Note: Don't take these numbers too literally. They're intended solely to provide an estimated magnitude of the challenge
The issue is how much the signal power must be reduced to overcome this problem. The difference in free space loss between two antennae in the same AP (lets assume 6 inches) and a nearby client radio (let's assume 16 feet) is roughly 30 dB. So, if you want -65dBm at the client radio, you'll have about -35dBm at the other 5GHz antenna. Chuck Enfield Manager, Wireless Systems & Engineering Telecommunications & Networking Services The Pennsylvania State University 110H, USB2, UP, PA 16802 ph: 814.863.8715 fx: 814.865.3988 From: "Phillippe Hanset" <[email protected]> To: "EDUCAUSE Wireless Issues Constituent Group Listserv" <[email protected]> Sent: Thursday, June 30, 2016 9:01:12 AM Subject: Re: [WIRELESS-LAN] Turning off 2.4 on a select SSID? Quite interesting. Thank you. While listening to the explanation of attenuation related to the proximity of the two radios within a same AP I thought “Bad for sensors, but isn’t it what we actually want in high density deployment like an auditorium?”. So, maybe running two radios withing one AP at 5 GHz in an auditorium would reduce the signal and accomplish the small cells pattern that we want. Just thinking out loud here! Has someone tried this? Philippe Philippe Hanset www.anyroam.net www.eduroam.us GPG key id: 0xF2636F9C On Jun 30, 2016, at 8:23 AM, Kees Pronk < [email protected] > wrote: All, Little kick at the discussion from a while ago: There is a YouTube video now from 7signal in which dual 5GHz radio setup is discussed: https://youtu.be/6eueR3PYXlA (from 11:30 in the video). Pretty interesting! BR, Kees Van: Kees Pronk Verzonden: donderdag 7 april 2016 13:45 Aan: [email protected] Onderwerp: RE: [WIRELESS-LAN] Turning off 2.4 on a select SSID? Hi Chris, “you could in theory double the airtime available” I would be interested in your actual experience with this. Now that a few vendors have taken this approach and others stay away from this. Arguments in favor of 5/5 you will find these abundant on the vendors marketing pages, but how about : Extra COGS (band pass filters etc), extra complexity with your channels plans (need a lot of separation between the 5/5 radios), you must enable DFS channels on every AP but what about false positive radar detects? What about the 2 radio’s ‘deafening’ each other while trying so send/receive at the same time. Please keep us posted and maybe others testing with this 1. Innovation 2. Marketing gimmick (pick one ;-) Best regards, Kees Van: The EDUCAUSE Wireless Issues Constituent Group Listserv [ mailto:[email protected] ] Namens Larry Dougher Verzonden: donderdag 7 april 2016 03:11 Aan: [email protected] Onderwerp: Re: [WIRELESS-LAN] Turning off 2.4 on a select SSID? Thanks Chris! Larry Dougher Chief Information Officer Information Technology Services Windsor Southeast Supervisory Union 127 State Street, Windsor, VT 05089 Email | Google+ | Twitter | LinkedIn | 802.674.8336 On Wed, Apr 6, 2016 at 2:45 PM, Chris Adams (IT) < [email protected] > wrote: BQ_BEGIN Larry, We have deployed 802.11ac WAPs in many locations, but only have 80mhz channels enabled sparingly around campus. My hope is that by having the SDR option, we could configure 2x 5ghz radios with either 20Mhz or 40Mhz channels, logically operating as 2 WAPs. Our wireless use case is primarily for internet access – we just don’t have a need for true wave1/2 802.11ac throughputs at this time. To see true Wave2 throughputs, I believe the client WNIC would need to be upgraded. If we could operate 2 “logical” 5ghz WAPs from a single unit for a small increase in price, I think this is where our greatest benefit would be at this time as you could in theory double the airtime available. This is based on several assumptions I am making – I have not gotten my hands on the new AP250 yet but I am actively looking to do so. http://boundless.aerohive.com/blog/Designing-WLANS-What-If-we-could-double-our-airtime-at-5-GHz.html Thanks, Chris Adams Director, Network & Telecom Services Division of Information Technology University of North Georgia From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto: [email protected] ] On Behalf Of Larry Dougher Sent: Wednesday, April 6, 2016 2:28 PM To: [email protected] Subject: Re: [WIRELESS-LAN] Turning off 2.4 on a select SSID? Chris, I have a question about the AP250, but may be a question about MU-MIMO more generally. So, all things being equal, would a 5Ghz 802.11ac device/client see any benefit from a Wave 2 AP or would that device/client have to have an upgraded/new 802.11ac 5Ghz Wave 2 chip to see a benefit? Thanks, Larry Dougher Chief Information Officer Information Technology Services Windsor Southeast Supervisory Union 127 State Street, Windsor, VT 05089 Email | Google+ | Twitter | LinkedIn | 802.674.8336 On Wed, Apr 6, 2016 at 1:30 PM, Chris Adams (IT) < [email protected] > wrote: BQ_BEGIN I echo Jeremy’s sentiment – our experience with band-steering has been overwhelmingly positive. We are also not (currently) using DFS channels – but may be revisiting this soon. I’d estimate almost 2/3 of our 2.4ghz radios are disabled. I am very happy to see the new Aerohive AP250 has a SDR with the option of disabling the 2.4ghz radio in favor of having 2x 5ghz radios. Thanks, Chris Adams Director, Network & Telecom Services Division of Information Technology University of North Georgia From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto: [email protected] ] On Behalf Of Jeremy Gibbs Sent: Wednesday, April 6, 2016 1:27 PM To: [email protected] Subject: Re: [WIRELESS-LAN] Turning off 2.4 on a select SSID? I find the opposite to be true with band steering. If we turn it off, the majority of our clients won't connect to 5 Ghz, even if they are right above an AP. This causes lots of disconnect problems and congestion in the 2.4 Ghz spectrum. Turning band steering on fixes the problem for us. -- Jeremy L. Gibbs Sr. Network Engineer Utica College IITS On Wed, Apr 6, 2016 at 1:18 PM, Turner, Ryan H < [email protected] > wrote: BQ_BEGIN All, This is probably a fool’s errand, but we are debating experimenting with turning off the 2.4 spectrum on our eduroam SSID on parts of campus that have a dense 5 gig coverage. We’ve always positioned eduroam as the premium SSID, and left a WPA2-PSK SSID for all the rest that don’t support advanced EAP methods. We are debating trying this in just the IT building to start (see how many people scream). Has anyone done anything like this? The goals would be to continually remove traffic from the garbage bands, hopefully increasing client performance. Band steering isn’t very good. Thanks, Ryan Turner The University of North Carolina at Chapel Hill [email protected] ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/ . ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/ . ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/ . BQ_END ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/ . ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/ . BQ_END ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/ . Disclaimer ( http://www.avans.nl/over-avans/e-mail-disclaimer ) ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/ . BQ_END ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/ . ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
