RE: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n?
David, Thank you. Soso far: upgrading the AP infrastructure to 11n; the WLAN is open to anyone to connect; but no problems to date with 11n in the 2.4 GHz band for these clients (channel assignments/access; or IP address allocation). No authentication at all? I'm guessing the WLAN is firewalled from the admin/backend systems, and that students/whomevers would be accessing Web-based resources? Any analysis or impressions of the kind of traffic these 17K iOS devices are generating -- how much is video, data, etc? Regards, John Cox Senior Editor Network World From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of David R. Morton Sent: Wednesday, August 25, 2010 11:43 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? John, We are just beginning our 802.11n migration, but to date we haven't seen anything that is causing concern. On the IP address side, our wifi network is open to any device to connect and access on-campus resources; so we do need to make sure that there are enough addresses available for them to connect. Based on our logs, we see approximately 71k unique devices (MAC addresses that have registered with our system) in a given 60 day period. Of those around 17k were identified as running iOS (based on the browser user agent string). Please let me know if you have any further questions David David Morton Director, Mobile Communication Strategies University of Washington dmor...@u.washington.edumailto:dmor...@u.washington.edu tel 206.221.7814 -- www.freshlymobile.com a fresh look at mobility -- On Aug 24, 2010, at 2:29 PM, j...@nww.commailto:j...@nww.com wrote: Thanks, David. I assume your WLAN is 11n? Do you mind telling me your vendor? 18,000 iOS devices?! Do you see any *potential* issues with, say, fairly high numbers of iPhone 4's concentrated in a given area of the WLAN? Also, someone raised the issue of IP address exhaustion (due in part, I think, to higher roaming/connecting/reconnecting) with smartphones and tablets. Are you seeing any issues around this? Regards, John Cox Senior Editor Network World From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of David R. Morton Sent: Tuesday, August 24, 2010 11:37 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDUmailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? John, Yea Apple isn't always the best at providing detailed stats. The iPhone 4 does do .11n in the 2.4GHz space with a 1x1 antenna (at least as far as I've seen). There should be a bit of performance increase over the older models due to a few efficiencies with 11n. We haven't run any detailed tests ourselves, but so far haven't seen any real issues. Also I've published some of our wifi usage stats (including iPhone) to my blog at www.freshlymobile.comhttp://www.freshlymobile.com (click on UW Mobile stats at the top for the most recent look). Take care David David Morton Director, Mobile Communication Strategies University of Washington dmor...@u.washington.edumailto:dmor...@u.washington.edu tel 206.221.7814 -- www.freshlymobile.comhttp://www.freshlymobile.com a fresh look at mobility -- On Aug 24, 2010, at 8:03 AM, j...@nww.commailto:j...@nww.com wrote: Stan, What kind of 11n data rates and throughput are you seeing in the 2.4 band? Also, I think iPhone 4 has only a single Wi-Fi antenna, so it doesn't benefit (or benefit as much) as a 2x2 or 3x3 MIMO laptop. Have you done any i4 performance metrics? I'm trying to get 11n implementation details from Apple, but so far they've only referred me to the Web i4 spec sheet. Regards, John Cox Senior Editor Network World From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Brooks, Stan Sent: Tuesday, August 24, 2010 11:00 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDUmailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? John, At Emory University, we've just completed upgrading our ResHalls to 802.11n and are now working on our academic buildings as part of a system-wide upgrade to 802.11n. We've moved from single radio b/g APs to dual radio a/b/g/n APs. We are running 802.11n (backwards compatible to b/g) on our 2.4GHz radios, but without the 40MHz (high-throughput) channel plan. In fact I (and most wireless engineers) would advise against running 40MHz channels at 2.4GHz. We do run the 40MHz channels in the 5GHz band, however. That said, 802.11n with standard 20MHz channels does give
Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n?
