.4Ghz 802.11b/g WISPs on the same
mountains.

As for spectral efficiency, 802.11 is about 2.5 Mbits/sec/Hz, while
WiMax is 3.0 to 3.8 Mbits/sec/Hz. Variation is due to WiMax adaptive
modulation.

WiMax removes many of the gross inefficiencies found in 802.11. In
particular, timing issues that limited the maximum range of 802.11 are
largely eliminated. For example, the WiMax guard interval is about
1/8 the time of 802.11 and is adjustable. There's also automagic tx
power control which largely prevent interference from over powered
alligators and evil mesh wireless providers. 802.11 is stuck with
22MHz occupied bandwidth. WiMax can vary from 1 to 28MHz.

I won't pretend to understand all the differences. Some articles on
the subject:
| http://www.commsdesign.com/design_co...leID=170100162
| http://www.wirelessnetdesignline.com...leID=159402714

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

John Navas <(E-Mail Removed)> hath wroth:

>>I've got to wonder how well a 30watt transmitter will work in the
>>average laptop. ...

>This is for fixed WiMAX. Mobile WiMAX is different. Mobile laptop
>transmitters won't need to be anywhere near that powerful.

Navini's 2.4GHz Riptide MX wireless client radio is 1 watt max.
| http://www.navini.com/Website/assets..._Datasheet.pdf
Well, actually it's adjustable from -30dBm to +30dBm and probably
spends most of its time at well below the 1 watt maximum.

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558