Wireless network : Potential plan and making HT listen

[contink]

This is something of a call for assistance in making a feasible and realistic plan for a primary school which has no choice but to use laptop trolleys for it's IT provision but I think needs to tweak the specification somewhat to avoid overwhelming the infrastructure (which also needs upgrading).

 

In a nutshell this school has 12 classrooms (of which around 4 are early years) and wants to put in around 3-4 laptops in each classroom as well as having two laptop trolleys with approximately 15 laptops on each.

 

The ICT co-ordinator is looking to pretty much ditch existing workstations and work purely from laptops, using the wired network only via docking stations within the school thus putting an enormous pressure on a wireless network with around 80-90 laptops potentially using the system at once. More realistically I'd expect a worst case scenario of around 25 laptops in a single area but even so that's quite a load for one or even two local access points.

 

My question or questions is/are really this..

 

How best to reduce the stress on the infrastructure and what infrastructure to provide to best meet the overall needs of the school.

 

To date my rational is more or less the following:

• Retain the workstations (or replace them) so that at least one machine per classroom is using the wired network (not the wireless)
  
• Strongly recommend the use of a docking station for the main smartboard laptop, again using the wired network where possible.
  
• Reduce the number of laptops on the trolley to 13 rather than 15 so that there's at least one laptop per 2 children in class (class sizes of 30-34) with the other units already in the classroom being utilised too.
  
• Definitely use a managed wireless system
  
• Consider putting in 11a Access points for the classroom machines to access and 11b/g AP's to handle the laptop trolleys
  
• Try to impliment a booking system so trolley usage does not to coincide with class neighbours.

 

Anything I'm missing here?

[dhicks]

Consider putting in 11a Access points for the classroom machines to access and 11b/g AP's to handle the laptop trolleys

 

If you're buying new laptops and wireless equipment anyway you might as well get wireless-N capable laptops and compatible access points, which will make full use of the bandwidth used by both 802.11a and 802.11g. Seemingly Apple laptops are wireless-N capable, must be others out there.

 

--

David Hicks

[localzuk]

I would take a look at the BECTA guidelines on the issue. If I recall correctly, they advise schools to only use wireless in addition to a wired network.

 

The main thing out of all this is that you are going to have 25 laptops or so in an area connecting at once. This means you will want at least 2 or 3 access points to cover said areas via a managed wireless system. I would suggest that your first port of call should be getting out some wireless network specialists to do surveys and advise as to what they think. This will allow you to build around such infrastructure.

[torledo]

This is something of a call for assistance in making a feasible and realistic plan for a primary school which has no choice but to use laptop trolleys for it's IT provision but I think needs to tweak the specification somewhat to avoid overwhelming the infrastructure (which also needs upgrading).

 

In a nutshell this school has 12 classrooms (of which around 4 are early years) and wants to put in around 3-4 laptops in each classroom as well as having two laptop trolleys with approximately 15 laptops on each.

 

The ICT co-ordinator is looking to pretty much ditch existing workstations and work purely from laptops, using the wired network only via docking stations within the school thus putting an enormous pressure on a wireless network with around 80-90 laptops potentially using the system at once. More realistically I'd expect a worst case scenario of around 25 laptops in a single area but even so that's quite a load for one or even two local access points.

 

My question or questions is/are really this..

 

How best to reduce the stress on the infrastructure and what infrastructure to provide to best meet the overall needs of the school.

 

To date my rational is more or less the following:

• Retain the workstations (or replace them) so that at least one machine per classroom is using the wired network (not the wireless)
  
• Strongly recommend the use of a docking station for the main smartboard laptop, again using the wired network where possible.
  
• Reduce the number of laptops on the trolley to 13 rather than 15 so that there's at least one laptop per 2 children in class (class sizes of 30-34) with the other units already in the classroom being utilised too.
  
• Definitely use a managed wireless system
  
• Consider putting in 11a Access points for the classroom machines to access and 11b/g AP's to handle the laptop trolleys
  
• Try to impliment a booking system so trolley usage does not to coincide with class neighbours.