John, I think the only issue is that .11n devices will loose some performance having to share the band with .11g/b devices. Currently we run about a 50-50 split on the 2.4 band between .11n and .11g devices with no particular problems. -Chris On Aug 24, 2010, at 10:08 AM, j...@nww.commailto:j...@nww.com j...@nww.commailto:j...@nww.com wrote: Chris, Thanks. Your observation on 40Mhz limiting the channel options in 2.4 band fits with what I've learned also. As I mentioned in my direct reply, your email reminded me -- and I should have thought of this -- that of course the same 3-channel limitation exists for 11b/g iPhones. But…what I'm wondering is if the iPhone 4's demand or preference for 11n makes the situation more problematic, especially in a mixed-client environment -- when b/g iPhones are associating to the same 11n access point? Regards, John Cox Senior Editor Network World From: Chris Murphy [mailto:ch...@mit.edu] Sent: Monday, August 23, 2010 7:28 PM To: The EDUCAUSE Wireless Issues Constituent Group Listserv Cc: John Cox Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? John, I don't think there is much of an issue here, unless there is a requirement that the iPhone 4's need the bandwidth possible using 40Mhz channels. Just about every design guideline I've seen, and every conversation I've had with engineers at various networking companies, considers using 40Mhz channels at 2.4Ghz to be a bad idea, due to the loss of what little flexibility one has with channel layout as well as with adverse effects on neighboring networks in crowded areas (the anti-social effect), so here at least we never considered it. -Chris On Aug 23, 2010, at 9:12 AM, mailto:j...@nww.comj...@nww.commailto:j...@nww.com mailto:j...@nww.comj...@nww.commailto:j...@nww.com wrote: Folks, I was talking to a higher education IT guy last week; they have a lot of iPhones, and are rollling out iPhone 4's to new freshman and to faculty. As part of this, they upgraded the campus WLAN to 802.11n. BUT, after iPhone 4 was announced, they realized its 11n support was ONLY for the 2.4 GHz band (with of course only 3 non-overlapping channels, and tradeoffs if you merge two of them into one 40MHz channel). In SOME locations, they're having to do some fancy juggling of access points, channel and power settings. Juggling 3 channels in a crowded location clearly is NOT new. But the fact that this is occurring in 11n with a popular client device that often relies on WLAN access, seems noteworthy. I was wondering if anyone else is running into similar issues with iPhone 4 and 11n? I'm going to be writing this up as a Network World story today or early Tuesday. If you're interested in emailing/talking briefly with me about this, please just copy any listserv response to (or email me directly at) my NW email: mailto:john_...@nww.com john_...@nww.commailto:john_...@nww.com. Thanks! Regards, John Cox __ J o h n C o x Senior Editor Main: 508.766.5301 | Direct: 508.766.5422 Office at home: 978-834-0554 NETWORKWORLD Maximize Your Return on IT 492 Old Connecticut Path | Framingham, MA 01701-9002 __ NetworkWorld.comhttp://www.networkworld.com/ | 2009 Media Guidehttp://www.networkworld.com/media/ | Conferences and Eventshttp://www.networkworld.com/events/ ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found athttp://www.educause.edu/groups/http://www.educause.edu/groups/. === Chris Murphy Network Engineer MIT Information Services Technology Room W92-191 77 Massachusetts Avenue Cambridge, MA 02139 mailto:ch...@mit.educh...@mit.edumailto:ch...@mit.edu ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
RE: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n?
John, At Emory University, we've just completed upgrading our ResHalls to 802.11n and are now working on our academic buildings as part of a system-wide upgrade to 802.11n. We've moved from single radio b/g APs to dual radio a/b/g/n APs. We are running 802.11n (backwards compatible to b/g) on our 2.4GHz radios, but without the 40MHz (high-throughput) channel plan. In fact I (and most wireless engineers) would advise against running 40MHz channels at 2.4GHz. We do run the 40MHz channels in the 5GHz band, however. That said, 802.11n with standard 20MHz channels does give marked improvement over 802.11b/g because of other dot11n technologies - multiple special streams, frame aggregation, etc. - Stan Brooks - CWNA/CWSP Emory University University Technology Services 404.727.0226 AIM/Y!/Twitter: WLANstan MSN: wlans...@hotmail.commailto:wlans...@hotmail.com GoogleTalk: wlans...@gmail.commailto:wlans...@gmail.com From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of j...@nww.com Sent: Tuesday, August 24, 2010 10:08 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? Chris, Thanks. Your observation on 40Mhz limiting the channel options in 2.4 band fits with what I've learned also. As I mentioned in my direct reply, your email reminded me -- and I should have thought of this -- that of course the same 3-channel limitation exists for 11b/g iPhones. But...what I'm wondering is if the iPhone 4's demand or preference for 11n makes the situation more problematic, especially in a mixed-client environment -- when b/g iPhones are associating to the same 11n access point? Regards, John Cox Senior Editor Network World From: Chris Murphy [mailto:ch...@mit.edu] Sent: Monday, August 23, 2010 7:28 PM To: The EDUCAUSE Wireless Issues Constituent Group Listserv Cc: John Cox Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? John, I don't think there is much of an issue here, unless there is a requirement that the iPhone 4's need the bandwidth possible using 40Mhz channels. Just about every design guideline I've seen, and every conversation I've had with engineers at various networking companies, considers using 40Mhz channels at 2.4Ghz to be a bad idea, due to the loss of what little flexibility one has with channel layout as well as with adverse effects on neighboring networks in crowded areas (the anti-social effect), so here at least we never considered it. -Chris On Aug 23, 2010, at 9:12 AM, j...@nww.commailto:j...@nww.com j...@nww.commailto:j...@nww.com wrote: Folks, I was talking to a higher education IT guy last week; they have a lot of iPhones, and are rollling out iPhone 4's to new freshman and to faculty. As part of this, they upgraded the campus WLAN to 802.11n. BUT, after iPhone 4 was announced, they realized its 11n support was ONLY for the 2.4 GHz band (with of course only 3 non-overlapping channels, and tradeoffs if you merge two of them into one 40MHz channel). In SOME locations, they're having to do some fancy juggling of access points, channel and power settings. Juggling 3 channels in a crowded location clearly is NOT new. But the fact that this is occurring in 11n with a popular client device that often relies on WLAN access, seems noteworthy. I was wondering if anyone else is running into similar issues with iPhone 4 and 11n? I'm going to be writing this up as a Network World story today or early Tuesday. If you're interested in emailing/talking briefly with me about this, please just copy any listserv response to (or email me directly at) my NW email: john_...@nww.commailto:john_...@nww.com. Thanks! Regards, John Cox __ J o h n C o x Senior Editor Main: 508.766.5301 | Direct: 508.766.5422 Office at home: 978-834-0554 NETWORKWORLD Maximize Your Return on IT 492 Old Connecticut Path | Framingham, MA 01701-9002 __ NetworkWorld.comhttp://www.networkworld.com/ | 2009 Media Guidehttp://www.networkworld.com/media/ | Conferences and Eventshttp://www.networkworld.com/events/ ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found athttp://www.educause.edu/groups/. === Chris Murphy Network Engineer MIT Information Services Technology Room W92-191 77 Massachusetts Avenue Cambridge, MA 02139 ch...@mit.edumailto:ch...@mit.edu ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. This e-mail message (including any attachments) is for the sole use of the intended recipient(s) and may contain confidential and privileged
RE: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n?
