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!!!!

Reply to
mick
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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.

Reply to
Johann Beretta

"mick" hath wroth:

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).

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?

See:

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.

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.

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.

Reply to
Jeff Liebermann

Jeff Liebermann wrote in news: snipped-for-privacy@4ax.com:

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.

Reply to
DanS

DanS hath wroth:

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.

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.

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.

Also available shielded.

Reply to
Jeff Liebermann

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!

Reply to
mick

"mick" hath wroth:

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.

Nice.

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.

Try: PT-LB60NTU instead.

Oh crap. No wired networking. Wireless only.

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.

I need to determine how the Panasonic connects to the wireless network (peer to peer or infrastructure).

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.

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.

Reply to
Jeff Liebermann

Jeff Liebermann hath wroth:

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.

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.

Reply to
Jeff Liebermann

Jeff Liebermann hath wroth:

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.

Reply to
Jeff Liebermann

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 ?

Reply to
P.Schuman

Hi Jeff,

Thanks again for all the time it must have taken you to reply!!!! Sorry to hear about your medical issues -- hope you are doing well.

Current tablets:

Intel Core Duo T2300 1.66GHZ

80 GB HDD (7200RM Serial ATA) 1024 MB PC5300 DDR2 667MHZ

"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?"

Exactly.

"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."

This is one option -- however, some faculty would like to be able to walk around the room wirelessly and lecture from different points in the room.

"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."

Sorry - I'm not following what you meant by "What do you mean by running a cable for the projector using VGA cable or NTSC/SVideo coax?" How would you use these cables?

"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."

What do you mean by other "in class wi-fi devices? I think the idea will be that no one else in the class with have access (passwords) to access the network and slow it down.

"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."

How is this possible? What specifically prevents the video from being transmitted? Part of the multimedia carts that we purchased also includes a stand alone DVD player. So we could just play the video from the player, which is wired into the projector.

Thanks!!!

Reply to
mick

"mick" hath wroth:

Except for what's left of a cold or flu, I'm now fine. My brain is a bit mushy but still functional.

Ok, it's got sufficient horsepower to run a PCMCIA video card. However, I don't think it will be needed (or is even a good idea).

No problem. How much does the Toshiblah TabletPC weigh? Digging... Data sheet stays starting weight is 4.5lbs. Ok, take a common red brick that weighs about 5lb and ask the perpretrator of this requirement to hold it in a simulated TabletPC position for as long as they normally lecture. I'll give them 5 minutes before they give up and have to put it down. Dumb idea.

Get them one of the numerous wireless presentation pointer mouse devices. I give ocassional lectures and it's what I use. I don't like it but it makes more sense that doing curls with a heavy laptop.

It's the simplest system of all. The projector comes with a VGA (15 pin DE9S connector) cable. This goes to the external VGA connector found on the laptop. Oh-oh... maybe it doesn't have one. Digging... Whew.... It has a "RGB Monitor Port" which is the same thing:

Plug one end into the corresponding connector on both ends. Use wireless to connect to the existing skool wireless system, and you're done.

The problem is that the cable may not be long enough. The Panasonic data sheet doesn't seem to mention the cable length. It's usually fairly short at about 3 meters. Any longer and the image gets smeared on the screen. There are VGA extension cables up to about 100ft available. Belkin has one that's 100ft long. However, if the extension cable smears the image, you'll need some kind of "vga video extender" or whatever. Something like this:

Due to the high prices, you might want to try the extension cables first. With a maximum resolution of 1024x768, my guess(tm) is that

25ft total will be the limit.

It means my grammar needs help. Substitute "in the classroom". The problem is that if there are other wireless users in the classroom, they will interfere with the connection(s). It will have a much bigger effect on the wireless video as it uses more airtime and interruptions are more obvious. You might think that one could ask everyone to disable their wireless devices, but with the dramatic increase in devices that have Wi-Fi imbedded (MP3 players, cell phones, PDA's, etc), I think this would be impractical.

That will be a good idea. However, interference from other 2.4Ghz wireless devices will be a problem. The problem is that wireless video needs to have almost a totally RF free environment to function. The traffic is high bandwidth and interruptions are easily visible. This is not the case with casual internet browsing, where interruptions are typical, and bandwidth use is much less.

I'm not sure how the rights management works on the Panasonic projector. I found next to nothing on the topic in the manual but may have missed something. Apparently, the attorneys are worried that someone might setup a neighborhood theater and broadcast copyrighted content to the neighborhood. There's nothing in the projector that prevents this, but the projector seems to require the Wireless Manager Mobile Edition 3.0 software installed on the TabletPC. The DRM copy protection is in this software. I suggest you call Panasonic and ask the same questions.

Yep. That's the way to do it. Anything the DVD player will play can be projected. Same with the DVD player in the TabletPC when connected via a VGA cable. However, it's whether the Wireless Manager Mobile Edition 3.0 software will allow doing the same via wireless that I'm questioning. There's an excellent chance that the wireless video feature might be next to useless.

Read the docs for the Wireless Functionality Guide, under Support and Accessories at:

Reply to
Jeff Liebermann

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