12LEE

Hi All

I'm in the process of WLANning the house. I've found that inter-floor performance is really poor. Should I be surprised by this and run a cable up the house and just use WLAN for single floors?

Cheers

Lee.

IWatkins

I guess it all depends on the hardware and also how you house is made up. My access point (Netgear) is on the top floor (three floor house) at the back of the house and I still get 10Mb (indicated) in the front room (bottom floor, front of house). But the house is brick exterior with wooden joists, wooden floorboards throughout.

Performance starts to drop off halfway down the back garden (i.e. through a double thickness brick wall), and is down to 1Mb by the end of the garden (approx 130 feet from the access point).

Hope that helps

Cheers

Ian

12LEE

Interesting. I'm using two bridges, one at the back of the house middle floor (3 storey Victorian house - bricks, floorboards, etc) and one in the rear of the loft. Sometimes they ping fantastically, other times they timeout.

roadrunner

Lee - 802.11b WLAN maximum performance is approximately 6Mbps. With WEP enabled (recommended) you should expect around about a 50% performance hit reducing it down to 3Mbps. Now 3Mbps can only be achieved through direct line of sight within a distance of 1/2m radius. Taking into account that a WLAN network will work upto 50m indoors, the performance will range from 3Mbps (1/2m) too about 200K/sec (40m). Therefore IMO 802.11b WLAN is good enough to surf the Internet, access email etc.
To say performance is really poor is like saying how long is a piece of string – every environment is different. One thing I recommend is upon installation is to go through the various frequency channels to determine which one is best. You will be surprised on the speed difference, especially if your neighbour has a WLAN

If money is no object then look at 802.11a. This runs at a maximum performance of 20Mbps. At the end of the day, the best thing to do is to try it out

BTW – are you looking for a router/wireless combo or a standalone access point?

roadrunner

Lee - Didn't realise you already had some kit what type is it and what configuration are you running - WEP enabled etc etc

12LEE

Hi RR. I'm running a pair of Linksys WAP11 APs, each configured as multipoint bridges. WEP's off (for now). I'd describe performance as erratic, but mainly v.v.v.v.v.slow. I'll certainly try playing with all the channels.

roadrunner

Okay, forget WLANs for a minute. Imagine each channel as 5MHz. An AP needs 30MHz to work therefore 30/5 = 6 thus an AP needs 6 channels to operate in the airwaves. Now we will call a collection of 6 channels as a sphere. The sphere provides a performance of 6Mbps in a given wireless coverage area. If you place one AP in that sphere then that AP has the whole 6Mbps to use. But if you place a second AP in the same sphere then the two APs will fight (interference) over that 6Mbps. To stop them fighting you need to separate them. To do this you need to place the second AP into another sphere. So now we have two spheres with each APs having 6Mbps.
AP1 in Sphere 1 which use channels 1,2,3,4,5,6
AP2 in Sphere 2 which use channels 6,7,8,9,10,11
Next we need to physically connect the two APs for them to see each other. To do this both APs will have an Ethernet cable going back to the same hub.
So what we have now done is physically connected both AP. See below

AP1 in sphere 1
|
|
hub
|
|
AP2 in sphere 2

Finally all we have to do is program each AP to talk too each other using the same IP address range. The end result is you have a Wireless Local Area Network that allows nodes to communicate to each other.

Soz Lee, had to end the example short as I am going home. If you don’t understand the last bit then let me know
I will go through your setup tomorrow

rr

roadrunner

just about to go home and you reply

right, so you haven't got any wireless clients. All your PCs are on Ethernet. you are using Wireless as the connectivity between floors. Is that correct?

roadrunner

Lee, slightly confused here

Best way is this, for example
Top Floor
You have ethernet hub, 2 X wired PCs, 1 x Wired Ethernet Printer, 1 x AP
Communication between floors
Wireless or Ethnernet
Middle Floor
You have 1 x AP, 1 x Cable/DSL router with 4port, 3 x Wireless PCs
Communication between floors
Wireless or Ethernet?
Bottom Floor
2 x wired PCs, 1 X wired Ethernet Printer

12LEE

Timing eh?!

post 1: absolutely - I want to use wireless for communication twx floors.

post 2: sorry, being dumb, don't really understand?

