RE: [WIRELESS-LAN] AW: [WIRELESS-LAN] To provide (wireless) service, or not to provide (wireless) service...
When I was a program director recruiting undergrads at Syracuse, I used to get some questions about wireless networking services on campus, questions I welcomed because Morrissey, Badman, and Boardman have done a great job building out our network. It was a differentiator for us. These types of questions don’t get asked as much anymore. People just assume there is good campus Wi-Fi service. In fact, to most people, they wonder, what’s the big deal? If we can have good Wi-Fi at home, a prestigious University should be able to do the same. I’ve thought about explaining co-channel interference to them, but I don’t think that would help. As for students reporting problems with wireless, I’ve been administering a pre-course survey the past few years in my intro networking course, about 120 students. The question asks them what they do when they encounter a wireless network problem. Over 75% select the answer: “I do something else and try again later.” That helps explain why problems don’t get reported, despite Lee’s pleas to them to report problems when he visits my class. Oh, and by the way, I really like the students who answer: “I ping the default gateway address.” They usually do well in the course. dm -- Dave Molta Associate Professor of Practice Syracuse University School of Information Studies email: djmo...@syr.edu phone: 315-443-4549 From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Coehoorn, Joel Sent: Thursday, May 14, 2015 12:22 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] AW: [WIRELESS-LAN] To provide (wireless) service, or not to provide (wireless) service... I'll add another anecdotal viewpoint that I don't think anyone chooses to go to a specific school because of the wireless. I do think a student may choose NOT to go to a specific school if the student has a bad wireless experience. A candidate is more likely to assume the wifi works, and their one bad experience is an aberration, unless it happens repeatedly or they hear other students complain about it. A simple, Yeah, it's always like that comment. and suddenly a candidate goes elsewhere, but unless that happens wifi just isn't on a candidate's radar. Even if it is, many high schooler's don't yet have their own laptops (it's becoming a common graduation present), and will instead rely on a phone that has a backup data plan. This is especially true on a campus visit. Many candidate may never even try to connect to your network before arriving as a student for the first time. A current student will know better (or think they know better) by the end of the their first term. A single bad experience here or there typically won't matter much, but a consistently poor result may contribute to a transfer decision where wifi is one factor. I think wifi is rarely if ever the only factor, but the poorer the provided wifi service gets the more it has a potential to be a big factor. In other words, wifi service can translate over into the retention side of things, but teasing out just how much is challenging. The wifi service is important, but it's probably a mistake to try to build out the service to the level where you could see it as a competitive advantage over other institutions. As long as you don't fall significantly behind, you should be in good shape. Failing to provide service at all, though, is to risk falling significantly behind. Again, this is my anecdotal viewpoint. [http://www.york.edu/Portals/0/Images/Logo/YorkCollegeLogoSmall.jpg] Joel Coehoorn Director of Information Technology 402.363.5603tel:402.363.5603 jcoeho...@york.edumailto:jcoeho...@york.edu The mission of York College is to transform lives through Christ-centered education and to equip students for lifelong service to God, family, and society On Thu, May 14, 2015 at 10:33 AM, Chuck Enfield chu...@psu.edumailto:chu...@psu.edu wrote: I agree with the utility analogy, but what does that tell us? Not much, I think. Natural gas is also a utility, but request that in your office and see what kind of response you get. The utility analogy fails to answer many question related to how and where we should deliver Wi-Fi services. The answers to these questions must be driven by business requirements, and those are challenging to define. -Original Message- From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDUmailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Chuck Anderson Sent: Thursday, May 14, 2015 10:35 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDUmailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] AW: [WIRELESS-LAN] To provide (wireless) service, or not to provide (wireless) service... Wi-Fi has become an (expensive to maintain) utility. It is just expected to be there and work well. You don't have people going around asking how much of a deciding
RE: [WIRELESS-LAN] It would seem FCC just declared WLAN quarantine features illegal