Stan, What kind of 11n data rates and throughput are you seeing in the 2.4 band? Also, I think iPhone 4 has only a single Wi-Fi antenna, so it doesn't benefit (or benefit as much) as a 2x2 or 3x3 MIMO laptop. Have you done any i4 performance metrics? I'm trying to get 11n implementation details from Apple, but so far they've only referred me to the Web i4 spec sheet. Regards, John Cox Senior Editor Network World From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Brooks, Stan Sent: Tuesday, August 24, 2010 11:00 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? John, At Emory University, we've just completed upgrading our ResHalls to 802.11n and are now working on our academic buildings as part of a system-wide upgrade to 802.11n. We've moved from single radio b/g APs to dual radio a/b/g/n APs. We are running 802.11n (backwards compatible to b/g) on our 2.4GHz radios, but without the 40MHz (high-throughput) channel plan. In fact I (and most wireless engineers) would advise against running 40MHz channels at 2.4GHz. We do run the 40MHz channels in the 5GHz band, however. That said, 802.11n with standard 20MHz channels does give marked improvement over 802.11b/g because of other dot11n technologies - multiple special streams, frame aggregation, etc. - Stan Brooks - CWNA/CWSP Emory University University Technology Services 404.727.0226 AIM/Y!/Twitter: WLANstan MSN: wlans...@hotmail.commailto:wlans...@hotmail.com GoogleTalk: wlans...@gmail.commailto:wlans...@gmail.com From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of j...@nww.com Sent: Tuesday, August 24, 2010 10:08 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? Chris, Thanks. Your observation on 40Mhz limiting the channel options in 2.4 band fits with what I've learned also. As I mentioned in my direct reply, your email reminded me -- and I should have thought of this -- that of course the same 3-channel limitation exists for 11b/g iPhones. But...what I'm wondering is if the iPhone 4's demand or preference for 11n makes the situation more problematic, especially in a mixed-client environment -- when b/g iPhones are associating to the same 11n access point? Regards, John Cox Senior Editor Network World From: Chris Murphy [mailto:ch...@mit.edu] Sent: Monday, August 23, 2010 7:28 PM To: The EDUCAUSE Wireless Issues Constituent Group Listserv Cc: John Cox Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? John, I don't think there is much of an issue here, unless there is a requirement that the iPhone 4's need the bandwidth possible using 40Mhz channels. Just about every design guideline I've seen, and every conversation I've had with engineers at various networking companies, considers using 40Mhz channels at 2.4Ghz to be a bad idea, due to the loss of what little flexibility one has with channel layout as well as with adverse effects on neighboring networks in crowded areas (the anti-social effect), so here at least we never considered it. -Chris On Aug 23, 2010, at 9:12 AM, j...@nww.commailto:j...@nww.com j...@nww.commailto:j...@nww.com wrote: Folks, I was talking to a higher education IT guy last week; they have a lot of iPhones, and are rollling out iPhone 4's to new freshman and to faculty. As part of this, they upgraded the campus WLAN to 802.11n. BUT, after iPhone 4 was announced, they realized its 11n support was ONLY for the 2.4 GHz band (with of course only 3 non-overlapping channels, and tradeoffs if you merge two of them into one 40MHz channel). In SOME locations, they're having to do some fancy juggling of access points, channel and power settings. Juggling 3 channels in a crowded location clearly is NOT new. But the fact that this is occurring in 11n with a popular client device that often relies on WLAN access, seems noteworthy. I was wondering if anyone else is running into similar issues with iPhone 4 and 11n? I'm going to be writing this up as a Network World story today or early Tuesday. If you're interested in emailing/talking briefly with me about this, please just copy any listserv response to (or email me directly at) my NW email: john_...@nww.commailto:john_...@nww.com. Thanks! Regards, John Cox __ J o h n C o x Senior Editor Main: 508.766.5301 | Direct: 508.766.5422 Office at home: 978-834-0554 NETWORKWORLD Maximize Your Return on IT 492 Old Connecticut Path | Framingham, MA 01701-9002 __ NetworkWorld.comhttp://www.networkworld.com/ | 2009 Media Guidehttp://www.networkworld.com/media/ | Conferences and Eventshttp://www.networkworld.com
RE: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n?
