[chasg]

Hi All,

If I set up my PowerBook (a 12" G4, equipped with Airport Extreme) so that it hosts a wireless network (which is termed "ad-hoc" mode, a wireless network with a router is termed "infrastructure" mode), will the resulting network run at "b" or "g" speeds?

The reason I'm asking is that my camera, a Nikon DSLR with wireless unit, will connect to my Powerbook a "b" speeds if the Powerbook is hosting the netork, but it will connect to a wireless router at "g" speeds. Note: this isn't my testing that has shown this, it's well documented (by Nikon, among others), it's an issue with ad-hoc vs. Infrastructure networks.

I've got a thread running in the Network forum asking about travel-sized wifi routers (so that I can easily transport said router to, say, a wedding, and transmit to my PowerBook as I shoot, at "g" speeds). One respondent to my thread has suggested that this issue with ad-hoc vs. infrastructure is related to the camera, and is not a universal issue. I can't dispute him, as I've never tested this (computer to computer network speeds with two computers, rather than camera to computer).

So, can anyone _definitively_ state that an ad-hoc network runs at "g" speeds when connecting two computers together, or is a router necessary to get those speeds?

Also: if an ad-hoc network _can_ run at "g" speeds, why is my camera's wireless transmitter so limited?

Thanks in advance for any help,

Chas

[hookem2oo7]

I've never been able to get more than 802.11b speeds out of any ad-hoc connection i've set up between two computers (whether it was windows to windows, mac to windows, etc, etc)

[chasg]

Thanks very much for that info, it's helpful.

Chas

[Simon]

Originally Posted by hookem2oo7

I've never been able to get more than 802.11b speeds out of any ad-hoc connection i've set up between two computers (whether it was windows to windows, mac to windows, etc, etc)

Unfortunately, I'll have to second that. I never saw more than 700 kBytes/s which corresponds to b speeds rather than g.

[ghporter]

Networking issues go in the NETWORKING FORUM. Even if you're talking about network connections for your camera...

[chasg]

Sorry about that, I posted here specifically 'cause I'm using a 12" PowerBook.

Luckily, my question has been answered (to be honest, I don't think I would have gotten the same answer in far less populated Networking Forum).

Thanks everyone,

Chas

[ghporter]

Less posted in, maybe, but NOT less visited.

It's good that Simon and hookem happened to be in the PB forum to answer your question-not everyone there knows more about networking than "AirPort works great!"

I'm not certain why it's this way, but I've never heard of an ad hoc network getting decent speeds. It may have to do with the protocol itself, but I have never found enough technical data on ad hoc to be able to say for certain.

On the other hand, wireless routers are inexpensive and simple to set up, so you could save yourself aggravation by buying one (any device that says "WiFi" compatible will work with AirPort).

[Simon]

Originally Posted by ghporter

On the other hand, wireless routers are inexpensive and simple to set up, so you could save yourself aggravation by buying one (any device that says "WiFi" compatible will work with AirPort).

That is definitely true.

Though be warned about g speeds. With my AP base station set up three feet away from my MBP, I have never seen wireless speeds in excess of 1.7 MBytes/s (I've tried this in different locations to rule out interference issues) which is certainly better than the 700 kBytes/s I see with b, but it is nowhere near the roughly 5 MBytes/s you'd expect from the g specs. Obviously the 55 MBps is a best effort peak speed and doesn't translate to real world use.

It's fine for your home network as long as you don't move large files, but it's certainly nothing for the professional environment or when you want to transfer GBs of data.

[ghporter]

G wireless is rated as having a maximum throughput of 54 megaBITS per second, or 6.75 megaBYTES per second. But that includes overhead for everything from security management to error correction and standard ethernet management. USABLE throughput is going to be lower-often much lower.

If you're anywhere other than directly in front of the base's antennas, factor in the standard's traffic management and error handling protocols, which often can cut the speed in half (~3.375MBps), even very near the base. And if there's anything at all around that could interfere or block your signal (furniture, people, nearby 2.4GHz cordless phones) you can count on another 50% reduction in many cases (~1.6875MBps). 1.75megaBYTES per second ain't that shabby for wireless. ESPECIALLY when B standard equipment has exactly the same factors to deal with-and getting more than 25% of the rated max (around 340 kiloBYTES per second) as actual usable throughput is not easy.

[chabig]

I'll test the connection speed with my son's MacBook this weekend and report back.

Chris

[chasg]

So Chris, any results?

How would you test throughput in this case, anyways? (no sarcasm, I'd really like to know).

Chas

[chabig]

Chas,

I forgot to try it. My plan was to connect the two in ad-hoc mode and simply time a large file transfer. Although the resulting transfer rate might not be terribly reliable, it should be fairly obvious whether the number is faster or slower than 802.11b speeds.

Chris

[chabig]

Come to think of it, this could probably be done at an Apple store.

Chris

[chasg]

LOL, and here I thought you had some great, esoteric, throughput evaluation program ;-)

Well, if you ever do manage to try this out, let us know! (btw: why an Apple store?)

Chas

[chabig]

It would be easy to go to an Apple store, set up a computer to computer network on one machine, then connect from another.

Chris