Is this possible? Using a WiFi card for 2 connections?

I am trying to use the WiFi card in my Toshiba Portege M400 TabletPC to
connect to the Internet while simultaneously connecting to a WiFi
enabled projector so I can surf the web while also broadcasting the
data to the projector. We just purchased a bunch of these computers and
Panasonic wireless enabled projectors for a school and I need to
determine if this can be done before we buy more. I have received no
help from either Panasonic or Toshiba on this. I understand that every
computer and and projector is different, however, generally:

1.) Does anyone know if this is even possible to do with one Wifi card
(have 2 simultaneous different connections -- to the Internet and a
projector)?

2.) Has anyone done anything like this before?

3.) Will the connection speed be significantly slower with 2
connections?

Thanks!!!!

On 13 Jan 2007 13:38:10 -0800, "mick" <(E-Mail Removed)> wrote:

<snip>
>
>1.) Does anyone know if this is even possible to do with one Wifi card
>(have 2 simultaneous different connections -- to the Internet and a
>projector)?
>
Maybe if you wrote some custom firmware.. Anything is possible...

As it stands now, you cannot connect to two things at once.

Even with custom firmware it might not be possible. You'd have to either switch
between two different frequencies (channels) or try to talk to two devices using
the same frequency, and that would be interference.

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

>I am trying to use the WiFi card in my Toshiba Portege M400 TabletPC to
>connect to the Internet while simultaneously connecting to a WiFi
>enabled projector so I can surf the web while also broadcasting the
>data to the projector. We just purchased a bunch of these computers and
>Panasonic wireless enabled projectors for a school and I need to
>determine if this can be done before we buy more.

Model number of the projector please? While you're at it, model
number of any wireless devices, such as the access point or router,
that you're using to connect to the internet. They're not all the
same and it's much easier to answer question if I have a clue what the
[deleted expletive] you currently own.

General hint on how to get sane answers:
1. What are you trying to accomplish? (One line is fine).
2. What do you have to work with? (Hardware, software, versions).

>I have received no
>help from either Panasonic or Toshiba on this. I understand that every
>computer and and projector is different, however, generally:

Fine. You're embarrassed with your purchase or you want to turn this
into an ordeal process. Any reason to ask a general question for what
I consider to be a rather specific applications problem?

>1.) Does anyone know if this is even possible to do with one Wifi card
>(have 2 simultaneous different connections -- to the Internet and a
>projector)?

See:
<http://research.microsoft.com/netres/projects/virtualwifi/default.htm>

>2.) Has anyone done anything like this before?

Yes. I don't recall which company offered a similar feature. It was
used as a form of seamless roaming. If I can find or remember the
name, I'll post. Note that none of these allowed for mixing
infrastructure mode and ad-hoc mode as you apparently are trying to
do. I don't know of any way to do that with one wireless client card
in the laptop.

>3.) Will the connection speed be significantly slower with 2
>connections?

No. I didn't do much benchmarking, but it didn't seem to be much
slower. However, it doesn't matter. Wireless is a shared media
system. You're sharing airtime between two devices. If your
projector is doing a screaming media presentation while trying to
browse the internet, you're going to see a sharing of bandwidth
between these two applications. If you're serious about doing this, I
stongly suggest you check if your unspecified router has QoS or
bandwidth management features to insure that one or the other
application will not saturate all your internet bandwidth. However,
that will not prevent airtime sharing, which will result in a
substantial slowdown when both connections are active, and no slowdown
when one or the other is idle.

>Thanks!!!!

Not yet. You're possibly doing it wrong. The Wi-Fi enabled projector
is probably a wireless client, not an access point. As a wireless
client, it connects to your access point, not the other way around. If
you're moving data from the computer to the projector, it's much
easier to go through the access point than to go direct. Of course,
there will be a maximum speed slowdown as the access point does the
store and forward thing. Therefore, one of the devices (tablet PC or
unspecified model projector) will require a CAT5 cable to the access
point or router.

