High+bandwidth+DER+wireless

From: St. Margaret Mary's College Townsville


 * This page seeks to explain some technical aspects you need to get your head around to understand what wireless solution to buy. It also introduces a new enterprise player in the market with a superior solution (in our opinion)**

=
======

=
1:1 computing requires highly available, high throughput wireless access. Unless this is a guaranteed service supplied, 1:1 will soon be back in the days of 56 Kb/s modem speeds and more likely will make the adoption path by staff and students potentially fraught. If it doesn't just work...they can hardly be expected to just use it. At a recent conference at JPC in Brisbane, I experenced first-hand how good a decent enterprise level wireless deployment can be....and I have to say it was ordinary! In a situation where we would want to deliver speed to the client laptop, the solution JPC have is about as good as a busy home network. Not very impressive. Workable for sure...but not quality. We need to do much better than this. 802.11n is now ratified and adopted by vendors but of itself it has problems just as current WLAN access points have. The enemy is really radio noise! This is a problem that can only be addressed by having a wireless solution that is technical enough to get around this. Basically the problem is that the more APs you have to get you site covered, the more noise it creates and the less data throughput your clients experience. So how to get around this? Well you can... a) Spend $$ on a wireless survey that seeks to map out the best places to stick APs so that the place is covered but that dont' stomp on the other APs with noise by making sure (if possible) the APs are on a different channel. This in practice is almost impossible to do and wireless surveys IMHO are a waste of money to a large extent. b) Buy horrendously expensive gear where the APs are centrally managed by a "switch" and are dynamically managed to try to ramp down the wireless volume when the are causing too much noise for others. 3Com etc have such solutions. Such systems do their best to ensure data packets make it to the client but there are some downfalls. "roaming" is not entirely seemless. WIndows clients tend to hop from AP to AP whenever they feel like it. This can cause lags which to the user look a lot like lower throughput. c) Buy gear that uses Atheros chipsets (and hopefully the client wirelesses too). These radios have "adaptive noise immunity" technology. They do what the 3Com stuff does but for a fraction of the price. SMMC has such a system currently and it works well. Channel "bleeding" noise is not that much of an issue but is not "switch" managed centrally except there is an SNMP based management tool called the "Dude" that is pretty cool. We believe in fact this gear (Mikrotik/RouterOS) can do the fancy "switch" trick. d) Look at a new technology that is different again by Extricom [] This gear is like the 3Com centrally managed gear but...======
 * Uses single channel saturation technology. ie you can have all the APs on the one channel and not lose throughput!
 * The number of APs you can install is limited by your wallets only.The availablity increases and throughput doesn't drop.
 * a/b/g/n/ + 100/1000 aps and switches mean late model netbooks get huge bandwidth but without the "n" saturation problems.
 * True seemless roaming where all packets are guaranteed to make it to destination routed correctly via the AP it needs to now go through!

St Margaret Mary's College will be trialling this gear this year if possible.

At the DER meeting 3Com were discussed IIRC and others too. There was talk of leveraging bulk dealing etc. There are new developments in the technology we will need. In order to understand what solution to go for it is really necessary to have a pretty deep understanding of how data wireless actually works. I hope this helps a little.

Keith Spencer St Margaret Mary's College Townsville