Big thx for the help so far.

roadrunner

I get the picture now

Thought this was a basic home setup with wireless clients. Nearly mentioned that two APs was overkill for a home, glad I didn't now

Okay. You are on the right track. APs in Point-2-Point or Point-2-Multipoint mode, both APs should be on the same channel

Is the AP on the middle floor directly under the AP on the top floor?

Are you using any cordless phones, microwaves ovens nearby?

As mentioned a long time ago. Go though all the various channels from 1 to 14.

You got any TCP, throughput software to test? If not how will you be testing your performance?

12LEE

I'd say that they're seperated horizontally by ~5m and vertically by ~4m. One's next to an RF k/b&mouse receiver which I'll move and I think I'll experiment with all the channels per your suggestion.

Thx for the help.

Cheers

Lee.

roadrunner

Just did a quick search, some RF keyboards operate in the same spectrum (2.4GHz) as 802.11b If your does then it would kill your wireless connectivity

Good luck, let us know your outcome

rr

kryten

Using any videosenders? Some operate on the same frequency - I get a hit on performance and sparklies on the screen when I use both!!

roadrunner

Hi Lee

I think I know what your problem is. You are cutting your performance in half by running bridge mode plus you are most probably running both APs on the same channel.

Okay
For a start you shouldn't be running your AP in Bridge mode. They should be running in AP mode. Both AP should be connected you your wired network ie where every your ADSL router/switch is.
Bridge mode should only be used to connect two or more different WLAN together. Don't use bridge mode to connect another AP (Wirelessly) to your network... A big no no because your performance hit is substantial.
Secondly both your AP must be on a different frequency channel otherwise they will conflict with each other. Even though you have a selection of upto12 channels. In reality 802.11b can only provide 3 non-overlapping channels. Therefore only channels 1,7,13 are available. So choose channel 1 for upstairs and channel 7 or 13 for downstairs.
If possible reposition your AP’s towards the centre of each floor. Otherwise you are just wasting coverage space.
If you using a laptop then you must enable roaming on that card.

Lee if you describe your layout better, then I could help you more. where is your adsl point, do you want garden coverage, are they any particular rooms/floors you want the performance to be at its best etc etc

After you sort your performance issues out, I would recommend enabling WEP. It is a must!


[Edited by roadrunner - 6/10/2002 11:22:47 PM]

12LEE

I'll describe my app:

Middle floor - LAN 1:PC / Cable Modem
Top floor - LAN2: Standalone ethernet device, crossover cable to bridge/AP.
Bottom floor - future LAN 3 (and 4): each as LAN2

The standalone ethernet devices in LANs 2, 3 and 4 each need access to the PC in LAN1.

errr... that's it. Surely I'm bridging two LANs together over the air, therefore each AP (which can also be a bridge) needs to be configured as a point to multipoint bridge, rather than an AP, or am I misreading the manual?

I'm now confused about the channel! Aren't the bridges effectively on the same WLAN and therefore need the same channel settings?

Cheers

Lee.

[Edited by 12LEE - 6/10/2002 7:07:56 PM]

12LEE

Cheers RR - I get this, but that's not my app. I'm after:

ethernet client - xover cable - bridge to air

<air>

bridge to air - hub - LAN - server

<air>

ethernet client - xover cable - bridge to air

For arguments sake, let's say I have a PC on the middle floor and a printer (with an ethernet port) on the top and bottom floors and I want to be able to print from the middle floor to either floor using air, not cable, as the connectivity between floors. Possibly a confusing example!

Cheers

Lee.

(and to think that I used to be a Cisco rep and sold 250 buildings' worth of Cat6500 - no Aironet though!)

[Edited by 12LEE - 6/10/2002 8:57:14 PM]