Correct. As I mentioned, 802.11n is all about speed. If you don't need more speed than 802.11g can provide, then a compatible 802.11n card will suffice. I also couldn't find one for 5.6GHz that does Pre-802.11n Draft 2. However, if you don't need the speed, or need range instead, just get an 802.11a PCI card.
I'm not sure where they obtained those numbers but there's a bit of misinformation buried in them.
There are two type of technology specified in Pre-802.11n Draft 2.
One is beam forming, where a smart antenna attempts to put the antenna gain in the direction of the wireless client, while simultaneously putting nulls in the direction of interference. The antenna gain of such systems is considerably more than the commodity 2dBi coaxial antenna, and you might get 70 to 250 meters if everything were perfect. However, the beam forming technology does not offer much in the way of speed improvement over 802.11a/g at 25Mbits/sec max thruput. Some models will do Super-G, Turbot-G, Afterburner, and whatever to get to perhaps 50Mbits/sec, but such non standard technologies are NOT part of 802.11n. Otherwise, the beam forming flavor of 802.11n will work with literally any commodity 802.11a/g client and does not require anything special in the client.
The other method is spacial multiplexing. This is where the access point and the client have multiple radios, which transmit individual data streams on each radio, simultaneously, and possibly on the same frequencies. In theory, if each data stream takes a different path, the data will not arrive simulaneously at the receiving end, thus magically preventing interference between data streams. (I'm not sure I completely understand how it works so treat my explanation with suspicion). Under idea conditions, 3 radios will give you 3 times the thruput. The problem is that it doesn't magically give you any improvement in range over a single radio. Just more bandwidth.
The spacial mux crowed couldn't seem to achieve 3 times the thruput, so they cheated. Instead of the xmit spectra occupying the usual
20Mhz, they increased it to 40MHz bandwidth. The also crammed in 54 OFDM carriers, in place of 802.11a/g 48 carriers. This gave them more than double the thruput per channel, which makes the spacial mux suitable for video. In theory, it can go 600Mbits/sec:
However, you can get those impressive speeds only at short range. Pre-802.11n Draft 2 spacial mux technology really doesn't like interference, frequency selective fading, leagacy wi-fi, and long path delays. The exception is multipath, with 802.11n spacial mux
*REQUIRES* to operate. Just about anything else in the 2.4Ghz band will degrade the thruput. The junk increases the bit error rate which causes the wireless router to slow down. If configured for 802.11a/g compatibility, it will switch to 802.11a/g mode, essentially disabling all the wonderful MIMO features for which you paid good money.
About the only situation where 802.11n spacial multiplexing makes sense, is an enclosed area (i.e. a room), with both the wireless router and client in the same area, and streaming HDTV video through the link.
Do you intend to use both of the 600N radios at once ?
I think that we are all trying to understand the importance of N to you if you don't want to use 2.4 Ghz band ?
And if you intend to use A, then there are countless adapters.
Unless, that is, you do intend to run both radios at once?
I have a client that fixes on optimization of a certain concept (in this case, using all possible wifi bands), often without knowing why or if he will really want/need to do all the things he insists he must be able to do.
No offense intended, just a reality check. Once you achieve the holy grail, will you really use both bands? I believe that you will need two cards to do both bands simultaneously in any case.
No I just need one fast reliable channel, two would be nice but like I said the 2.4GHz channel is just to crowded.
Ya.. Gimme Gimme. :)
No like I said, I wasn't aware that 802.11a was 5Ghz, but it isn't as fast as n... but that's a whole other discussion. I can't use 2.4Ghz because its just become to cluttered. Linksys makes a dual band USB key, but I can't use it because it will just end up being stolen. Linksys will produce a card, but when I don't know. Till then I'm stuck with 802.11a...
My typos, or the Wikipedia article mistakes? I noticed (after posting) that there are few numbers that are wrong. The author(s) mixed up over the air rates and connection data rates. The following are connection data rates:
If they mean maximum THRUPUT rates, it should be:
It's also different between TCP and UDP traffic. See:
As for the ranges shown, the tables are backwards. The longest range should be at the slowest speeds.