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wakeadmin
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Best setting for wireless range?

Sun Dec 30, 2007 8:00 am

I have the RB133 and an XR2 connected to a 15dbi omni and am trying to have 6 small single story houses, all within a 100 yard circle, covered (interior). I just dont seem to be getting the distance I would expect. Can someone give me the best setting for output etc to get the best range? I don't care about throughput that much, so 802.11b (11mb/s) settings would be acceptable. I would also appreciate some info on making sure I am getting the full 600mw out of the card. I am not in the states and don't have to worry about any max power output regulations. Also, can the rb133 show the current output of the xr2? I have see other boards that query the card to show the current status.

Right now I am using armenia as the country, and have the antenna db set to 0 and have manual tx power set to all rates fixed at 23 dbm

Thanks, John
 
jcremin
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Re: Best setting for wireless range?

Sun Dec 30, 2007 8:11 am

If you manually have it set to 23dbm you are driving it way too hard and just sending out distortion instead of clean signal and might have already damaged the card. Leave it at default and it will run at full power for the rate it connects at.

Use this table for the power offset if you must set it manually: http://ubnt.com/downloads/SRXR_power_offset.pdf

As you can see, the max you should ever set it at is 18, which actually outputs 28dbm (the max output of the card). Setting it to 23 is trying to push it up to 33, which is way more than it's designed to do.
 
wakeadmin
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Re: Best setting for wireless range?

Sun Dec 30, 2007 11:09 am

Thanks for the info. I backed them back down to 17. I was playing with different settings while trying to get a descent range and started out at 17. I just can't believe I can't get a range of 200 feet going through one wall.

Any other suggestions?
 
alex_rhys-hurn
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Re: Best setting for wireless range?

Sun Dec 30, 2007 1:54 pm

There could be other things going on here.

Really take some time ot have a look at the position of the antenna relative to the houses. Remember that the high gain omni will have relatively little downtilt so you dont want to mount it too high.

Also check the quality / condition of your antenna cables and pigtails. In the past this has proven to be a common problem area, with faults due to too much cable bending resulted in broken conductor inside to faulty connectors and moisture getting in.

A simple way to check these is to get your laptop running with netstumbler running and measure the strengths you get from the 15dbi and then get a standard 2dbi omni as you might find bundled with a home router, and see if there is any change in the strengths / quality.

I dont know where you live but in my country it is common for buildings to have metal roofs, and this plays havic with wifi signal. Another reason not to mount antenna too high.

Also in my country it is common to have serious steel bars across the windows for security pruposes, and I have had trouble with this causing signal strength problems too.
 
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Re: Best setting for wireless range?

Sun Dec 30, 2007 9:04 pm

Is your ap outside or inside ?
how far is the wall from your AP?
normally the range will depend on
1.material the wall is made of.
2.the position of your setup.
3. interference from other network.
with 2.4 in mind.
 
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Re: Best setting for wireless range?

Sun Dec 30, 2007 11:21 pm

You may have foil insulation in the residences which will stop the wireless.

15db antenna with 600mw should be good for about 15 miles. You could probably use 50mw and an 8db omni and things would be working better.
 
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Re: Best setting for wireless range?

Sun Dec 30, 2007 11:25 pm

I agree with JP.

First, ditch the XR2 - you probably already damaged it by tweaking the power settings.

Get yourself a SR2 or CM9 and a 8dbi omni antenna. Spend the extra money and get a good jumper - Andrews preferably.
 
wakeadmin
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Re: Best setting for wireless range?

Mon Dec 31, 2007 12:45 am

Thanks for the info.

I ran the card at 20 for approx 2 hours and am now back at 17. I still have the same range as before, and I get the same range with 4 different AP's 3 of which never had the power setting tweaked, so I don't think the card is damaged. I have 2 different antennas, a 15db and a 12db, both with a 3deg downtilt. I haven't been able to see any difference in range with the 2. I have experimented with many different mounting locations. I have tried approx 50 feet high, to only 10 feet and get varying degrees of coverage, but none that seem correct. I use netstumbler to check the areas and get in the mid 70's for signal inside a house with one wall separating, approx 100 feet away. The houses are older construction and have wood and shingle roofs. The walls vary in construction but are mainly stucko and sheetrock. The AP's are mounted outside. After having one AP mounted to the antenna with an approx 4 foot cable, I have all the others mounted directly to the pigtail on the box. I have several 9dbi omni rubber duck antennas coming to try to see if the narrow beam of the 15 and 12 is the problem. I tried a 7db rubber duck off of a linksys and saw little difference. I did however have to rig an adapter to make it fit. There is practically no other radio in the area in the wireless range. I use Wispy and see no interference.

Any other suggestions?
 