Good point, John. The iPhone is only a 1x1 MiMo, so no special stream boost. There is still the reduced guard time and frame aggregation that will give better performance compared to 802.11b/g. I'm still digging out from (a very successful) Back-to-School weekend, but we are seeing approximately 1/3 of our total ResNet users running 802.11n in 5GHz, 1/3 running 802.11n in 2.4GHz, and 1/3 running 802.11g. I don't have any breakout for the iPhones specifically but can say that iDevices (iPads, iPhones, iPod Touches) accounted for a little over 8% or our total clients registered over the weekend. - Stan Brooks - CWNA/CWSP Emory University University Technology Services 404.727.0226 AIM/Y!/Twitter: WLANstan MSN: wlans...@hotmail.commailto:wlans...@hotmail.com GoogleTalk: wlans...@gmail.commailto:wlans...@gmail.com From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of j...@nww.com Sent: Tuesday, August 24, 2010 11:04 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? Stan, What kind of 11n data rates and throughput are you seeing in the 2.4 band? Also, I think iPhone 4 has only a single Wi-Fi antenna, so it doesn't benefit (or benefit as much) as a 2x2 or 3x3 MIMO laptop. Have you done any i4 performance metrics? I'm trying to get 11n implementation details from Apple, but so far they've only referred me to the Web i4 spec sheet. Regards, John Cox Senior Editor Network World From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Brooks, Stan Sent: Tuesday, August 24, 2010 11:00 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? John, At Emory University, we've just completed upgrading our ResHalls to 802.11n and are now working on our academic buildings as part of a system-wide upgrade to 802.11n. We've moved from single radio b/g APs to dual radio a/b/g/n APs. We are running 802.11n (backwards compatible to b/g) on our 2.4GHz radios, but without the 40MHz (high-throughput) channel plan. In fact I (and most wireless engineers) would advise against running 40MHz channels at 2.4GHz. We do run the 40MHz channels in the 5GHz band, however. That said, 802.11n with standard 20MHz channels does give marked improvement over 802.11b/g because of other dot11n technologies - multiple special streams, frame aggregation, etc. - Stan Brooks - CWNA/CWSP Emory University University Technology Services 404.727.0226 AIM/Y!/Twitter: WLANstan MSN: wlans...@hotmail.commailto:wlans...@hotmail.com GoogleTalk: wlans...@gmail.commailto:wlans...@gmail.com From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of j...@nww.com Sent: Tuesday, August 24, 2010 10:08 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? Chris, Thanks. Your observation on 40Mhz limiting the channel options in 2.4 band fits with what I've learned also. As I mentioned in my direct reply, your email reminded me -- and I should have thought of this -- that of course the same 3-channel limitation exists for 11b/g iPhones. But...what I'm wondering is if the iPhone 4's demand or preference for 11n makes the situation more problematic, especially in a mixed-client environment -- when b/g iPhones are associating to the same 11n access point? Regards, John Cox Senior Editor Network World From: Chris Murphy [mailto:ch...@mit.edu] Sent: Monday, August 23, 2010 7:28 PM To: The EDUCAUSE Wireless Issues Constituent Group Listserv Cc: John Cox Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? John, I don't think there is much of an issue here, unless there is a requirement that the iPhone 4's need the bandwidth possible using 40Mhz channels. Just about every design guideline I've seen, and every conversation I've had with engineers at various networking companies, considers using 40Mhz channels at 2.4Ghz to be a bad idea, due to the loss of what little flexibility one has with channel layout as well as with adverse effects on neighboring networks in crowded areas (the anti-social effect), so here at least we never considered it. -Chris On Aug 23, 2010, at 9:12 AM, j...@nww.commailto:j...@nww.com j...@nww.commailto:j...@nww.com wrote: Folks, I was talking to a higher education IT guy last week; they have a lot of iPhones, and are rollling out iPhone 4's to new freshman and to faculty. As part of this, they upgraded the campus WLAN to 802.11n. BUT, after iPhone 4 was announced, they realized its 11n support was ONLY for the 2.4 GHz band (with of course only 3 non-overlapping channels, and tradeoffs if you merge two of them into one 40MHz
Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n?
