Sorry to folks who will see this twice, for some reason mail decided to send from a different account to where it arrived.
Hi Richard, When you say 500 per AP do you mean per physical unit installed? You need to make the distinction between “AP” and “radio” and later on “radio” and “channel” :) All the vendors are as bad as each other for coating their “number of users per AP” in a healthy layer of unicorns tears, it is a number made up by their marketing department based on theoretical limits, Cisco claim 400 per AP (200 per radio), Ruckus will claim 512 (256 per radio) etc. All of the claims are frankly BS and based on the maximum associations the radios will handle. This is how Xirrus get their “2k users per AP” number as they stuff 16 radios into a 35cm wide flying saucer and the chipset they use will do 128 clients max per radio. Out in the real world we take a conservative value that for casual use you can do 50 users per radio assuming decent hardware in a good RF environment / and assuming a proper design has been implemented. 5GHz is easier in that regard, 2.4GHz is dead to me. You can push the number of users higher but much further and you start to see a sharp drop in performance very quickly. Designing for high density wireless is all about getting the RF side of things right, and a good knowledge of 802.11 as a protocol is essential as making this stuff work in those kind of deployments is not an easy task (different vendors also have different nerd knobs and ways in which you can push this stuff to its limits). But really it does come down to RF design, at the end of the day you don’t run out rusty old bellwire and hope to pass Gigabit Ethernet over it, RF is WiFi’s layer 1. WRT to Xirrus I’ve seen their stuff fail more often than I've seen it working and I’ve certainly never seen a large Xirrus network that I felt couldn’t be done better with another vendors gear and discrete APs and directional antennas, there is a reason nobody else is taking that particular approach to building APs. As for vendors to suggest, well if I had to put my money where my mouth is I tend to stick to what I’ve used and what I’ve seen work and that would be Cisco, Aruba and possibly Ruckus. Cheers, Will >> On 9 Dec 2014, at 13:06, Charl Tintinger <[email protected]> wrote: >> >> Ive spent around 12 years rolling out various wireless systems around the >> world. The WIFI protocols do not lend themselves to high capacity access >> points. Even channel bonding, unless the air protocol is modified, this >> cannot be done. >> >> >> On Tue, Dec 9, 2014 at 11:37 AM, Peter Knapp <[email protected]> >> wrote: >> I spent quite a while on this with a couple of larger multi-vendor WAP >> distributors and they have clients of the big exhibition centres and music >> venues, and they use extremely steerable APs with shielding, much as you do >> with an audio line array if you are familiar, and don’t have anywhere near >> the number of users per AP you are citing. >> >> >> >> Since then we took on a football stadium and following their advice were >> deploying active densities in the order of half the numbers you are >> suggesting as the ACK time and in air RF interference / xtalk destroys >> throughput otherwise. >> >> >> >> Hope that helps.. >> >> >> >> Peter Knapp >> >> >> >> >> >> From: uknof [mailto:[email protected]] On Behalf Of Neil J. >> McRae >> Sent: 09 December 2014 11:31 >> To: Richard Savage >> Cc: [email protected] >> Subject: Re: [uknof] High Density Wifi >> >> >> >> I used their equipment as a $user rather than operator (couple of events) >> and was impressed - then had a bit of a play with the, I think, 6000 AP at >> MWC. Not deployed but on the shortlist to look at further - don't really see >> many folks taking this approach. >> >> >> On 9 Dec 2014, at 10:30, Richard Savage <[email protected]> wrote: >> >> Hi >> >> >> >> Im currently looking at some high density Wifi to support greater than 500 >> users per AP, probably looking in the region of 1 to 2 thousand per AP. >> >> >> >> Is there any manufactures that people have used before and would recommend? >> Have come across Xirrus and wondered what people thought of them? >> >> >> >> Many thanks >> >> >> >> Rich >> >> This e-mail is sent on behalf of Timico Partner Services Limited, a company >> registered in England and Wales, registered number 03128506, registered >> office Beacon Hill Park, Newark, Nottinghamshire, NG24 2TN and regulated by >> Ofcom. The information in this e-mail is confidential and is intended solely >> for the use of that individual or entity to which it is addressed. >> Unauthorised use, dissemination, distribution, publication or copying of >> this communication is strictly prohibited. If you receive this in error, >> please notify us by email to [email protected] and delete any copies. For >> information about how we process data and monitor communications please see >> our privacy statement. >> >> >
