Multiple Wireless clients bandwidth

[renegade]

Is there any system available that will allow wireless clients to connect to it and allow the full bandwith for each client, rather than sharing the bandwidth between them all.

 

We have quite a lot of overhead at logon and the school are wanting to connect around 120 clients wirelessly, so if they all have to share 54mbits between them it's gonna be a nightmare!!

 

Any solutions?

[Geoff]

Currently, no.

[broc]

Multiple access points equals multiple 54mbit connections, but then you have to cope with load balancing & RF interference. Rule of thumb is 1 AP to every 15 devices......

[dhicks]

Is there any system available that will allow wireless clients to connect to it and allow the full bandwith for each client, rather than sharing the bandwidth between them all.

 

Nope, wireless bandwidth is inherently a shared medium (unless you have some system of tightly-focused beams of some kind).

 

We have quite a lot of overhead at logon and the school are wanting to connect around 120 clients wirelessly, so if they all have to share 54mbits between them it's gonna be a nightmare!!

 

Yep. You can go and buy a fancy managed wireless solution, that'll probably increase performance a fair bit, but will set you back £10,000 - £30,000+. You could try and isolate 3 access points (each set to a different channel) in each classroom by constructing some kind of Faraday cage around each classroom (I'm thinking metal-filing "magnetic" paint)...

 

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David Hicks

[Geoff]

I'm thinking metal-filing "magnetic" paint

 

Lead paint works great for this, had some portacabins coated in the stuff a while back, no wifi, no mobiles, no FM radio...

[SimpleSi]

Rule of thumb is 1 AP to every 15 devices......

 

..thats with the wind behind you

 

regards

 

Simon

[wesleyw]

When the N standard is finally ratified this will be the case. But at present ABG don't.

[dhicks]

Is there any system available that will allow wireless clients to connect to it and allow the full bandwith for each client, rather than sharing the bandwidth between them all.

 

When the N standard is finally ratified this will be the case.

 

How does that work? Shurely there's only so much wireless bandwidth available in a given section of physical space?

 

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David Hicks

[Geoff]

It works by aggregation in the MAC, and no it doesn't eliminate the problem. Merely providing a 30% improvement over current implementations.

[contink]

Having read a lot about this and understanding about 30% of it ... am I right in assuming that you can setup a system that uses band A for one set of clients and the remainder (b,g,n) as another... Obviously you need AP's that can handle both or both types of AP but that's one possible way to go...

 

But still, even then you're sharing your bandwidth.

[spc-rocket]

The problem with wireless is the half-duplex issue, until they can sort this out it will be difficult have many stations connected to the AP and all of them working and having enough bandwidth.

 

Managed wireless is the way to go as it certainly helps in sorting out the channel issues as well as only allowing x number of devices to an AP. If i were looking for any managed wireless controller or APs be sure that it support the future N standard via firmware or other methods because it will be a big thing for wireless and will allow better bandwidth with MIMO (Multiple IN,Multiple Out) technology.

 

Ash.

[dhicks]

Having read a lot about this and understanding about 30% of it ... am I right in assuming that you can setup a system that uses band A for one set of clients and the remainder (b,g,n) as another...

 

You mean as in a couple of laptops use 802.11a networking, a couple use 802.11g, etc? Nope, that would make things really slow! All these protocols work in the same range of frequencies - around 2.4Ghz. This is because this chunk of the radio spectrum is available for unlicensed devices to use freely - transmit on any other frequency and you need a license. The different protocols are improvements on each other - 802.11n is simply the latest way people have figured out of stuffing as much data into the wireless bandwidth available.

 

The chunk of bandwidth available to wireless devices can be split up into 11 (or sometimes 13, depending on the country you're in and local radio licensing laws) channels. Even these aren't really discreet, they're so close together they will still cause interference with each other.

 

For the non-technical explanation, you can only fit so much data into one part of the electromagnetic spectrum. The next time the head phones your office asking if you can get more speed out of the wireless routers, you're perfectly justified to point out that they are going as fast as they can - you canne' change the laws of physics.

 

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David Hicks

[Chris_Jones]

Actually 802.11a uses the 5Ghz part of the spectrum, its 802.11b and g that use the 2.4Ghz.

 

If you split devices half and half on A and G bands that effectively gives you double the bandwidth. The one to avoid is having B and G devices on the same network, as everything then runs at a max of 11Mbps rather than 54 - so you have 1/5th the Bandwith shared between all the clients.

[Geoff]

802.11n uses both the 5Ghz and 2.4Ghz spectrum, so when 802.11n devices become widespread your little 'trick' wont work any more.