John, Yea Apple isn't always the best at providing detailed stats. The iPhone 4 does do .11n in the 2.4GHz space with a 1x1 antenna (at least as far as I've seen). There should be a bit of performance increase over the older models due to a few efficiencies with 11n. We haven't run any detailed tests ourselves, but so far haven't seen any real issues. Also I've published some of our wifi usage stats (including iPhone) to my blog at www.freshlymobile.comhttp://www.freshlymobile.com (click on UW Mobile stats at the top for the most recent look). Take care David David Morton Director, Mobile Communication Strategies University of Washington dmor...@u.washington.edumailto:dmor...@u.washington.edu tel 206.221.7814 -- www.freshlymobile.com a fresh look at mobility -- On Aug 24, 2010, at 8:03 AM, j...@nww.commailto:j...@nww.com wrote: Stan, What kind of 11n data rates and throughput are you seeing in the 2.4 band? Also, I think iPhone 4 has only a single Wi-Fi antenna, so it doesn't benefit (or benefit as much) as a 2x2 or 3x3 MIMO laptop. Have you done any i4 performance metrics? I'm trying to get 11n implementation details from Apple, but so far they've only referred me to the Web i4 spec sheet. Regards, John Cox Senior Editor Network World From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Brooks, Stan Sent: Tuesday, August 24, 2010 11:00 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDUmailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? John, At Emory University, we’ve just completed upgrading our ResHalls to 802.11n and are now working on our academic buildings as part of a system-wide upgrade to 802.11n. We’ve moved from single radio b/g APs to dual radio a/b/g/n APs. We are running 802.11n (backwards compatible to b/g) on our 2.4GHz radios, but without the 40MHz (high-throughput) channel plan. In fact I (and most wireless engineers) would advise against running 40MHz channels at 2.4GHz. We do run the 40MHz channels in the 5GHz band, however. That said, 802.11n with standard 20MHz channels does give marked improvement over 802.11b/g because of other dot11n technologies – multiple special streams, frame aggregation, etc. - Stan Brooks - CWNA/CWSP Emory University University Technology Services 404.727.0226 AIM/Y!/Twitter: WLANstan MSN: wlans...@hotmail.commailto:wlans...@hotmail.com GoogleTalk: wlans...@gmail.commailto:wlans...@gmail.com From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of j...@nww.commailto:j...@nww.com Sent: Tuesday, August 24, 2010 10:08 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDUmailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? Chris, Thanks. Your observation on 40Mhz limiting the channel options in 2.4 band fits with what I've learned also. As I mentioned in my direct reply, your email reminded me -- and I should have thought of this -- that of course the same 3-channel limitation exists for 11b/g iPhones. But…what I'm wondering is if the iPhone 4's demand or preference for 11n makes the situation more problematic, especially in a mixed-client environment -- when b/g iPhones are associating to the same 11n access point? Regards, John Cox Senior Editor Network World From: Chris Murphy [mailto:ch...@mit.edu] Sent: Monday, August 23, 2010 7:28 PM To: The EDUCAUSE Wireless Issues Constituent Group Listserv Cc: John Cox Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? John, I don't think there is much of an issue here, unless there is a requirement that the iPhone 4's need the bandwidth possible using 40Mhz channels. Just about every design guideline I've seen, and every conversation I've had with engineers at various networking companies, considers using 40Mhz channels at 2.4Ghz to be a bad idea, due to the loss of what little flexibility one has with channel layout as well as with adverse effects on neighboring networks in crowded areas (the anti-social effect), so here at least we never considered it. -Chris On Aug 23, 2010, at 9:12 AM, j...@nww.commailto:j...@nww.com j...@nww.commailto:j...@nww.com wrote: Folks, I was talking to a higher education IT guy last week; they have a lot of iPhones, and are rollling out iPhone 4's to new freshman and to faculty. As part of this, they upgraded the campus WLAN to 802.11n. BUT, after iPhone 4 was announced, they realized its 11n support was ONLY for the 2.4 GHz band (with of course only 3 non-overlapping channels, and tradeoffs if you merge two of them into one 40MHz channel). In SOME locations, they're having to do some fancy juggling of access points
RE: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n?
Thanks, Chris. Any idea what kind of WLAN throughput your iPhone 4 clients are getting? Regards, John Cox Senior Editor Network World From: Chris Murphy [mailto:ch...@mit.edu] Sent: Tuesday, August 24, 2010 10:26 AM To: The EDUCAUSE Wireless Issues Constituent Group Listserv Cc: WIRELESS-LAN@listserv.educause.edu; John Cox Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? John, I think the only issue is that .11n devices will loose some performance having to share the band with .11g/b devices. Currently we run about a 50-50 split on the 2.4 band between .11n and .11g devices with no particular problems. -Chris On Aug 24, 2010, at 10:08 AM, j...@nww.commailto:j...@nww.com j...@nww.commailto:j...@nww.com wrote: Chris, Thanks. Your observation on 40Mhz limiting the channel options in 2.4 band fits with what I've learned also. As I mentioned in my direct reply, your email reminded me -- and I should have thought of this -- that of course the same 3-channel limitation exists for 11b/g iPhones. But…what I'm wondering is if the iPhone 4's demand or preference for 11n makes the situation more problematic, especially in a mixed-client environment -- when b/g iPhones are associating to the same 11n access point? Regards, John Cox Senior Editor Network World From: Chris Murphy [mailto:ch...@mit.edu] Sent: Monday, August 23, 2010 7:28 PM To: The EDUCAUSE Wireless Issues Constituent Group Listserv Cc: John Cox Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? John, I don't think there is much of an issue here, unless there is a requirement that the iPhone 4's need the bandwidth possible using 40Mhz channels. Just about every design guideline I've seen, and every conversation I've had with engineers at various networking companies, considers using 40Mhz channels at 2.4Ghz to be a bad idea, due to the loss of what little flexibility one has with channel layout as well as with adverse effects on neighboring networks in crowded areas (the anti-social effect), so here at least we never considered it. -Chris On Aug 23, 2010, at 9:12 AM, j...