Does the Airport Express/Extreme slow down when using 802.11N with G?

Libertine Lush

macrumors 6502a
Original poster
Nov 23, 2009
679
2
Hi everyone,

I'll likely be switching to Apple this Black Friday and intend to also get a new WIFI router with 802.11N to go along with the new iMac. However, in my research I read that if you're using a 802.11N WIFI router with 802.11N and 802.11G computers that mixing the two can slow down the whole network.

1) Is that true?

2) And, is that the case with the Airport Express and Extreme?

(I searched the forum before posting this question and in a thread unrelated to this specific question, there was a poster who said that because the Extreme has simultaneous dual band, it can dedicate one band to N and one to G. I know little about this stuff but I thought dual band merely means the 2.4GHz and 5Ghz signals--and not about transmitting 802.11N and G simultaneously.)

Thank you for any help.
 

ntrigue

macrumors 68040
Jul 30, 2007
3,805
2
The answer was in front of you. The Extreme runs G on 2.4GHz spectrum and N on 5GHz spectrum therefore having no conflicts. The Airport Express can run either G or N protocol.
 

Libertine Lush

macrumors 6502a
Original poster
Nov 23, 2009
679
2
Oh ok! I didn't know that G means 2.4GHz and N means 5GHz. When looking at all the N routers marketing their 2.4 & 5GHz signals, I naturally assumed both are N signals.

So then, am I correct in thinking that running the Extreme in a home where there are N and G-equipped WIFI computers would result in no slow down to the network at all, but running the Express in that same environment would? If that is what happens with the Express, will only the computer with the N signal be slowed down or the G as well?

Also, since you say that N means 5GHz, if I choose to use the N spectrum on the Express for the the new iMac does that mean the older G computers in the home won't be able to connect? Would I have to run the Express at 2.4GHZ, the G spectrum, so the older computers can connect but hobbling the capabilities of the N-equipped iMac?

Thank you!
 

alphaod

macrumors Core
Feb 9, 2008
22,173
1,216
NYC
Yes it will slow down.

N does not imply 5GHz; the N-revision has both the 2.4GHz and 5GHz frequencies.

If you use an B/G device on your N-router on the 2.4GHz frequency the speed will drop to 11Mbps/54Mbps respectively. Of course it will still perform better than most B/G access points. If you use an A device on your N-router on the 5GHz frequency, again it will drop to 54Mbps.

You can if you choose to choose N-only on both frequencies, but that will lock out almost all mobile devices (well the non-notebook computer devices nonetheless)

The best way to configure this [if you have the latest Airport Extreme] is to set the 5GHz to N-only (because almost nobody uses A and I doubt you do) and use it for your computers. Leave the 2.4GHz to mixed mode for the rest of your devices. For the Airport Express, you can't use both at the same time.

There are wireless access points that can broadcast a 2.4GHz N-signal in mixed mode and have B/G devices not decrease the throughput for N-devices. Those access points are very expensive are usually designed for large scare deployments and folks with deep pockets.
 

ntrigue

macrumors 68040
Jul 30, 2007
3,805
2
What the hell are you talking about? If he buys an Airport Extreme this week it will be dual-band. There will be no slowdown because his iPhone will use 2.4G and his iMac 5N. Of course you can complicate things by only using 2.4 or G or N but your answer was appropriate in 2006 not Q4 2009.
 

Libertine Lush

macrumors 6502a
Original poster
Nov 23, 2009
679
2
N does not imply 5GHz; the N-revision has both the 2.4GHz and 5GHz frequencies.

If you use an B/G device on your N-router on the 2.4GHz frequency the speed will drop to 11Mbps/54Mbps respectively. Of course it will still perform better than most B/G access points. If you use an A device on your N-router on the 5GHz frequency, again it will drop to 54Mbps.
Thank you! I have a much better understanding now. Could you explain why, however, B/G devices would still perform better on the 2.4GHz frequency on a N router then on B/G ones?

You can if you choose to choose N-only on both frequencies,...
Would dedicating N to both frequencies extend the range and speed of the N spectrum versus running it only on the 5GHz frequency? Would it effectively double it?

The best way to configure this [if you have the latest Airport Extreme] is to set the 5GHz to N-only (because almost nobody uses A and I doubt you do) and use it for your computers. Leave the 2.4GHz to mixed mode for the rest of your devices.
I intend to get the new iMac which has N WIFI; and I have 2 Windows laptops with G WIFI. So from my understanding of what you've told me, I should set the Extreme's (or maybe a Linksys--it's $60 less) 5GHz for the N spectrum from the iMac and the 2.4GHz for the G spectrum for both my Windows laptops. Is that correct?

