Wireless LAN-multiple APs and/or Repeaters

rolion

Hello,

Working on a project...a building with two floors.
Each floor,in a square shape,needs wireless access for laptops.
Walls are concrete but almost top half off the inside wall is glass so penetration i don't think is going to be an issue..
Each floor gets 2-3 APs with PoE,TPLink brand ,3 antennas.
Definitively,i will not go for security,just for MAC address filter.Or,a basic wep changed every week ! Or only RADIUS if i get my head around !

Qs:
Do i have to set up same SSID for all APs or different,based on corner let's say N,E,W,S!?

Is it better to use one router as main or hub of WiFi network and then extend the WiFi with 2-3 repeaters acrosss the floor ?

Thanks in advance...

bhickey

It would depend on the size of the area and the maximum concurrent number of wireless users that you need to support.

Normally you'd use the same SSID but different channels (e.g. 1,6,11). This'll make life easier for people moving around the building. Then use one router as the DHCP server for everything and use each of the other AP/routers as an AP-only (i.e. in bridge mode with no routing/DHCP etc.). What model of TP-Link are you using for the AP's?

rolion

thanks for reply.

will be 10 users,using laptops with N standard.
area size,around 35m on each corridor,that will makes 4 x 35m length.

yeah,each AP will have same SSID but different channels per floor or top/bottom of the building..

TP-link TL-WA901ND with PoE switch from them as well.

thanks.

niallb

They're great APs - very flexible. I got a few a couple of weeks ago and have been well impressed. Good price too!

I agree totally with @bhickey. Use the same SSID if it's the same network.
Sorry about the length this grew to - I've been thinking about a similar scenario this morning, and it's a good excuse to write it up!

Do however use authentication and encryption. Set up even a PSK that gives access to the wireless network, and then make people authenticate before they use the connection if you can.
So long as you make the encryption settings identical on all APs, and you should prevent people having to type them in all the time.

There are two firewall CDs you can download called pfsense-2.0 or m0n0wall both of which have good features for controlling a wireless network - they allow for a Captive Portal, which you can control using Radius as you mention. They also allow you print out tokens to give access. These are single use keys you can print out as a spreadsheet and give to users. You can make batches valid for 10 years or 10 minutes, so can be handy to give temporary access of variable length. If you're registering MAC addresses anyway, you can have all your permanent equipment bypass the authentication requirement. These can be booted on an old PC if one is available, and also have good control over traffic shaping, which can be a major help if people are trying to use VoIP over wifi.

Main reason I replied here is to add weight to the channels recommended.
1,6,11 are not randomly chosen examples from those available.
They are the only three channels which do not overlap in terms of frequency,
and you will have far less interference if you build your wireless network
around those where possible

As a crude example with minimum hardware, try one AP on 6 in the center of the upper floor and one each on 1 and 11 on the edges of the lower floor.
If you need it then add one on perhaps 9 in the center of the lower floor, and maybe 5 and 2 on the edges upstairs.
Avoid channels above 11 if possible, or you'll find yourself with unexpected complaints from American visitors.
In your case mount the APs high to take best advantage of the glass walls.
The POE is handy, though the last TP-link I used had only 4 ports with POE.
Are you using the little power injectors they sometimes ship with APs for the others?


I'd suggest disabling DHCP on all of the routers, rather than trying to remember which is the master one which will bring down the whole system.
Either of the CDs mentioned above will also handle DHCP very neatly over a web interface, though of course you can use existing DHCP or simply use one of the routers - but mark it well.
Either give your APs static IP addresses, or make sure your DHCP server assigns them all the same address each time. A final suggestion is to choose IPs that reflect the channel they are tuned to, such as 10.0.0.1 10.0.0.6 10.0.0.11.

Be aware that there are some OS versions/card combinations - mostly older ones - that will lock on to a single AP for a given SSID. This is not a problem with your network,
and solving it for that one case will give all your other users too many headaches.
Unless the user with the older equipment will upgrade, explain the situation and suggest that they need to consider the wifi area as being smaller than everybody else or be prepared to make their device forget the network and reconnect if they go to a new desk.

Wherever possible, see can you run cables to people. The more users you can keep off the wireless network, the better the experience will be for everyone!

rolion

ok,thanks..now i have to get a cup(s) of coffee and digest your post !!

thanks...

lucernarian

A wee bit of the above information is incorrect. You can get 4 separate channels to work in Europe. 1, 5, 9 and 13 are all separate and do not overlap. Why use 3 separate channels when one can have 4...

The channels shouldn't overlap on the same floor if possible but it doesn't matter as much between floors as a thick concrete floor will limit any co-channel interference.

rolion

CCity ....made a big mess of this order ! they confirmed items in stock on tuesday,went to pay and collect...no more in stock !!! What a messy business !!!

So now i need to do the install with another APs,all work being planned for friday/saturday !
Any one,some experience with other brands please !?

bhickey

To_be_confirmed wrote: »

1, 5, 9 and 13 are all separate and do not overlap. Why use 3 separate channels when one can have 4...