@nww.commailto:j...@nww.com j...@nww.commailto:j...@nww.com wrote: Folks, I was talking to a higher education IT guy last week; they have a lot of iPhones, and are rollling out iPhone 4's to new freshman and to faculty. As part of this, they upgraded the campus WLAN to 802.11n. BUT, after iPhone 4 was announced, they realized its 11n support was ONLY for the 2.4 GHz band (with of course only 3 non-overlapping channels, and tradeoffs if you merge two of them into one 40MHz channel). In SOME locations, they're having to do some fancy juggling of access points, channel and power settings. Juggling 3 channels in a crowded location clearly is NOT new. But the fact that this is occurring in 11n with a popular client device that often relies on WLAN access, seems noteworthy. I was wondering if anyone else is running into similar issues with iPhone 4 and 11n? I'm going to be writing this up as a Network World story today or early Tuesday. If you're interested in emailing/talking briefly with me about this, please just copy any listserv response to (or email me directly at) my NW email: john_...@nww.commailto:john_...@nww.com. Thanks! Regards, John Cox __ J o h n C o x Senior Editor Main: 508.766.5301 | Direct: 508.766.5422 Office at home: 978-834-0554 NETWORKWORLD Maximize Your Return on IT 492 Old Connecticut Path | Framingham, MA 01701-9002 __ NetworkWorld.comhttp://www.networkworld.com/ | 2009 Media Guidehttp://www.networkworld.com/media/ | Conferences and Eventshttp://www.networkworld.com/events/ ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found athttp://www.educause.edu/groups/. === Chris Murphy Network Engineer MIT Information Services Technology Room W92-191 77 Massachusetts Avenue Cambridge, MA 02139 ch...@mit.edumailto:ch...@mit.edu ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
RE: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n?
Thanks, Stan. Congrats on the weekend's success! Regards, John Cox Senior Editor Network World From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Brooks, Stan Sent: Tuesday, August 24, 2010 11:28 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? Good point, John. The iPhone is only a 1x1 MiMo, so no special stream boost. There is still the reduced guard time and frame aggregation that will give better performance compared to 802.11b/g. I'm still digging out from (a very successful) Back-to-School weekend, but we are seeing approximately 1/3 of our total ResNet users running 802.11n in 5GHz, 1/3 running 802.11n in 2.4GHz, and 1/3 running 802.11g. I don't have any breakout for the iPhones specifically but can say that iDevices (iPads, iPhones, iPod Touches) accounted for a little over 8% or our total clients registered over the weekend. - Stan Brooks - CWNA/CWSP Emory University University Technology Services 404.727.0226 AIM/Y!/Twitter: WLANstan MSN: wlans...@hotmail.commailto:wlans...@hotmail.com GoogleTalk: wlans...@gmail.commailto:wlans...@gmail.com From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of j...@nww.com Sent: Tuesday, August 24, 2010 11:04 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? Stan, What kind of 11n data rates and throughput are you seeing in the 2.4 band? Also, I think iPhone 4 has only a single Wi-Fi antenna, so it doesn't benefit (or benefit as much) as a 2x2 or 3x3 MIMO laptop. Have you done any i4 performance metrics? I'm trying to get 11n implementation details from Apple, but so far they've only referred me to the Web i4 spec sheet. Regards, John Cox Senior Editor Network World From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Brooks, Stan Sent: Tuesday, August 24, 2010 11:00 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? John, At Emory University, we've just completed upgrading our ResHalls to 802.11n and are now working on our academic buildings as part of a system-wide upgrade to 802.11n. We've moved from single radio b/g APs to dual radio a/b/g/n APs. We are running 802.11n (backwards compatible to b/g) on our 2.4GHz radios, but without the 40MHz (high-throughput) channel plan. In fact I (and most wireless engineers) would advise against running 40MHz channels at 2.4GHz. We do run the 40MHz channels in the 5GHz band, however. That said, 802.11n with standard 20MHz channels does give marked improvement over 802.11b/g because of other dot11n technologies - multiple special streams, frame aggregation, etc. - Stan Brooks - CWNA/CWSP Emory University University Technology Services 404.727.0226 AIM/Y!/Twitter: WLANstan MSN: wlans...@hotmail.commailto:wlans...@hotmail.com GoogleTalk: wlans...@gmail.commailto:wlans...@gmail.com From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of j...@nww.com Sent: Tuesday, August 24, 2010 10:08 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? Chris, Thanks. Your observation on 40Mhz limiting the channel options in 2.4 band fits with what I've learned also. As I mentioned in my direct reply, your email reminded me -- and I should have thought of this -- that of course the same 3-channel limitation exists for 11b/g iPhones. But...what I'm wondering is if the iPhone 4's demand or preference for 11n makes the situation more problematic, especially in a mixed-client environment -- when b/g iPhones are associating to the same 11n access point? Regards, John Cox Senior Editor Network World From: Chris Murphy [mailto:ch...@mit.edu] Sent: Monday, August 23, 2010 7:28 PM To: The EDUCAUSE Wireless Issues Constituent Group Listserv Cc: John Cox Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? John, I don't think there is much of an issue here, unless there is a requirement that the iPhone 4's need the bandwidth possible using 40Mhz channels. Just about every design guideline I've seen, and every conversation I've had with engineers at various networking companies, considers using 40Mhz channels at 2.4Ghz to be a bad idea, due to the loss of what little flexibility one has with channel layout as well as with adverse effects on neighboring networks in crowded areas (the anti-social effect), so here at least we never considered it. -Chris On Aug 23, 2010, at 9:12 AM, j...@nww.commailto:j...@nww.com j...@nww.commailto:j...@nww.com wrote: Folks, I was talking to a higher
RE: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n?