Thanks a lot!
 

rusty2192

macrumors 6502a
Oct 15, 2008
997
81
Kentucky
Same network with simultaneous dual band?

I am also considering getting the airport extreme. I just have one question. If I set up one radio for N only 5gHz, and set the other to 2.4gHz mixed band, would they be on the same network? I want the N for my macs, but I need g for my iPhone and a wifi printer, so they need to all be on the same network.
 

angemon89

macrumors 68000
Feb 5, 2008
1,819
89
Bay Area, CA
You guys are kinda overthinking this. Just get the Dual Band Airport Extreme and set the Radio Mode/Channel to Automatic.

My Macs stay on N (if they are in close enough range due to the 5GHz), and everything else stays on G obviously. There is no need for a complicated setup. I promise you you wont see a difference.
 

Libertine Lush

macrumors 6502a
Original poster
Nov 23, 2009
679
2
Just get the Dual Band Airport Extreme and set the Radio Mode/Channel to Automatic.
What does automatic mode do? And does that affect the performance versus manually setting one frequency for N and the other for G?

My Macs stay on N (if they are in close enough range due to the 5GHz), and everything else stays on G obviously. I promise you you wont see a difference.
I have very little understanding of how wireless networking works so I dunno if this makes sense: Are you saying that 5GHz has a shorter WIFI range than 2.4GHz? So the network will run on N when it's close enough and G when it's farther away?

And when you say that you won't see a difference, is that to say that technically there is a difference when using Automatic mode?

Thank you.
 

BanjoBanker

macrumors 6502
Aug 10, 2006
354
0
Mt Brook, AL
With the AirPort Extreme in automatic, your iMac will be getting N strength signals and any G device that wanders in will receive G strength signals. Neither device will know the other is there as far as speed goes. Oh, the Express is for traveling, they do not like being turned on all the time. My old AirPort broke when my nephew and son were tossing a ball in the house and it took a hit. I pressed my trusty Express into duty as a stop gap that seems to have lasted about six months, or untill the Express crapped out. You will be very well served with the AirPort Extreme but you might also want to check out the Time Capsule. You get the same capabilities as the AirPort Extreme plus a 1 TB hard drive to use Time Machine to do your automatic backups. ::cool:
 

Libertine Lush

macrumors 6502a
Original poster
Nov 23, 2009
679
2
With the AirPort Extreme in automatic, your iMac will be getting N strength signals and any G device that wanders in will receive G strength signals. Neither device will know the other is there as far as speed goes. You will be very well served with the AirPort Extreme but you might also want to check out the Time Capsule.
Thank you for that, BanjoBanker.

After reading the replies on this thread and doing a bit more reading online I've decide I won't be getting the Express. It'll be either the Extreme or a Linksys with simultaneous dual band, as not only is it $60 less but I read in a review that the Extreme only has NAT firewall, not SPI, which the review said is of some significant disadvantage.
 

flynz4

macrumors 68040
Aug 9, 2009
3,131
37
Portland, OR
I have Verizon FIOS, and it would be a pain for me to move away from their provided router because it has a built in MoCA (it drives internet on the cable TV coax). The wireless on that router is only B/G.

I have a Time Capsule which is dual band... but I swear when I was running N and G simultaneously, I noticed a slowdown.

I have since decided to run all G through the wireless on the FIOS provided router. I have set up my TC on my internal network... and I run only my N computers on that wireless network. Things seem to fly.

Any desktop computer in the house, along with our home server, is hard wired using 1G ethernet.

/Jim
 

Libertine Lush

macrumors 6502a
Original poster
Nov 23, 2009
679
2
I have a Time Capsule which is dual band... but I swear when I was running N and G simultaneously, I noticed a slowdown.
Even if these slowdowns occur when running dual band (which i deduce from the past posts is Automatic mode?), am I right to say that for someone like myself who primarily uses the internet with my WIFI network and does no transfers from one pc to another in that WIFI network, theses slowdowns should not affect me because my ISP speed wouldn't even be able to reach the hobbled speeds of a router, let alone it's top speeds anyways?

So for instance, I just tested my ISP speed at SpeedTest.net and it said mine is about 15Mbps. I'm now using a G WIFI router, so the max speed is 54Mbps. So even with this older WIFI technology I won't be using the full potential of the gear as long as I'm just surfing the net. Is my reasoning correct?