There is some small overlap in a 1, 5, 9, 13 setup but more importantly, the wireless in some laptops will only see channels 1 to 11.

PogMoThoin

Just be aware that roaming like this will never be completely seamless. Some devices will give a signal level reading of the wrong ap, even though they're sending traffic through a nearer one with a higher signal. Some devices will also be stubborn and will need a disconnect and reconnect, I've two ap's in the house and a Windows 7 netbook here that won't roam even though a Ubuntu netbook and Android phone do it fine. Fixed situations will be fine.

I'd also run a cat5 cable to every desktop pc to save wireless for those that need it

An Apple TV or iPhone bought in the USA won't see channel 13

lucernarian

bhickey wrote: »

There is some small overlap in a 1, 5, 9, 13 setup but more importantly, the wireless in some laptops will only see channels 1 to 11.

That diagram is not quite accurate. If you take a look at the spectral mask from the 802.11 standard, "channel" 1 and 5 only overlap at a point where the power is -15dB from peak power density. That's quite a drop from two channels that properly overlap, like 1 and 4 for example. It wouldn't be an issue.

Not using channels 12 or 13 is an issue that primarily lie with manufacturer's drivers and firmware and I think that it's wrong to risk further network congestion for the sake of poor product development. There's nothing stopping american-only devices from using channels 1, 5 and 9 in any case.

rolion

PogMoThoin wrote: »

Just be aware that roaming like this will never be completely seamless. Some devices will give a signal level reading of the wrong ap, even though they're sending traffic through a nearer one with a higher signal. Some devices will also be stubborn and will need a disconnect and reconnect,

This kind of situation i'm tryin gto prevent it...and is very hard !
As laptops will be roaming along the building,there is noway that i can lock one laptop to one AP !

I've managed to get same AP from another supplier and the laptops are Toshiba.
I will play friday / saturday with some applications / settings that i can configure to evaluate the signal strength and connect to that AP,then based on the fact that one laptop will be in place for at least one hour,i can set some form of "TTL" to be locked to AP that laptop connected ,and then keep resetting it every hour,forcing the WiFi connection to re-establish itself !?? Kind of DHCP lease time ...
Also,maybe within RADIUS i can set something simillar !?

Let the fun begin...

PogMoThoin

Your best chance is with all identical ap's with identical settings. Try first with no encryption to make things simpler.

Fuzzy Clam

PogMoThoin wrote: »

Your best chance is with all identical ap's with identical settings. Try first with no encryption to make things simpler.

I would use a slightly different SSID for each AP to make it easier to id which one a PC is connecting to.

PogMoThoin

Fuzzy Clam wrote: »

I would use a slightly different SSID for each AP to make it easier to id which one a PC is connecting to.

That wouldn't be roaming then, which is what he's looking for. Devices will have an ap priority list, Windows has one and won't move to another ap as long as the one on the top of the list is in range no matter how weak the signal. The only way is to name each identically, with the same encryption and settings.

niallb

To_be_confirmed wrote: »

A wee bit of the above information is incorrect. You can get 4 separate channels to work in Europe. 1, 5, 9 and 13 are all separate and do not overlap. Why use 3 separate channels when one can have 4...

To save yourself or whoever has to deal with it sometime in the future trying to work out
why someone's laptop purchased in the US won't connect to parts of the network.
Like Spinal Tap, they go up to 11.

The AP is supposed to tell the client what Regulatory Domain it's in, and tell it it's OK to move to those channels,
but in practice it doesn't always work, and if you like to plan for eliminating potential intermittent problems,
this is too likely in my book to take place down the road.
If you use the 4 channels , write it up as a note on a label physically on the AP transmitting on 13. Someone might thank you some day!
If you don't need a 4th, it's just more convenient to leave out anything over 11 as mentioned above simply for American visitors.

lucernarian

In an office situation, using multiple APs on the one floor is as much for capacity as coverage. In those circumstances the Channel 1-11 devices won't lose out. Though yes I can see your point. In that case, perhaps channels 1, 5 and 9 can form the basis of APs situated for coverage everywhere, and in particularly busy areas a second AP on channel 13 can be used to supplement capacity. That should work successfully.

Laptops purchased in the US can still have adjustable settings for region through the wifi card's driver. Though annoyingly a variety of Atheros cards are provided with drivers that don't recognise Channels 12 and 13. I use Commview drivers that come with their commercial software for this purpose.

PogMoThoin

What about iPhones & Macs, good luck in getting drivers for those

rolion

Thanks to all for advise...i owe you a pint...wireless.ly !!

I've begin work today,ran CAT6 cables from the main switch to all APs across the building,one cable/link from switch all the way down to AP,just in case later i might want to use VLANs.
I used 1,6,11 as three APs will be enough for the shape of the coverage area needed.I reckon for forth i might need to change channel distribution.
All with PoEs in place,i have managed to get only one AP powered and tested.

With the settings "only N",from about 50 meters i've got 80% signal strength and 150m connection through walls ...that is really great !

i will use IPs for each as per channel number and same SSID...
looking at RADIUS over the weekend.

fingers crossed..
thanks