Thanks, David. I assume your WLAN is 11n? Do you mind telling me your vendor? 18,000 iOS devices?! Do you see any *potential* issues with, say, fairly high numbers of iPhone 4's concentrated in a given area of the WLAN? Also, someone raised the issue of IP address exhaustion (due in part, I think, to higher roaming/connecting/reconnecting) with smartphones and tablets. Are you seeing any issues around this? Regards, John Cox Senior Editor Network World From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of David R. Morton Sent: Tuesday, August 24, 2010 11:37 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? John, Yea Apple isn't always the best at providing detailed stats. The iPhone 4 does do .11n in the 2.4GHz space with a 1x1 antenna (at least as far as I've seen). There should be a bit of performance increase over the older models due to a few efficiencies with 11n. We haven't run any detailed tests ourselves, but so far haven't seen any real issues. Also I've published some of our wifi usage stats (including iPhone) to my blog at www.freshlymobile.comhttp://www.freshlymobile.com (click on UW Mobile stats at the top for the most recent look). Take care David David Morton Director, Mobile Communication Strategies University of Washington dmor...@u.washington.edumailto:dmor...@u.washington.edu tel 206.221.7814 -- www.freshlymobile.com a fresh look at mobility -- On Aug 24, 2010, at 8:03 AM, j...@nww.commailto:j...@nww.com wrote: Stan, What kind of 11n data rates and throughput are you seeing in the 2.4 band? Also, I think iPhone 4 has only a single Wi-Fi antenna, so it doesn't benefit (or benefit as much) as a 2x2 or 3x3 MIMO laptop. Have you done any i4 performance metrics? I'm trying to get 11n implementation details from Apple, but so far they've only referred me to the Web i4 spec sheet. Regards, John Cox Senior Editor Network World From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Brooks, Stan Sent: Tuesday, August 24, 2010 11:00 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDUmailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? John, At Emory University, we've just completed upgrading our ResHalls to 802.11n and are now working on our academic buildings as part of a system-wide upgrade to 802.11n. We've moved from single radio b/g APs to dual radio a/b/g/n APs. We are running 802.11n (backwards compatible to b/g) on our 2.4GHz radios, but without the 40MHz (high-throughput) channel plan. In fact I (and most wireless engineers) would advise against running 40MHz channels at 2.4GHz. We do run the 40MHz channels in the 5GHz band, however. That said, 802.11n with standard 20MHz channels does give marked improvement over 802.11b/g because of other dot11n technologies - multiple special streams, frame aggregation, etc. - Stan Brooks - CWNA/CWSP Emory University University Technology Services 404.727.0226 AIM/Y!/Twitter: WLANstan MSN: wlans...@hotmail.commailto:wlans...@hotmail.com GoogleTalk: wlans...@gmail.commailto:wlans...@gmail.com From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of j...@nww.commailto:j...@nww.com Sent: Tuesday, August 24, 2010 10:08 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDUmailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? Chris, Thanks. Your observation on 40Mhz limiting the channel options in 2.4 band fits with what I've learned also. As I mentioned in my direct reply, your email reminded me -- and I should have thought of this -- that of course the same 3-channel limitation exists for 11b/g iPhones. But...what I'm wondering is if the iPhone 4's demand or preference for 11n makes the situation more problematic, especially in a mixed-client environment -- when b/g iPhones are associating to the same 11n access point? Regards, John Cox Senior Editor Network World From: Chris Murphy [mailto:ch...@mit.edu] Sent: Monday, August 23, 2010 7:28 PM To: The EDUCAUSE Wireless Issues Constituent Group Listserv Cc: John Cox Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? John, I don't think there is much of an issue here, unless there is a requirement that the iPhone 4's need the bandwidth possible using 40Mhz channels. Just about every design guideline I've seen, and every conversation I've had with engineers at various networking companies, considers using 40Mhz channels at 2.4Ghz to be a bad idea, due to the loss of what little flexibility one has with channel layout as well
Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n?
