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rviteri
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RB751u-2HnD wireless disconnects

Tue Feb 21, 2012 7:35 am

Hello all,

I got an RB751u-2HnD to use as a home router. I have small apartment and everytime I move to the other room (thats about 7 meters away) I randomly get disconnected. The power output of the router is in default (its supposed to be a 1W power output which should be enough).

Can someone please advise?

The band is 2GHz-n, and my current (I am at the other room) CCQ is about 18-20%, with a noise floor of -99 dBm.

Also my ping spikes from 1ms (when I am in close) to 600 ms (in the other room).

Can someone please advise?
 
ranpha
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Re: RB751u-2HnD wireless disconnects

Tue Feb 21, 2012 9:01 am

Used to be the same problem I have. The wireless performance of this routerboard is simply poor without an external antenna. Pinging the router over wireless and you can get 4-digit ms latency.

What I have done is to put the router in an open small book rack, cover 2 sides of the inner wall of the book rack with aluminum foil, then put the end of the router where the internal antenna is located at the corner where the aluminum foil is applied. Now the CCQ vastly improves at >90%.
before.jpg
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RB751u-2HnD wireless disconnects

Tue Feb 21, 2012 11:16 am

If you are in an apartment what other 2.4 ghz ap's are running nearby ?

Use wireless snooper to help choose a channel.

Also sometimes lower power is better.

Perhaps changing channel will help.

Also be sure under HTm both chains are enabled.

I am getting pretty reliable access in a 100m2 building as well as good coverage outside for about 20+ meters.
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rviteri
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Re: RB751u-2HnD wireless disconnects

Tue Feb 21, 2012 11:17 am

Thanks for the input. Do you have a pic of your creation?
 
rviteri
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Re: RB751u-2HnD wireless disconnects

Tue Feb 21, 2012 11:20 am

If you are in an apartment what other 2.4 ghz ap's are running nearby ?

Use wireless snooper to help choose a channel.

Also sometimes lower power is better.

Perhaps changing channel will help.

Also be sure under HTm both chains are enabled.

I am getting pretty reliable access in a 100m2 building as well as good coverage outside for about 20+ meters.

Which antenna mode should I have? A, B or rx-a/b
 
rviteri
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Re: RB751u-2HnD wireless disconnects

Tue Feb 21, 2012 11:25 am

Anyone knows of any external antennas with an MMCX connector?
 
ranpha
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Re: RB751u-2HnD wireless disconnects

Tue Feb 21, 2012 1:29 pm

I cannot take pictures until tomorrow at least. MMCX antenna are rare, unlike RP-SMA.
 
ranpha
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Re: RB751u-2HnD wireless disconnects

Sat Feb 25, 2012 4:32 am

Sorry for the very late reply. Only on the weekends I managed to get to take a few pictures. The quality isn't good because I'm using camera phone.
DSC00229v2.jpg
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rviteri
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Re: RB751u-2HnD wireless disconnects

Fri Mar 02, 2012 2:47 am

Great pics man! I did a windsurfer once!
 
vik1988
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Re: RB751u-2HnD wireless disconnects

Fri Mar 02, 2012 4:17 am

If you are in an apartment what other 2.4 ghz ap's are running nearby ?

Use wireless snooper to help choose a channel.

Also sometimes lower power is better.

Perhaps changing channel will help.

Also be sure under HTm both chains are enabled.

I am getting pretty reliable access in a 100m2 building as well as good coverage outside for about 20+ meters.

Which antenna mode should I have? A, B or rx-a/b

Hi, if you are using external antenna then you have to change Antenna mode B, If external antenna not available you can use HT Chains 0,1 in both tx and rx.
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rviteri
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Re: RB751u-2HnD wireless disconnects

Fri Mar 02, 2012 6:54 am

I can't find an antenna with the MMCX connector
 
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Re: RB751u-2HnD wireless disconnects

Fri Mar 02, 2012 8:21 am

No answer to your question? How to write posts
 
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Re: RB751u-2HnD wireless disconnects

Fri Mar 02, 2012 6:09 pm

ranpha, what speeds do you get, say copying a file from a file server to a notebook at 2.4GHz 20Mhz width?
Like this: Server --LAN-->RB751U-2HnD--WiFi-->Notebook/PC

The best I can manage is about 30mbps without encryption and 25mbps with WPA2-AES.
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ranpha
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Re: RB751u-2HnD wireless disconnects

Sat Mar 03, 2012 1:21 am

I do not have any devices connected to the router via Ethernet except the modem, so I cannot really say. All computers and phones here connect to the router wirelessly. Copying a file from a laptop to my desktop computer wholly via wireless tops out at about 16 - 17Mb/s only though, the computer only has a 150Mbps maximum speed.

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