 

Anything I'm missing here?

 

With such a potentially large number of laptops connecting to the wifi network at the same time load balancing of clients between access points is an absolute must....another thing that may be of advantage is specifying AP's with dual radios and then associating cients with the individual radios to improve throughout for each client.......802.11a is criminally underused in enteprise WLANs surprising as it's so effective in areas of potential interference from dec phones, microwave owens and the like.

 

Agree that you should look at draft-n........as it stands it gives you more bang for buck, but with either a/g or n such a high density of wireless users could reduce things to a crawl without careful planning.....

 

Never liked the idea of wifi replacing the wired network - as that sounds like what you're trying to do. Wifi should be a complimentary technology filling the gaps in the enteprise, with certani caveats, that the wired network can't reach AND providing mobility when required NOT mobility all of the time. wifi as a replacement technology for wired ethernet makes me uneasy. All that work gone into eliminating shared networks and creating dedicated microsegmentation in network switches and now we're returning to a shared medium model because we don't like wires.

 

Don't get me wrong, i luv wifi, have had a lot of fun implementing it, but even draft-n is not the magic bullet for our connectivity woes.

 

 

fortunately with a managed system you can setup load balancing with ease

[Oops_my_bad]

bearing in mind 80211n hasnt even been ratified yet - is it worth the risk the OP looking into?

[contink]

bearing in mind 80211n hasnt even been ratified yet - is it worth the risk the OP looking into?

 

If (and it's a big "if") I look at 802.11n capable AP's they will be ones that can be firmware upgradeable. As to the laptops themselves the situation will be dependent on whether they want the number they do and the balance between budget and life expectancy.

 

As for wireless vs' wired... trust me this is not a decision there is any way around. There is a room wired for use as a computer lab but the situation is space is so lacking that even the designated staff room was taken as a classroom and the chance of the lab being available as such is just not viable until the roll numbers fall. So it's a rock and a hard place. I'm just trying to do the best I can with the resources we have to hand.

 

At least the good news is that there's a realistic budget involved so it's not all bad..

[torledo]

bearing in mind 80211n hasnt even been ratified yet - is it worth the risk the OP looking into?

 

i would say 11n is ready for the enteprise - especially as even cisco got tired of waiting for ratification and recently released 11n products....

 

ratification has been unnecessarily delayed too many times - it's become this long, drawn out process that hasn't done anyone any favours. i don't see any real reason not to implement 11n and i don't personally see it as a risk. during the whole pre-n / draft-n stage it was really about the vendors working to make compatible products and setting the agenda with actual product development and release....instead of standing around with their hands in their pockets waiting for a standard - and all credit to them. Cisco were willing to stand around and assume an ultra-cautious position and it was only until the world and has wife had started using draft-n that they decided they had to dip their toe in........(normaly cisco is sooo late to a party that they enter the market via a acquistion or two just to avoid playing catchup - but not necessary this time.)

 

if draft-n is good enough for the two elephants in the wifi room - intel and cisco - it's good enough for business.

[petectid]

Consider putting in 11a Access points for the classroom machines

 

If there are only single machines in each classroom connecting to the 802.11a APs, dependent on the design of the building and its structure, are you not concerned that quite a few of these would need to be deployed. As the signal in 802.11a is one of the poorest for penetrating structures and obstacles?

[contink]

If there are only single machines in each classroom connecting to the 802.11a APs, dependent on the design of the building and its structure, are you not concerned that quite a few of these would need to be deployed. As the signal in 802.11a is one of the poorest for penetrating structures and obstacles?

 

Excellent point... The school is a relatively new build so I'm not dealing with solid stone partitions but still, I would need to test the 11a range.

 

Just to note as well that we're talking roughly 3 or 4 classroom machines per classroom so if I could handle those through the 11a band (range restrictions withstanding) then that would obviously take a weight off.