--
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

Jeff Liebermann <(E-Mail Removed)> wrote in
news:(E-Mail Removed):

> "mick" <(E-Mail Removed)> hath wroth:
>
>
> Not yet. You're possibly doing it wrong. The Wi-Fi enabled projector
> is probably a wireless client, not an access point. As a wireless
> client, it connects to your access point, not the other way around. If
> you're moving data from the computer to the projector, it's much
> easier to go through the access point than to go direct. Of course,
> there will be a maximum speed slowdown as the access point does the
> store and forward thing. Therefore, one of the devices (tablet PC or
> unspecified model projector) will require a CAT5 cable to the access
> point or router.
>

Jeff, I pointed this gentleman to this group, as his post was originally in
another group.

My assumption was that the projector was just another client, so you should
be able to do as he wants, as it's just another node on the network when
it's a regular client.

I didn't even consider an ad-hoc connection.

DanS <(E-Mail Removed)> hath wroth:

>Jeff Liebermann <(E-Mail Removed)> wrote in
>news:(E-Mail Removed) :
>> Not yet. You're possibly doing it wrong. The Wi-Fi enabled projector
>> is probably a wireless client, not an access point. As a wireless
>> client, it connects to your access point, not the other way around. If
>> you're moving data from the computer to the projector, it's much
>> easier to go through the access point than to go direct. Of course,
>> there will be a maximum speed slowdown as the access point does the
>> store and forward thing. Therefore, one of the devices (tablet PC or
>> unspecified model projector) will require a CAT5 cable to the access
>> point or router.

>Jeff, I pointed this gentleman to this group, as his post was originally in
>another group.

You should have warned him that I become rather irate when I don't get
my daily does of model numbers.

The local skool purchased a wireless projector of some sorts and
immediately complained that it was slower than a snail. A little
reading of the manual showed that it had two possible modes, ad-hoc
and infrastructure. The default was ad-hoc. The manual blundered on
to explain that this was the preferred mode because it did not suffer
from the store and forward performance loss of the infrastructure
mode, where all the packets have to go through the wireless access
point. I solved the problem by running CAT5 from the wireless router
to the projector.

I also blundered into a model that I couldn't fix this way. Toshiba
something.... digging.... TLP-T500. The piece of junk has two PCMCIA
slots, that would take some strange 802.11b only card and/or a memory
card. No ethernet available. I was stuck with about 1.5Mbits/sec
thruput, which worked amazingly well for Flash and Power Point
presentations, but absolutely sucked for video. I got fed up and
arranged for a fairly cheap RGB to NTSC/SVideo converter. The image
quality was kinda marginal, but it was good enough.

>My assumption was that the projector was just another client, so you should
>be able to do as he wants, as it's just another node on the network when
>it's a regular client.

Agreed. I think I mumbled something about that, including the
limitations on performance and sharing air time. I don't think he'll
be happy with this arrangement. I've dealt with it for convention and
hotel meeting room shared internet. The problem is when the users
arrive, turn on their laptops, Windoze boots, connects to the
internet, and a half dozen programs insist that this is the most
opertune to update their bloated applications. At two hotel systems,
I have the router ACL set to block the microsoft Windoze update site
from the conference room and am seriously tempted to impliment a proxy
server that only allows specific services. Even with some site
blocking, it still takes about 15 minutes for the internet to become
usable after everyone's laptops automatically downloaded email,
updated virus scanners, and updates everything. Never mind the moron
that runs a live webcam from the conference back to some reflector.

The skool system runs the risk of similiar problems. I don't expect
them to be as severe, but they will certainly be present. Downloading
and update during a wireless video presentation will bring the
presentation to a stuttering halt. A simultenous connection implies
that everything is on the same RF channel. The only hope is if the
wireless link for the projector will be a different channel (1, 6, 11)
from the wireless router. That implies either two different networks,
ad-hoc, or two cards in each Tablet PC, all of which are a complicated
mess.

>I didn't even consider an ad-hoc connection.

Ad-hoc is the preferred mode for high speed point to point
performance. Ask any wireless game freak. With wireless video (which
is what I presume is being discussed), having an access point in the
way is generally a lousy idea.

Incidentally, I've had difficulties convincing customers (and one
skool) to run CAT5 wires. Wireless isn't always the best solution.
Recently, I've begun installing flat CAT5e cable. It doesn't solve
all the problems, creates a few new ones, but does allow for less
conspicuous CAT5 installations.
<http://www.vpi.us/cable-sf.html>
<http://www.vpi.us/cable-sf-cat6.html>
<http://www.vpi.us/installation/assemble-cat5e-sf.html>
Also available shielded.





