tag:blogger.com,1999:blog-8244742868095974321.post5695591617522886808..comments2022-10-15T01:51:26.698+08:00Comments on Phased Coexistence: Eliminating 802.11a clients from your WLANScott Stapletonhttp://www.blogger.com/profile/04384149433798542121noreply@blogger.comBlogger4125tag:blogger.com,1999:blog-8244742868095974321.post-70694828102008075642012-04-22T11:54:57.740+08:002012-04-22T11:54:57.740+08:00I have not stated that 802.11a has any effect on t...I have not stated that 802.11a has any effect on the 802.11b/g radio. I mentioned that disabling 802.11b is well understood but not so with 802.11a.<br /><br />The reason for disabling 802.11a is for the same reason you would typically disable any legacy protocol - performance. It is the same reason that if the 802.11n Greenfield protection mode was supported by Cisco you would see an increase in performance of 5 GHz 802.11n clients, as 802.11a clients would be eliminated, assuming the environment was appropriate for enabling Greenfield. <br /><br />The point of this post was to demonstrate a way to disable 802.11a, moving a/b/g clients to the 2.4 GHz band, freeing the 5 GHz band up for 5 GHz-capable 802.11n clients. As stated in my comment above, "Essentially, you are sacrificing 802.11a/b/g clients, forcing them to operate at 2.4 GHz where (depending on the design / environment) the performance may be worse for the benefit of your 5 GHz 802.11n clients."<br /><br />The arrogance of your last comment is galling. The irony of course is that you haven't properly read and comprehended what has been written. A casual read of this blog will show that there certainly is not a problem with a lack of understanding.Scott Stapletonhttps://www.blogger.com/profile/04384149433798542121noreply@blogger.comtag:blogger.com,1999:blog-8244742868095974321.post-77376740306092990312012-04-22T08:22:53.109+08:002012-04-22T08:22:53.109+08:00Not sure I understand anything you have done. The...Not sure I understand anything you have done. The B/G and A bands have different radios and run on different frequencies. The two have absolutely no relation to each other. In fact the B/G radio can't even see the A radio and vice verse. So disabling the A band has no effect on the B/G side except that now all of your clients are on one of the 3 non-overlapping B/G channels. The A band has many more non overlapping channels giving the entire A spectrum more throughput availability. I think you should google some basic 802.11 websites and start to relearn what you think you know.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8244742868095974321.post-14993177547551180972011-12-20T16:40:59.014+08:002011-12-20T16:40:59.014+08:00Cheers.
Performance! The performance advantages o...Cheers.<br /><br />Performance! The performance advantages of disabling 802.11a are not as great as that seen when you disable 802.11b at 2.4 GHz but in an environment where you are trying to obtain the maximum performance from the WLAN, this is another tweak that can help.<br /><br />The performance improvement comes by hopefully eliminating or at least reducing the number of frames sent at slower data rates. Whilst the lowest data rate of 802.11a and 5 GHz 802.11n is quite similar (6 Mbps for 802.11a and 6.5 Mbps for 802.11n) not many WLANs would have clients transmitting at these rates.<br /><br />If we look at the middle rates though, you are much more likely to have 802.11a clients transmitting at 24 Mbps whereas a middle rate with 802.11n is somewhere around 58 Mbps (20 MHz channel) or 120 Mbps (40 MHz channel). This assumes two MIMO streams, 400 ns guard interval, etc. By eliminating or reducing these 802.11a clients, you are reducing the number of frames sent at 24 Mbps (for example) and allowing more frames of a higher data rate to be transmitted, improving performance.<br /><br />Essentially, you are sacrificing 802.11a/b/g clients, forcing them to operate at 2.4 GHz where (depending on the design / environment) the performance may be worse for the benefit of your 5 GHz 802.11n clients.<br /><br />Not appropriate or worth-while in many designs but another option where performance is key.Scott Stapletonhttps://www.blogger.com/profile/04384149433798542121noreply@blogger.comtag:blogger.com,1999:blog-8244742868095974321.post-68053061522108028152011-12-14T18:42:26.343+08:002011-12-14T18:42:26.343+08:00Great blog !
Why would you disable 802.11a, what&...Great blog !<br /><br />Why would you disable 802.11a, what's the advantage ?Anonymousnoreply@blogger.com