Thanks.
 

flynz4

macrumors 68040
Aug 9, 2009
3,131
37
Portland, OR
Even if these slowdowns occur when running dual band (which i deduce from the past posts is Automatic mode?), am I right to say that for someone like myself who primarily uses the internet with my WIFI network and does no transfers from one pc to another in that WIFI network, theses slowdowns should not affect me because my ISP speed wouldn't even be able to reach the hobbled speeds of a router, let alone it's top speeds anyways?

So for instance, I just tested my ISP speed at SpeedTest.net and it said mine is about 15Mbps. I'm now using a G WIFI router, so the max speed is 54Mbps. So even with this older WIFI technology I won't be using the full potential of the gear as long as I'm just surfing the net. Is my reasoning correct?

Thanks.
In theory this is correct, but you may find yourself using bandwith within your network... which will benefit from the faster speed. I strongly recommend that you run TimeMachine to backup your new Mac. You can use any hard drive to do so... but one that is on your network could be used to backup several Mac if that is in your future.

We have Mac laptops now... and they can all back up to our Time Capsule (essentially a Airport and 2TB drive in one box). Since we almost never plug our laptops into the network... it is very convenient to have them back up wirelessly to the TC.

/Jim
 

Libertine Lush

macrumors 6502a
Original poster
Nov 23, 2009
679
2
In theory this is correct, but you may find yourself using bandwith within your network... which will benefit from the faster speed.
Could you explain what it means to be "using bandwith within your network"? Does that mean 2 or more computers using the connection at the same time?

I strongly recommend that you run TimeMachine to backup your new Mac.
Right now I have a 1TB Western Digital USB external. So I'll be using that with TimeMachine (which I'll learn about soon enough), since the Time Capsule's too pricey for me at the moment, on top of the iMac.

Thanks Jim.
 

flynz4

macrumors 68040
Aug 9, 2009
3,131
37
Portland, OR
Could you explain what it means to be "using bandwith within your network"? Does that mean 2 or more computers using the connection at the same time?
Examples of Bandwidth within the network are:

1) Transferring data between two or more computers
2) Transferring data between a computer and a network attached drive

Since you will be backing up to a USB drive... then I stand corrected. You will probably not be using bandwith within your own network. Your bandwidth will be limited by the connection to your ISP. For some reason, I thought that you would be having more than one computer on your network... and would be sharing data between them.

/Jim
 

dansuz1

macrumors member
May 7, 2003
83
0
Washington, D.C.
I have Verizon FIOS with a 802.11g router (which apparently I must use). I want to expand the range of the network plus provide ethernet connections to two rooms that are not wired for ethernet. I was thinking of buying two airport expresses to put in each of the two rooms. Since they're 802.11n and my Verizon router is 802.11g, will I only be able to get 802.11g speeds to the Airport Express routers? One of the issues I'm having is that when streaming Netflix and Vudu through our wireless Blu-ray DVD player, we constantly have speed issues.

How do I get the speed I need?

Thanks,

Dan
 

alent1234

macrumors 603
Jun 19, 2009
5,661
136
N is a much better protocol than G. On G i've read that something close to half the bandwidth was protocol overhead
 

balticgreen

macrumors member
Sep 8, 2004
56
18
Maryland
I have Verizon FIOS with a 802.11g router (which apparently I must use).
You need to have the FIOS router somewhere on your network but you don't have to use it for wireless. I have FIOS too and my router is located in my wire closet with the wireless turned completely off. All it does is connect the FIOS service into my central switch. Then in my office I have an Airport Extreme that serves all my wireless connections.

Since they're 802.11n and my Verizon router is 802.11g, will I only be able to get 802.11g speeds to the Airport Express routers?
Yes, if they're connecting to the Verizon router, the Airport Express routers will only connect at G speeds. If you buy an N router and use that for wireless instead of the Verizon router (like I'm doing) then the Express routers will connect at N speeds.
 

dansuz1

macrumors member
May 7, 2003
83
0
Washington, D.C.
balticgreen,

So I'm sure I understand, the FIOS router plugs into the outside FIOS line, and then is connected to your switch box.

Makes sense. Unfortunately my basement isn't wired for ethernet, so I'll have to buy 3 wireless hubs to get FIOS into the areas I need it.

But at least I have a way forward.

Thanks for the advice,

Dan
 

skye12

macrumors 65816
Nov 11, 2006
1,211
2
Austin, Tx
I want to buy the new AEBS, but my old g flying saucer by Apple still works great after 5 years. I do have n capable computers, but am not sure I'll
really see a performance difference. Typically 2 n MB's, an iTouch and a PS3
are connected to the network.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.