--
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

Hi Jeff,

- Toshiba Portege M400 TabletPC running SP2 and latest updates
- Panasonic Projector Model # PanLB60NTU
- Wireless Access Points - Models may vary by classroom, I will have to
get this info on Tuesday (school closed until then)

What about adding a 2nd WiFi card to the tablets? Would that enable the
tablets to surf the web and transmit data to the projectors without any
conflicts?

Thanks for your time!

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

>Hi Jeff,

Bah-humbug. I'm having a difficult time due to assorted temporary
medical issues and feel like snarling at everyone within range. I'll
try not to be any more obnoxious and insulting than usual.

>- Toshiba Portege M400 TabletPC running SP2 and latest updates

Nice.
<http://www.toshibadirect.com/td/b2c/cmod.to?coid=-30603>
Which of the 3 models? I'm trying to determine if they have enough
horsepower to drive a PCMCIA video card. The good news is that the
built in display (1024x768) is exactly the same as the maximum size on
the PT-LB60NTU.

>- Panasonic Projector Model # PanLB60NTU

Try: PT-LB60NTU instead.

Oh crap. No wired networking. Wireless only.
<http://www.projectorcentral.com/Panasonic-PT-LB60NTU.htm>
Looks like you have no choice and some of my previous suggestions
aren't going to work. It's either wireless, or NTSC/SVideo.
I'll post some more after I bludgeon the new and improved Acrobat 8.x
into displaying the data sheet and manual.
<http://www.projectorcentral.com/pdf/projector_spec_3264.pdf>
<http://www.projectorcentral.com/pdf/projector_manual_3264.pdf>
I need to determine how the Panasonic connects to the wireless network
(peer to peer or infrastructure).

>- Wireless Access Points - Models may vary by classroom, I will have to
>get this info on Tuesday (school closed until then)

Try to find out if they are rate limited in any way, running at fixed
wireless speed, or have some from of existing QoS. It might slow
things down if present. Also, try to determine if the skool wireless
hops around to different channels depending on interference. That
will make finding a "clear" channel difficult.

>What about adding a 2nd WiFi card to the tablets? Would that enable the
>tablets to surf the web and transmit data to the projectors without any
>conflicts?

Yes, that will work and has two big advantages.
1. It can be placed on a "clear" channel and not interfere with
wireless web surfing.
2. It will not share/divide airtime between the two wireless
networks.

My guess(tm) is that what you're trying to do is give a live
demonstration of surfing the web to a class. Both the internet
connection and the wireless projector are via wireless. Is this
correct?

If so, then I have yet another suggestion. Run a CAT5 cable from the
skool internet network router and plug it into the Portage M400
ethernet port. Use wireless to the PT-LB60NTU and pray that nobody
else is spewing wireless junk around the classroom at the same time.
This is also not a commonly supported configuration. Toshiblah
supplies some kind of system tray application that switched between
ethernet and wireless. You need to have both running at the same
time. Some tweaking will be required.

The other way is to run a cable for the projector, using either the
VGA cable or NTSC/SVideo coax, and run the internet connection via
wireless. This has the advantage of not requiring anything weird on
the Tablet PC and not having the high speed wireless video interrupted
by someone watching YouTube in class instead of paying attention. The
local hospital has such an arrangement using some kind of VGA
amplifier near the podium. I'll guess that the total wire run is
about 50ft. Works nicely and is what I would recommend. Too bad it
doesn't use the wireless part.

Adding a 2nd wireless card will also work, but with some limitations.
Typical web browsing traffic is not sufficient fast to slow down the
wireless part of the puzzle very much. What will kill it is streaming
video. Displaying YouTube of Google Video with two wireless
connections or interference from other in class wi-fi devices is going
to be a problem. If you put the two wireless networks on different
channels (1, 6, or 11), then they can run simultaneously without
mutual interference. The projector and tablet PC will be setup using
ad-hoc, and NOT infrastructure to get speed and avoid self
interference. The skool wireless to the internet is on a different,
non-overlapping, channel. However, if you have no control over the
skool network, this may not be possible.