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Re: Best setting for wireless range?

Mon Dec 31, 2007 2:12 am

What are you using for the client side?
 
wakeadmin
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Re: Best setting for wireless range?

Mon Dec 31, 2007 3:12 am

99% of our users will be using laptops with built in wifi. Some will have external usb adapters. I am guessing those will get better reception, but I am testing with a fairly new sony Vaio with built in b/g.
 
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Re: Best setting for wireless range?

Mon Dec 31, 2007 3:37 am

Whats the noise floor?
 
wakeadmin
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Re: Best setting for wireless range?

Mon Dec 31, 2007 6:30 am

Reported by the ap it shows 0, in Netstumbler it shows -100 under the noise heading.
 
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Re: Best setting for wireless range?

Mon Dec 31, 2007 6:39 am

Reported by the ap it shows 0
Something isn't right there...

If you do a scan how many other AP's do you pick up?

Have you tried changing the Antenna Mode under the advanced tab?

Post your entire wireless configuration for me.
 
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Re: Best setting for wireless range?

Mon Dec 31, 2007 6:42 am

You'll get a widely varying success with laptops trying to connect. Most of them have crappy antennas and even crappier wireless cards. The big problem is that even if the laptop can see the AP, it's transmit power is too low to get the signal back to the tower. The USB ones will help, but in my experience, I usually have to mount a small panel antenna (usually like 13dbi) at the client side and let them plug it into their own AP for their personal use inside the house.
 
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Re: Best setting for wireless range?

Sat Jan 05, 2008 7:11 pm

I can't remember - does the XR2 have Antenna A and Antenna B setting??? (we've changed everything to R52H's)

Another thing - try using a 8 or 9 dBi Omni instead...

Regards
 
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Re: Best setting for wireless range?

Sat Jan 05, 2008 8:42 pm

You may have foil insulation in the residences which will stop the wireless.

15db antenna with 600mw should be good for about 15 miles. You could probably use 50mw and an 8db omni and things would be working better.

JP's right on.. your gain is WAY too high on the omni.. the verticle beamwidth is probably very narrow... the higher in gain the smaller your beamwidth gets.. Try a much smaller omni 5-8dbi and you'll get better results.

The other thing you have to consider is the TX power of the receiving device. Most laptops have a ~65mW wireless card, sometimes less. The card may be able to receive the signal very well, but its ability to be heard by the AP is unlikely due to the low transmit power.

Then you have other environmental variables to consider as well (ie: construction of buildings, antenna height and placement, trees or any other obstacles intruding on LOS). At the distances you're talking these are probably less of an issue.

You may end up needing multiple low powered AP's in a mesh type configuration depending on the environment, size of the coverage area, and power of the receiving device.

Power isn't everything! You could probably make this work with a 2-3 rb133's coupled with r52's and low gain omnis (5dB).
William Burnett
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wakeadmin
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Re: Best setting for wireless range?

Mon Jan 07, 2008 11:27 am

Thanks for all the tips. I now have 1 ap with a 9db rubber duck omni on the second floor of each building and 2 ap's outside on the roofs with a 12 and a 15 db antenna. We still have some apt's that have low signal but I think everyone can connect now. We are thinking about the personal ap in the rooms that don't have a great signal, but I am not sure about the mac filtering setup. If we authorize their ap, (such as a Linksys running the wireless in client mode) won't anyone be able to connect to the ethernet ports and not have to be authenticated by our main ap?
 
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Re: Best setting for wireless range?

Mon Jan 07, 2008 4:43 pm

I often use an inexpensive access point in locations where signal is poor in wireless client mode (because they are cheaper and easier to get in my country than mikrotik). There are a few gotcha's that I have come across to watch out for.

1: Many linksys AP's only connect in wireless client mode to ANOTHER linksys ap OF THE SAME MODEL
2: If you want to do this stick with D-Link 2100ap or level one as they will connect happily to Mikrotiks in client mode.
3: When you put an AP of these types in client mode they will then pass the MAC address of the computer connected to it via cable, and so therefore you cannot have more than 1 computer connected say via switch, you must put a router......

So, whilst it is tempting to use an inexpensive device in those apartments there are some things to watch out for, but if you do this with mikrotik gear you dont have these issues. ANOTHER reason to use mikrotik.

Anyway. Its up to you....
 
wakeadmin
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Re: Best setting for wireless range?

Tue Jan 08, 2008 4:23 am

Thanks for the info Alex. Those were issues I was afraid would come up. I guess the best bet is to go with a 2nd wireless card in the ap and run an antenna to the other floor. Or just go with another complete ap and connect via cat 5. I would do that with the Linksys, but having to manage the mac filtering on the Linksys separately than the Mikrotik would be a real pain.

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