I understand that reducing the transmit power reduces the range that devices can connect at particular data rates, what I was saying was that in practical terms, where I've had a requirement for a high density of users, I've generally found the distances from user to AP are not that big; i.e. a classroom or lecture hall. And turning transmit power down has very little effect unless the user density is spread across more than one room. I hadn't thought of removing some of the lower data rates though. Perhaps I've just not been brave enough in how low I've turned the transmit power!
5 Ghz is a bit of an issue for us as Air Traffic Control cuts across a big swathe of the 5 Ghz range, also a lot of devices ship with 802.11a disabled in the driver, or just with 802.11b/g radios, hopefully as our student population refreshes they'll have newer devices which are 802.11n and therefore inherently 2.4 Ghz and 5 Ghz capable J. Many Thanks Peter Peter Methven. MBCS, BENG (Hons) Network Specialist Computer Centre (The Allen McTernan Building) Heriot-Watt University Edinburgh EH14 4AS Telephone: +44 (0)131 4513516 / 07774 427548 Email [email protected] <mailto:[email protected]> From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:[email protected]] On Behalf Of Ryan Holland Sent: 11 August 2009 16:42 To: [email protected] Subject: Re: [WIRELESS-LAN] Large numbers of clients in one room Reducing transmit power should reduce the range devices can connect at particular data rates. You can remove support of some of the lower data rates so that as devices throttle down, they'll look for "better" APs more quickly instead of holding onto APs at 12, 9, 6mbps, etc. Keep in mind that it should be each channel, not AP/radio, that should be designed to support a particular number of devices. ========== Ryan Holland Network Engineer, Wireless CIO - Infrastructure The Ohio State University 614-292-9906 [email protected] On Aug 11, 2009, at 11:31 AM, Methven, Peter J wrote: Out of interest what level of transmission did you lower your APs to? I've found changing transmit power has very little effect within a single "open-plan" room, it only really seems to have much effect when the signal hits obstacles such as walls, and shelves of books etc. Many Thanks Peter Peter Methven. MBCS, BENG (Hons) Network Specialist Computer Centre (The Allen McTernan Building) Heriot-Watt University Edinburgh EH14 4AS Telephone: +44 (0)131 4513516 / 07774 427548 Email [email protected] -----Original Message----- From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:[email protected]] On Behalf Of Greg Gardner Sent: 11 August 2009 16:21 To: [email protected] Subject: Re: [WIRELESS-LAN] Large numbers of clients in one room Our team designed our system to accommodate large numbers of people in one area by installing a greater density of AP's, lowering the AP transmit power, turning off the slower B transmit rates, and encouraging users to utilize 5Ghz N. Thanks, Greg Gardner Manager, Network Communications Information and Technology Services Rochester Institute of Technology [email protected] -----Original Message----- From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:[email protected]] On Behalf Of John York Sent: Tuesday, August 11, 2009 11:05 AM To: [email protected] Subject: [WIRELESS-LAN] Large numbers of clients in one room Hi We have a small installation with about 40 Cisco lwap's (b/g) running on a Cisco 4402. I've just gotten a request from a group that wants to run 50+ clients in one room. The last time we tried that about 4 years ago, it was a disaster. We had fat AP's at the time. There were a lot of Mac's, and they kept grabbing each other instead of the AP's. Ugh. How do folks handle this now? With my current system can I just throw a couple more AP's in the room and let them have at it? Thanks John John York Blue Ridge Community College, VA ********** 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/. -- Heriot-Watt University is a Scottish charity registered under charity number SC000278. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. -- BEGIN-ANTISPAM-VOTING-LINKS ------------------------------------------------------ Teach CanIt if this mail (ID 921638077) is spam: Spam: https://antispam.osu.edu/b.php?c=s&i=921638077&m=171e5d494513 Not spam: https://antispam.osu.edu/b.php?c=n&i=921638077&m=171e5d494513 Forget vote: https://antispam.osu.edu/b.php?c=f&i=921638077&m=171e5d494513 ------------------------------------------------------ END-ANTISPAM-VOTING-LINKS ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. -- Heriot-Watt University is a Scottish charity registered under charity number SC000278. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