While I understand the concerns of enterprise Wi-Fi managers, I think it would be difficult for the FCC to modify these rules in a way that protects everyone’s interests. One option might be for the FCC to redefine rules for 2.4 GHz such that only non-overlapping 20 MHz channels are permitted for non frequency hopping devices. That wouldn’t solve co-channel interference problems, but it would address the adjacent channel interference issues that cause the biggest problems. A few years ago, I had a couple students do some testing of the relative impact of co-channel and adjacent channel interference in the 2.4 GHz band. While the results weren’t conclusive (there are a lot of variables that are difficult to control for, especially the physical proximity of AP’s and client devices), they do show that you are better off with devices operating on the same channels than on adjacent channels: https://www.youtube.com/watch?v=1sbPPM93nbA The real question in my mind is why manufacturers of MyFi devices choose to configure the default to a channel other than 1, 6 or 11. We’ve seen a lot of devices defaulting to channel 2, which really messes up performance on channel 1. This obviously isn’t as much of an issue in the 5 GHz bands since we don’t have adjacent channel interference to contend with. In these situations, a MyFi device operating in your air-space doesn’t introduce significant interference issues. Assuming it complies with FCC rules (if it is certified by the FCC, it should), it just looks like another 802.11 device contending for air time. You could make the argument that a MyFi device configured for maximum output power may cause co-channel interference with other cells in a micro-cellular deployment but the same thing can be said for client devices that default to maximum radio output power. -- Dave Molta Associate Professor of Practice Syracuse University School of Information Studies email: djmo...@syr.edu phone: 315-443-4549 From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Peter P Morrissey Sent: Monday, October 27, 2014 7:27 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] It would seem FCC just declared WLAN quarantine features illegal That’s my point. If it isn’t my network, then it isn’t the MiFi owner’s network either. Pete Morrissey From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Tony Skalski Sent: Monday, October 27, 2014 7:18 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDUmailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] It would seem FCC just declared WLAN quarantine features illegal So isn’t the MiFi device essentially jamming your network and interrupting valid communications if it overlaps a nearby channel? No. It's not your network, in the sense that the wired infrastructure you built is. The wireless network uses a free to use, public, unlicensed RF spectrum. Yes you built the wireless infrastructure (APs and controllers), but the medium is fundamentally different. I've been working up a car analogy: if you were a urban university with buildings spread throughout a city, you couldn't deauth non-university vehicles from using the (publicly owned) roads (to ensure university owned vehicles could get to their destinations unimpeded). On Mon, Oct 27, 2014 at 6:06 PM, Peter P Morrissey ppmor...@syr.edumailto:ppmor...@syr.edu wrote: So isn’t the MiFi device essentially jamming your network and interrupting valid communications if it overlaps a nearby channel? Pete Morrissey From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDUmailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Thomas Carter Sent: Monday, October 27, 2014 5:18 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDUmailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] It would seem FCC just declared WLAN quarantine features illegal IANAL, but it seems the FCC is trying to regulate the “communications.” Sending a spoofed disassociate may not be jamming, but it is intentionally interrupting valid communications. They may see making something unusable through whatever means as equivalent to jamming. Thomas Carter Network and Operations Manager Austin College 903-813-2564tel:903-813-2564 [AusColl_Logo_Email] From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Pete Hoffswell Sent: Monday, October 27, 2014 4:05 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDUmailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] It would seem FCC just declared WLAN quarantine features illegal My thought is that the FCC is simply trying to police the ISM band, as outlined in FCC part 15 regulations
Re: [WIRELESS-LAN] 4-channels in 2.4 GHz
I had some students do a project this semester where they compared aggregate throughput on a standard 3-channel model and two alternative 4-channel models. This was Cisco 2-stream 11n, a single client running iXChariot downstream throughput test. 3-Channel (1,6,11) 185 Mbps 4-Channel (1,4,7,11) 153 Mbps 4-channel (1,4,8,11) 98 Mbps They also ran a 3-channel test, 4 AP's with two AP's on Channel 1, the other two on 6 and 11. The goal here was to assess the incremental improvement in capacity when two AP's are contending for use of a common channel. Aggregate throughput in that scenario was 160 Mbps but the thing that was most interesting about that test was that the two AP's did not share the channel evenly. One AP on Channel 1 got 58 Mbps of throughput while the other got 12 Mbps. These tests appear to support the hypothesis that adding more AP's in a dense configuration in the 2.4 Ghz band does not result in significant added capacity when AP's are experiencing co-channel interference. It is important to note that our tests focused on downstream throughput, which would probably be the worst-case scenario for co-channel interference. I had another team perform some testing of Ruckus' ChannelFly technology, which often uses non-standard channels. In that testing, we have noted modest improvements in performance compared to the classic 3-channel model. I'd be happy to share the report with people who are interested. Dave Molta From: Lee Badman lhbad...