[MLB-WIRELESS] OpenWRT long distance utility

[vak]

That is an AWESOME improvement!!!

Ratbaggy wrote:

>Hi Dan and All,
>
>I am pleased to report that the utility works very well indeed.  I've
>experimented on our 14 km link between Blackburn North and Kangaroo Ground
>(ILW to HKG) and the throughput (doing a http download) has gone from around
>60 KBytes/S to......
>
>Now wait for it..........
>
>Excuse me for getting a little excited........
>
>1130 KILOBYTES PER SECOND!!!!!!!!!!!!!!
>
>There are WRT54G Ver 2's running on each end with Freifunk version 1.1.4
>firmware.  Antennas are 24 dB Hills grid and 19 dB Panel.
>
>This link doesn't have a great path and the line of sight skims across the
>roofs at the Blackburn end and the signal strength as reported on the crappy
>WRT radios is -77 dBm with noise at -94.
>
>My recommendation with setting the "distance" for dctrl is to start at
>double the distance and reduce the number to the point where throughput
>reaches a maximum.  Shortly beyond this point the throughput will drop
>drastically.  In our case with the 14 k link the optimum speed was achieved
>with the parameter set to about 21000 but we backed it off to 22000.  I
>suspect the programmer may not have made allowance for the round trip delay.
>
>Due to the poor signal to noise ratio on our link optimum performance was
>achieved with the radios locked to 18 Megabits per second, any faster or
>slower and the performance dropped off.  With another 10 dB of signal to
>noise I suspect some further gains may be possible although at this point
>the router may run out of steam before the radios.
>
>The settings that were used:
>
>WLAN Mode: Ad Hoc
>Radio Mode: G Mode Performance (whatever that means)
>Transmission Rate: 18 MBits/S
>CTS Protection: Disabled
>Frame Burst: Enabled
>/usr/sbin/dctrl 22000
>
>For other links with different S/N and distances Transmission Rate and dctrl
>will need to be optimised.  Hopefully some others can do some more
>experimenting on different links.
>
>Dave.
>
>----- Original Message ----- 
>From: "Dan Flett" <conhoolio at hotmail.com>
>To: <melbwireless at wireless.org.au>
>Sent: Monday, February 20, 2006 8:24 PM
>Subject: [MLB-WIRELESS] OpenWRT long distance utility
>
>
>  
>
>>Hi all,
>>
>>I've found a few links regarding a utility for OpenWRT/broadloom-based
>>routers.
>>
>>The utility is called dctrl and it works quite simply - you just put in
>>    
>>
>the
>  
>
>>distance of the link as a parameter and it tweaks the broadcom radio
>>    
>>
>timing
>  
>
>>settings to be optimal for that distance.
>>
>>You can get it here:
>>http://openwrt.inf.fh-brs.de/~nbd/dctrl.
>>
>>Further discussion of link tests here:
>>http://forum.bsr-clan.de/viewtopic.php?p=10530.
>>http://forum.openwrt.org/viewtopic.php?id=4447
>>http://forum.openwrt.org/viewtopic.php?pid=21034
>>
>>I'd be keen to hear if people with WRT-based long-distance links have any
>>success with this.
>>
>>Regards,
>>
>>Dan Flett
>>Secretary
>>Melbourne Wireless
>>_______________________________________________
>>Melbwireless mailing list
>>Melbwireless at wireless.org.au
>>http://wireless.org.au/mailman/listinfo/melbwireless
>>
>>
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>>    
>>
>17/02/2006
>  
>
>>    
>>
>
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