What power are the 2.4 and 5 GHz radios set to on the AP in the room?
If the clients see a higher power signal from 5 GHz they might be more likely
to connect to the 5 GHz radio.
With the extra channels you can set the power for the 5 GHz to 1 and still
not worry about interfering with a nearby AP.
On our Cisco controller we set the TPC power threshold for GHz to -50. This
resulted in 5 GHz radios being set to power 1 on most APs (except some
classrooms with multiple APs close together).
Of course it doesn't help the AP hear the client any better but the client is
likely making the choice of band on how well it hears the AP.
On some AP models the 2.4 GHz radio sends out a 3 dBm higher power signal
than the 5 GHz radio even before the 5 GHz signal losses more power than 2.4
GHz in going through most walls. At least as reported by the controller
show ap config 802.11a AP-name-here
show ap config 802.11b AP-name-here
But the data sheets show that some model APs can send out 1 dBm higher signal.
And of course the new FCC rules mentioned on the list recently makes
comparisons a bit more complicated also.
http://www.cisco.com/en/US/products/ps11983/products_qanda_item09186a0080bbfd1c.shtml
On Sep 20, 2013, at 11:21 AM, Danny Eaton <dannyea...@rice.edu> wrote:
> Jeff – we’re seeing the clients join at 2.4 Ghz, and just stay there. The AP
> for this one particular is in the room – about 10 – 15 feet away, so I don’t
> see any reason why it won’t go to 5. Other clients (Windows, Android) are
> associating at 5 Ghz. on that AP, and the specific Mac goes to 5 in other
> locations. It’s just a recurring problem across our entire wireless network.
> We’ve discovered that 45% of our wireless clients are Apple, and want to
> give them the best experience possible, which would happen in the 5 Ghz band.
> We’ve disabled band select in only one of the 14 controllers, due to
> problems with a professor’s Linux MINT distribution. Windows makes it very
> easy for a dual-band wireless card to prefer 5 Ghz over 2.4 Ghz, and, to
> borrow a phrase, “it just works”. Why can’t Apple?
>
> I am testing WiSM-2’s with 7.5.110.0 code right now, (currently the
> 3502/1142/1252 APs are using WiSM-1 with 7.0.240.0 code), so I’m hoping this
> is something that is “resolved magically” in the new wireless code, but it
> really seems to be something Apple CAN fix, if they wanted to.
>
> From: The EDUCAUSE Wireless Issues Constituent Group Listserv
> [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jeffrey Sessler
> Sent: Friday, September 20, 2013 10:59 AM
> To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
> Subject: Re: [WIRELESS-LAN] Dual Band Mac laptops...
>
> The Mac's will often start off on 2.4 GHz, and if they are stationary for a
> bit, will migrate to 5 GHz. This is what I've observed in our Cisco
> environment without the use of band select. Of course, the Mac makes the
> choice between 2.4 and 5 based on several factors including performance, so
> depending on how dense (or not dense) your deployment is, the Mac may prefer
> 2.4 if the clients are father than 20-30 feet from an AP.
>
> This is really easy to see in Prime - If you have residential Mac user (or a
> office user who is stationary for hours), go look at this client record.
> You'll likely see the Mac associate at 2.4, then re-associate at 5 a bit
> later. I've also noticed that once a Mac moves to 5 on a given AP, it will
> try to re-associate at 5 assuming it's back in same location.
>
> I'd avoid band select - after all these years, the wifi client drivers are
> still problematic, and trying to use magic on the AP side to steer the client
> always results in some sub-set of unhappy clients (especially in EDU).
>
> Jeff
>
> >>> On Friday, September 20, 2013 at 7:43 AM, in message
> >>> <003901ceb60f$b443ccf0$1ccb66d0$@rice.edu>, Danny Eaton
> >>> <dannyea...@rice.edu> wrote:
> So, what we are seeing in our wireless is that dual-band Mac’s seem to prefer
> the 2.4 Ghz side of things. I’ve searched, and had some of the Mac
> specialists on campus search for a way to encourage them to connect to 5 Ghz.
> I know there’s a way in the Windows OS to do such a thing in the driver
> settings. Does anyone know of a way to make this happen on a Mac?
>
> Respectfully,
>
> Danny Eaton
>
> Snr. Network Architect
> Networking, Telecommunications, & Operations
> Rice University, IT
> Mudd Bldg, RM #205
> Jones College Associate
> Office - 713-348-5233
> Cellular - 832-247-7496
> dannyea...@rice.edu
>
> Soli Deo Gloria
> Matt 18:4-6
>
> G.K. Chesterton, “Christianity has not been tried and found wanting. It’s
> been found hard and left untried.”
>
>
>
>
> ********** Participation and subscription information for this EDUCAUSE
> Constituent Group discussion list can be found
> athttp://www.educause.edu/groups/.
> !DSPAM:911,523c70b659021360117255!
> ********** Participation and subscription information for this EDUCAUSE
> Constituent Group discussion list can be found
> athttp://www.educause.edu/groups/.
> ********** Participation and subscription information for this EDUCAUSE
> Constituent Group discussion list can be found
> athttp://www.educause.edu/groups/.
---
Bruce Curtis bruce.cur...@ndsu.edu
Certified NetAnalyst II 701-231-8527
North Dakota State University
**********
Participation and subscription information for this EDUCAUSE Constituent Group
discussion list can be found at http://www.educause.edu/groups/.
