32 channels are supported (includes the 4.9 safety bands for anyone allowed to use them)...no reuse of any channels...
So, 1,6,11, then all of the 5Gig (including the latest). Normally, the new extended channels (and safety) are used for bridging since full client support isn't up to par just yet. But that means there's 23 channels to pick from - lots of flexibility in noisy environments. Behaves a lot like a L2 wired switch. Jon 303-808-2666 Xirrus(tm) Array...the Air is the Network(tm)...visit us at www.xirrus.com -----Original Message----- From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:[EMAIL PROTECTED] On Behalf Of James Eyrich Sent: Friday, April 11, 2008 12:18 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] many clients, one room -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 What 14 channels are you using? Are you reusing as you go around the array or using a band? Jon Freeman wrote: | Some math offers insight on this question? | | | | Assuming the following: | | | | · we?re looking at a single area (i.e. lecture hall), | | · No retransmits are allowed (not real world, but is a best case | example) | | · we?re talking about an average sized PPT of 10MB (looking | through my PPT folder this was just my average) | | · Student and teacher expectations of speed is drawn from their | homes (i.e. cable and DSL), less than this will be noticed and likely | complained about | | · the room?s average data rate is 54Mbs (10 people by 10 people | = 50ftx50ft) | | · 100 people, all downloading at the same time | | · max radio density for Meru is 3 (i.e. 3 channels of coverage, | this is the most non-overlapping channels you can light in this area | without interference problems using their latest gear) | | · Actual throughput for TCP data is 20Mbs per channel (54Mbs | less Wi-Fi management overheads ? this is a number referred to in the | 802.11 spec and one I?ve observed many times) | | · Max radio density available from other shipping solutions | today is 15 channels | | | | _Meru Solution:_ | | | | · 20Mbs x 3 = 60Mbs converting to Bytes /8 = 7.5MB/sec /100 | people = .075MB/sec (using 1024KB to the MB, this is 76KB/sec/user of TCP!) | | · Time to download 10MB/.075MB = 133 sec/user to download a 10MB | file (_about 2 minutes_), so a 40MB file would take ~8min/user?. | | · Link throughput then is 76KBs TCP for each user?.you decide if | that?s acceptable | | | | _14 channel solution:_ | | | | · 20Mbs x 15 = 300Mbs | | · 5 times the bandwidth = 5 times the throughput | | · 76KBs/user x 5 = 380KBs TCP for each user of link throughput | (and this is a little bit better than most uplink speeds on home | broadband, www.speedtest.net <http://www.speedtest.net> is what I?ve | used on many LANs) | | · Instead of 2 minutes waiting, the 10MB file downloads with | this solution in _26 seconds_, and about 1 ½ min for a 40MB file, | versus 8 minutes. | | | | So, we can assume that Frank?s interviews from 2 years ago don?t account | for the latest technologies. Sorry Frank, I don?t mean to poke holes in | your study, but it is 2 years old and we are talking about technology. | | | | Didn?t we stop trying to manage limited bandwidth when ATM failed? When | did we go back to thinking that?s ok? | | | | I like more power, more speed, better, faster?. | | | | Jon | | 303-808-2666 | | *Xirrus**?** Array...the**/ Air/** **is the Network?...visit us at | www.xirrus.com*** | | | | *From:* The EDUCAUSE Wireless Issues Constituent Group Listserv | [mailto:[EMAIL PROTECTED] *On Behalf Of *Frank Bulk | *Sent:* Friday, April 11, 2008 10:07 AM | *To:* WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU | *Subject:* Re: [WIRELESS-LAN] many clients, one room | | | | Based on research and interviews I performed two years ago, it appeared | that for dense client usage in a confined space, Meru was the product | most often implemented. These organizations chose Meru because it | worked well or better than the competitor. | | | | Competitors argued that their product wasn?t set up correctly or | optimally. | | | | I?ll let others with production networks pipe in with their experiences. | | | | Frank | | | | *From:* The EDUCAUSE Wireless Issues Constituent Group Listserv | [mailto:[EMAIL PROTECTED] *On Behalf Of *Don Wright | *Sent:* Friday, April 11, 2008 9:59 AM | *To:* WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU | *Subject:* [WIRELESS-LAN] many clients, one room | | | | I know this has been talked about and debated on this list before, | but what are people doing today when faced with a request like the need | ?for 100 students simultaneously downloading a powerpoint presentation". | Recently there was discussion on MCA vs. SCA vendors and how each | handles this worst case scenario. Since we are an MCA (Aruba), I?d be | interested in hearing what others have done or are planning for large | classrooms and auditoriums. | | -- | Don Wright | Network Technologies Group | Brown University | | wire --- less, wi-fi ))) more | | ********** 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/. - -- James Eyrich Wireless and Wired Network Designer CITES - Network Design and Maintenance - Network Design Office University of Illinois [EMAIL PROTECTED] 217-265-6867 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (MingW32) iD8DBQFH/6tyg6vS3xxAH94RAmyeAJ0czk7BnCl+EAE3NUSGP7hsH05TVQCfQEgH ZRNui72V36+t9OewVs/wIc4= =g1Ue -----END PGP SIGNATURE----- ********** 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/.
