Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I have a small home network that is currently running 802.11g. Two computers that are capable of 802.11n and two devices (a BlackBerry and a Skype phone) that are limited to 802.11g. I have a few neighbors running 802.11g but their signals are very weak.

  1. How big an impact will the two G devices have on N speeds? Will they pull the whole network back down to G? These two devices are hardly ever used where as the other N devices are heavily used.

  2. If I add an N router to the network (instead of replacing the G) and set my existing G router to use channel 1 with 20MHz bandwidth and then set the N router to use 6 & 11 for 40MHz will I eliminate the overlap and allow for full speed on both networks?

share|improve this question
add comment

2 Answers 2

up vote -1 down vote accepted
  1. G devices don't knock the whole network down to G speeds. They just take more time on the air than an N device would need for moving the same amount of data. Well, that and they keep N devices from using a few minor speed optimizations that N devices can use when there are no legacy devices around.

  2. Your 2.4GHz-only plan could work, but you'd be using up the entire 2.4GHz band just for 802.11, and you wouldn't be leaving any room for Bluetooth or any other users of 2.4GHz (Wii Remotes, many cordless phones and baby monitors, etc.).

    Hopefully your two N-capable computers are dual-band, so they can do N in 5GHz. If so, I recommend you get an N router that can do N in 5GHz, and leave your existing router serving G clients in 2.4GHz.

    (By the way, I think the channel numbers in your 2.4GHz HT40 plan would be "6 & 10" or "7 & 11". The extension channel is the control channel +/- 4, not 5.)

share|improve this answer
    
My two N capable devices are also both 5 ghz capable but I wonder about their ability to connect on that frequency. They will need to connect through 2-4 sheet rock walls. Stick construction. Your typical US built 2000 era home. I have no feel for success and would hate to spend the extra money on a dual band router. If I knew for sure, that would be my best option. –  andleer Jun 1 '10 at 18:38
    
Useful answer, but Bluetooth does not need "room" in the 2.4Ghz band, since it already uses pretty much the whole of that band anyway. Every BT connection hops to 79 different very narrow frequencies within the band 1600 times per second. Yes, 1600 Hz. The entire point of frequency hopping is to enable it to operate in "noisy" RF environments, especially since this is an unlicensed band. –  AdamV Jun 1 '10 at 20:28
    
@AdamV Bt's noise tolerance was not designed to overcome a challenge like HT40. An 802.11n HT40 file transfer is a solid wall of noise around 33mW high, across 2/3rds of the band. Your typical 2.5mW Bt radio simply can't bust through that. So 2/3rds of frequency hops it makes are blown away. It's worst on laptops, where WiFi and Bt are both popular, but where the internal WiFi and Bt antennas often have suboptimal separation. This is why the 802.11n spec includes the "40MHz intolerant" bit, which, sadly, is rarely implemented/honored. Bt and HT40 don't mix. –  Spiff Jun 1 '10 at 22:01
add comment

If you buy a router that supports G and N, you should have no issues. N devices will run at the faster speed. G devcies at their speed.

Not sure where you are but this D-Link has worked well in a mixed environment I'm sure there are others.

DIR-655

share|improve this answer
    
I read this and wonder about the ability of N and G devices to co-exist on the same channels. smallnetbuilder.com/wireless/wireless-features/… What the article doesn't answer is can I use ch1 for G and then 6 & 11 for N or as @Spiff pointed out 6 & 10 or 67 & 11 (but I think my original assumption of 6 & 11 is correct.) –  andleer Jun 1 '10 at 18:40
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.