@syr.edumailto:lhbad...@syr.edu Reply-To: The EDUCAUSE Wireless Issues Constituent Group Listserv WIRELESS-LAN@LISTSERV.EDUCAUSE.EDUmailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Date: Tue, 8 May 2012 14:34:19 + To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDUmailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: [WIRELESS-LAN] 4-channels in 2.4 GHz With no intent to open a conversational can 'o worms, I'm curious if anyone is running a 4-channel plan on their production WLANs, that is willing to share their opinions and experiences on the topic. Thanks- Lee Lee H. Badman Wireless/Network Engineer, ITS Adjunct Instructor, iSchool Syracuse University 315.443.3003 ** 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] Wireless Site Survey cost
Wasted in what sense, Philippe? Residence halls are obviously high-density environments so capacity is a big concern, especially during peak usage periods. Even if the 5 GHz 11n channel can’t provide full coverage for the area under consideration, if it offloads even 25-30% of the 2.4 GHz 11n traffic, it seems like it would be worth the extra cost because it would result in better performance under heavy contention for both 2.4 GHz and 5 GHz users. Dave Molta On 3/22/11 3:59 PM, Hanset, Philippe C phan...@utk.edu wrote: Having done a Dorm Installation last week, let me add another point: 5 Ghz is great, but in some places you might want to skip the expense. We had no choice but to feed Dorm suites from the center hallway. After a thorough testing we came to the conclusion that we would only provide 802.11n at 2.4 GHz since too much of the 5 GHz signal was wasted. So instead of using Aruba AP-105 ($695 list) everywhere in that building, we settled for Aruba AP-93 ($395 list). With the savings, we did smaller cells to somewhat compensate for the lesser capacity. Each bedroom still has an ethernet drop (unfortunately unusable for APs for architectural reasons). Philippe Univ. of TN On Mar 22, 2011, at 3:38 PM, heath.barnhart wrote: If nothing else, you will have a documentation showing what your coverage is and can uncover any gotchas. If someone says they are having issues in an area, you pull up the survey and have instant access to more information to help uncover the reason behind their issues. Heath On 3/22/2011 2:11 PM, John Kaftan wrote: So I hate to dig this up again but nobody really responded to Jeff Sessler’s post “Given the need for designs based on capacity rather than coverage, do those who've done site surveys previously feel they are still worth the trouble?” Seems to me wireless surveys are for determining coverage which is something we can easily measure. We can require that an area will have no less than -68 dBm signal and do the survey to determine what it will take. However, if folks are saying that in a high density area like a ResHall just providing coverage is not enough and we must go much denser what good is the survey? If coverage is not enough then how do we determine our density? Is it just by feel? Up until now I figured I was not going to do a survey. I figured for the cost of the survey I could buy an additional 30-50 APs. When pulling wire I’d have facilities leave a 20’ coil and pull double the wire I originally guessed based on past experience. Then we would just “Throw it up” and see what happens. If we move slowly and do a ResHall at a time we should be able to get a feel for it. Now I have a shot at doing a survey this summer after the fact by using students from a nearby University that has a MS in Networking as an internship. The cost is much less than a professional survey but I have to ask if it is still worth it if capacity is what we are going for? Perhaps I should be looking at a different internship. There is certainly plenty to do around here. John Kaftan Infrastructure Manager Utica College 315.792.3102 From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of John Kaftan Sent: Wednesday, March 16, 2011 8:16 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Wireless Site Survey cost I have everyone held back to 2 Mbs on wireless. That seems to be a good number for now. Nobody is complaining and it helps to keep their experience consistent. They can watch a Netflix movie with that. I imagine Netflix would use more bandwidth if it could. I have not tested though. On 3/16/2011 6:28 PM, Brian Helman wrote: If people are building new dorms, I’d definitely run copper to any common rooms if you support any gaming consoles. Honestly though, we have a good density of wiring even in the dorms and I’m pretty close to shutting down or at least limiting the bandwidth available for video on the wireless network. Netflix, Flash and Youtube are killing it (not to mention our Internet connection). -Brian From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Joel Coehoorn Sent: Tuesday, March 15, 2011 10:30 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Wireless Site Survey cost Agree I wouldn't run new port-per-pillow drops, but I wouldn't ditch existing drops (just update the switching) and anywhere you have apartment-style living I would put a wired port in the common space for game consoles/blu-ray/smart tvs/etc. Those who actually use the ports will be the few who know enough to know why it's better, and they also tend to be your heaviest users. It's nice to get some of the gaming and netflix traffic out of your airspace. On Mar 15, 2011 7:50pm, John Kaftan jkaf...@utica.edu mailto:jkaf...@utica.edu wrote: Thanks,