John, On my Cisco 802.11n deployment, both an iPhone 4 or iPad average about 28Mbs against various bandwidth testers. Jeff Jeffrey D Sessler Director Information Technology Scripps College 08/24/10 2:20 PM Thanks, Chris. Any idea what kind of WLAN throughput your iPhone 4 clients are getting? Regards, John Cox Senior Editor Network World From: Chris Murphy [mailto:ch...@mit.edu] Sent: Tuesday, August 24, 2010 10:26 AM To: The EDUCAUSE Wireless Issues Constituent Group Listserv Cc: WIRELESS-LAN@listserv.educause.edu; John Cox Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? John, I think the only issue is that .11n devices will loose some performance having to share the band with .11g/b devices. Currently we run about a 50-50 split on the 2.4 band between .11n and .11g devices with no particular problems. -Chris On Aug 24, 2010, at 10:08 AM, j...@nww.com wrote: Chris, Thanks. Your observation on 40Mhz limiting the channel options in 2.4 band fits with what I've learned also. As I mentioned in my direct reply, your email reminded me -- and I should have thought of this -- that of course the same 3-channel limitation exists for 11b/g iPhones. But…what I'm wondering is if the iPhone 4's demand or preference for 11n makes the situation more problematic, especially in a mixed-client environment -- when b/g iPhones are associating to the same 11n access point? Regards, John Cox Senior Editor Network World From: Chris Murphy [mailto:ch...@mit.edu] Sent: Monday, August 23, 2010 7:28 PM To: The EDUCAUSE Wireless Issues Constituent Group Listserv Cc: John Cox Subject: Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n? John, I don't think there is much of an issue here, unless there is a requirement that the iPhone 4's need the bandwidth possible using 40Mhz channels. Just about every design guideline I've seen, and every conversation I've had with engineers at various networking companies, considers using 40Mhz channels at 2.4Ghz to be a bad idea, due to the loss of what little flexibility one has with channel layout as well as with adverse effects on neighboring networks in crowded areas (the anti-social effect), so here at least we never considered it. -Chris On Aug 23, 2010, at 9:12 AM, wrote: Folks, I was talking to a higher education IT guy last week; they have a lot of iPhones, and are rollling out iPhone 4's to new freshman and to faculty. As part of this, they upgraded the campus WLAN to 802.11n. BUT, after iPhone 4 was announced, they realized its 11n support was ONLY for the 2.4 GHz band (with of course only 3 non-overlapping channels, and tradeoffs if you merge two of them into one 40MHz channel). In SOME locations, they're having to do some fancy juggling of access points, channel and power settings. Juggling 3 channels in a crowded location clearly is NOT new. But the fact that this is occurring in 11n with a popular client device that often relies on WLAN access, seems noteworthy. I was wondering if anyone else is running into similar issues with iPhone 4 and 11n? I'm going to be writing this up as a Network World story today or early Tuesday. If you're interested in emailing/talking briefly with me about this, please just copy any listserv response to (or email me directly at) my NW email: john_...@nww.com. Thanks! Regards, John Cox __ J o h n C o x Senior Editor Main: 508.766.5301 | Direct: 508.766.5422 Office at home: 978-834-0554 NETWORKWORLD Maximize Your Return on IT 492 Old Connecticut Path | Framingham, MA 01701-9002 __ NetworkWorld.com | 2009 Media Guide | Conferences and Events ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found athttp://www.educause.edu/groups/. ==ch...@mit.edu ** 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/.
Re: [WIRELESS-LAN] Any issues with iPhone 4 and 2.4GHz 802.11n?
John, I don't think there is much of an issue here, unless there is a requirement that the iPhone 4's need the bandwidth possible using 40Mhz channels. Just about every design guideline I've seen, and every conversation I've had with engineers at various networking companies, considers using 40Mhz channels at 2.4Ghz to be a bad idea, due to the loss of what little flexibility one has with channel layout as well as with adverse effects on neighboring networks in crowded areas (the anti-social effect), so here at least we never considered it. -Chris On Aug 23, 2010, at 9:12 AM, j...@nww.commailto:j...@nww.com j...@nww.commailto:j...@nww.com wrote: Folks, I was talking to a higher education IT guy last week; they have a lot of iPhones, and are rollling out iPhone 4's to new freshman and to faculty. As part of this, they upgraded the campus WLAN to 802.11n. BUT, after iPhone 4 was announced, they realized its 11n support was ONLY for the 2.4 GHz band (with of course only 3 non-overlapping channels, and tradeoffs if you merge two of them into one 40MHz channel). In SOME locations, they're having to do some fancy juggling of access points, channel and power settings. Juggling 3 channels in a crowded location clearly is NOT new. But the fact that this is occurring in 11n with a popular client device that often relies on WLAN access, seems noteworthy. I was wondering if anyone else is running into similar issues with iPhone 4 and 11n? I'm going to be writing this up as a Network World story today or early Tuesday. If you're interested in emailing/talking briefly with me about this, please just copy any listserv response to (or email me directly at) my NW email: john_...@nww.commailto:john_...@nww.com. Thanks! Regards, John Cox __ J o h n C o x Senior Editor Main: 508.766.5301 | Direct: 508.766.5422 Office at home: 978-834-0554 NETWORKWORLD Maximize Your Return on IT 492 Old Connecticut Path | Framingham, MA 01701-9002 __ NetworkWorld.comhttp://www.networkworld.com/ | 2009 Media Guidehttp://www.networkworld.com/media/ | Conferences and Eventshttp://www.networkworld.com/events/ ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found athttp://www.educause.edu/groups/. === Chris Murphy Network Engineer MIT Information Services Technology Room W92-191 77 Massachusetts Avenue Cambridge, MA 02139 ch...@mit.edumailto:ch...@mit.edu ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