More when I read the manual.

Oh-oh. From the very fine print notes at the bottom of the data
sheet:
Content and DVDs set with DRM (Digital Rights Management) cannot
be transmitted.
Sorry, no movies in class. Unfortunately, that also includes
copyrighted training videos and material. You might want to check on
this.

--
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

Jeff Liebermann <(E-Mail Removed)> hath wroth:

>Oh crap. No wired networking. Wireless only.
><http://www.projectorcentral.com/Panasonic-PT-LB60NTU.htm>
>Looks like you have no choice and some of my previous suggestions
>aren't going to work. It's either wireless, or NTSC/SVideo.
>I'll post some more after I bludgeon the new and improved Acrobat 8.x
>into displaying the data sheet and manual.
><http://www.projectorcentral.com/pdf/projector_spec_3264.pdf>
><http://www.projectorcentral.com/pdf/projector_manual_3264.pdf>
>I need to determine how the Panasonic connects to the wireless network
>(peer to peer or infrastructure).

The wireless section is a piece of junk. Unless I missed something,
there exactly one page (Pg56) in the manual on wireless setup. It
doesn't offer anything other than the usual SSID and "password". I
can't tell if it supports WEP, WPA, WPA2, or any form of encryption or
authentication. I can't tell if it's a client, an access point, or a
bad joke. The fact that it has a name sorta implies that it might be
an access point instead of a client. All the illustrations show a
direct wireless connection between the laptops and the projector. I'll
make an astute guess(tm) that it's an access point, not a wireless
client. If so, you should be able to connect directly to it using a
2nd wireless card (or USB dongle).

There's something called "web control", but I suspect that's just the
same menu via wireless. The specs on Pg 65-66 are no help and only
mention that it supports 802.11b/g. Wooopie.

I hate to say this, but from here, it appears that this projector is
seriously deficient in the wireless section. I'll try to find some
reviews and possibly help from the Panasonic web pile, but it looks
rather dismal from here. Meanwhile, Pg 56 says to go look on the
supplied CD-ROM for wireless instructions. I can't find this CD-ROM
on the Panasonic web pile, so you're on your own. Hopefully, it
hasn't been tossed.
<http://catalog2.panasonic.com/webapp/wcs/stores/servlet/ModelDetail?storeId=11201&catalogId=13051&itemId=9 7337&surfModel=PT-LB60NTU>
Wait.... I found it. Go to the support tab and download the "Wireless
Functionality Guide". You get to install the Wireless Manager ME 3.0
on your Tablet PC. Oh for joy. Yet another driver. Argh.... It's
complicated. Gotta do some more reading (instead of guessing). Back
later.


--
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

Jeff Liebermann <(E-Mail Removed)> hath wroth:

><http://catalog2.panasonic.com/webapp/wcs/stores/servlet/ModelDetail?storeId=11201&catalogId=13051&itemId=9 7337&surfModel=PT-LB60NTU>
>Wait.... I found it. Go to the support tab and download the "Wireless
>Functionality Guide". You get to install the Wireless Manager ME 3.0
>on your Tablet PC. Oh for joy. Yet another driver. Argh.... It's
>complicated. Gotta do some more reading (instead of guessing). Back
>later.

Me again. It's not as bad as I first assumed. Apparently the
wireless setup is seperately documented from the projector setup.

The PT-LB60NTU will do either ad-hoc or infrastructure mode. The
factory default is ad-hoc.

It will do WEP, WPA-PSK (TKIP or AES) encryption. I can't tell for
sure, but it appears that ad-hoc mode only supports WEP encryption.

This is going to be somewhat of a challenge to setup as the Wireless
Manager ME 3.0 is rather feature infested. I could not find a "mode"
similar to what I think you'll be using in the classroom in the
"Wireless Functionality Guide" sample setups. At least you have the
option of trying both infrastrure and ad-hoc modes.

Good luck.

--
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

isn't this like connecting to an AP, while also connecting to other wireless
devices
within the same network... like printers, other sharing PC, network devices
?
I would think that if your local AP (for the network)
and the projector were all on the same SSID - then it would work ?