Re: [WIRELESS-LAN] WiFi blockers in classrooms
As a faculty member who also closely follows developments in the wireless industry, I thought I would share my perspective. I teach an intro networking course to 120 students per semester. I try to edutain whenever possible but it is impossible for me to compete with the Internet for the attention of most students. Network guys/gals need to understand this. If you think you can command the attention of 120 students staring at laptops and smartphones in class, give me a call and I will hire you. I also know enough about wireless to know that dealing with this problem at the physical layer is probably not practical, for many reasons -- financial, technical, and behavioral. If there is any hope for a technical solution, I could envision a system that ties together class rosters, authentication, and location services. But even with that, you don't have any control over commercial wireless services. My current policy is no laptops or smartphones in class. I give students a 10-minute grace period at the start of class for urgent communication. Some students complain about this policy but the majority understand why I do this and feel it helps them focus on course content. The most valid complaint comes from students who take notes in class on their computer. I'm somewhat sympathetic to that, but if you've ever sat next to someone in a meeting who is taking notes on a laptop, you know that the keyboard clatter is distracting, sometimes infuriating. I encourage students to take notes by hand or record the lectures for later transcription, which helps with retention of course content. In my wireless course, which only has about 25-30 students, I have been more hesitant to implement a no-tolerance policy, but even there, I think the only way I could get away with that is to change my presentation style so that I spend more time in the back of the room checking screens and scolding abusers. Alas, one wonders whether there is a solution that will be acceptable to all. Last semester, our Dean implemented a no-laptop policy for faculty meetings, offering to reduce the meeting time by 30 minutes as an incentive. Before this policy, it was a very strange experience, with over half of the faculty attendees working away at their computers while we were supposed to be deliberating about important issues. The policy seemed to be working pretty well until the iPad was released. Now we have faculty coming to the meeting with iPads. It's not a laptop, right? dm Dave Molta Associate Professor Director, BS in Information Management and Technology Assistant Dean for Technology Syracuse University School of Information Studies 212 Hinds Hall Syracuse, NY 13244 315-443-4549 djmo...@syr.edu On 11/19/10 10:30 AM, Hanset, Philippe C phan...@utk.edu wrote: Luis, Cellular networks (usually licensed spectrum) are not under the same regulations as Wi-Fi (usually unlicensed spectrum). In the US, for instance, one cannot interfere with the licensed spectrum (jammers etc...), and when it comes to the unlicensed spectrum (e.g. Wi-Fi), you have to comply with Part15 of the FCC. Can you interfere with cellular networks in Nicaragua or Costa Rica? (I would double check...otherwise students will remind you!) The point I want to make with Cellular access (Macro towers, DAS, etc..), is that students that cannot join the Wi-Fi network in classrooms will find other wireless technologies to get access (Smartphones, tethering laptops, air-cards or just a book, but not the textbook!). So, students that can afford cellular-data access can still be distracted. This could be an interesting research. The hypothesis would be Is it about who you know or what you know or TextBook VS FaceBook ;-) Philippe Univ. of TN On Nov 19, 2010, at 9:45 AM, Luis Fernando Valverde wrote: Yes, we do.The idea is to block any source of wireless connection to the WiFi network. lf From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Hanset, Philippe C Sent: Jueves, 18 de Noviembre de 2010 07:42 p.m. To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] WiFi blockers in classrooms And do you plan to block air-cards on cellular as well with that jammer? Philippe Univ. of TN On Nov 18, 2010, at 4:06 PM, Luis Fernando Valverde wrote: I understand your points of view and I agree with some of your comments. However, we use our classrooms for multiple academic activities (MBA programs, seminar and in-company events), and we need to find a simple device to block the signal in a 10-20 meters radius / classroom. So, the adjacent classrooms can work with the signal of their own access points (some professors require Internet signal to teach their sessions – internet dynamics, simulations over the internet, cloud computing services, etc.). I have heard that this is implemented in some universities in the USA, Europe and Asia (for instance, I was told that in the
