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-   -   Linksys WRT54gs v5 (http://cellar.org/showthread.php?t=11660)

Elspode 09-05-2006 07:23 PM

Linksys WRT54gs v5
 
So...when we got the laptop awhile back, we also snagged a Linksys wireless router from Sams at the same time. Did I know that some were tremendously more desireable than others? I did not. But now that I have it in service, and have spent some time trying to improve its performance without spending money, I find that I should have checked it out first.

It seems that the WRT series of Linksys wireless G routers were made with 8 megs of flashable ROM and a *Linux operating system*. Why is this cool? Because the Open Source crowd has created hacked operating systems that let you do neat things with them...the neatest being that you can *increase the output power* of these things.

I need to increase the output power on mine, because I am getting terribly marginal signal in my kid's apartment across the driveway, and I can't spend $100 on a bridge or other nifty signal gizmo right now. However, beginning with v5 of these boxes, Linksys cut the ROM down to 2 megs and changed the OS to VxWorks, effectively making it no longer possible to hack these boxes and subvert them to your whims. Bastards.

There is an alleged method to install a stripped down version of one of the most popular of such firmwares, but despite having followed the instructions implicitly, I was unable to do it. So...any of you out there enough of a computer geek to give me any ideas, here?

To let you know how desparate I am, today, I took the little coax-connected remote antenna on my kid's 'net card and stuck it into a coffee can through a hole in the bottom at a calculated position, making a "cantenna".

It improved the s/n by 100%...

glatt 09-05-2006 07:34 PM

Quote:

Originally Posted by Elspode
To let you know how desparate I am, today, I took the little coax-connected remote antenna on my kid's 'net card and stuck it into a coffee can through a hole in the bottom at a calculated position, making a "cantenna".

It improved the s/n by 100%...

That's awesome! If the corporations won't provide what you need, you make it yourself.

mbpark 09-05-2006 08:34 PM

Get this firmware then...
 
I had this router, and used this firmware with it:

http://www.dd-wrt.com/dd-wrtv2/index.php

This is an excellent router when you reflash it the right way :)

Mitch

Sperlock 09-05-2006 08:37 PM

Is there anyway you can tell what version it is from the box, barcode, whatever without opening it?

Elspode 09-05-2006 09:59 PM

Quote:

Originally Posted by mbpark
I had this router, and used this firmware with it:

http://www.dd-wrt.com/dd-wrtv2/index.php

This is an excellent router when you reflash it the right way :)

Mitch

I did try the micro version of dd wrt, following some rather detailed instructions to the letter. The router refused the binary that you are supposed to load first.

There are several versions of this router, with the change coming at v 5.0. Mine is 5.0. You may have gotten an earlier version? At any rate, this is the link from whence my attempts ensued.

Also, as far as I have been able to tell, you cannot ascertain what version you are getting from looking at the box.

mbpark 09-06-2006 06:46 AM

I had a v5
 
I bought my v5 for $40 on eBay :).

It took me two tries, but I did get it up and running.

Mitch

tw 09-06-2006 07:28 PM

Quote:

Originally Posted by Elspode
Because the Open Source crowd has created hacked operating systems that let you do neat things with them...the neatest being that you can *increase the output power* of these things.

How does software increase power to a transmitter? WiFi outputs a full power and regulatory limited signal as defined by its unlicensed frequency band. How is this changed by software?

mbpark 09-06-2006 08:51 PM

firmware
 
tw,

The firmware controls the transmit power of the radio via software.

You can adjust up to the max using the software.

Mitch

Elspode 09-06-2006 08:58 PM

I'm all aquiver with excitement waiting for the followup to this one...let me just go get some popcorn.:corn:

tw 09-07-2006 02:20 PM

Quote:

Originally Posted by mbpark
The firmware controls the transmit power of the radio via software.

You can adjust up to the max using the software.

Mitch

Which is true with cell phones. But WiFi runs 100%. With any power reduction comes a data bandwidth reduction. Why would a WiFi port ever reduce power from 100% when that automatically means a reduction of signal to noise ratio and therefore a data bandwidth reduction below 54 Mb? I don't recall seeing any mention of transmitter power reduction or power control in 802.11 standards. Either it was on or it was off.

zippyt 09-07-2006 09:10 PM

may be it reduces the packet size so insted of like 5 gallon buckets of data it is more like cups size packets , i know THAT can increse data flow ??

Just a thought , not an opinion .

glatt 09-08-2006 08:09 AM

Quote:

Originally Posted by tw
Which is true with cell phones. But WiFi runs 100%. With any power reduction comes a data bandwidth reduction. Why would a WiFi port ever reduce power from 100% when that automatically means a reduction of signal to noise ratio and therefore a data bandwidth reduction below 54 Mb? I don't recall seeing any mention of transmitter power reduction or power control in 802.11 standards. Either it was on or it was off.


I don't know jack about 802.11 standards and how they are acheived, but is it possible that the manufacturer designed the hardware to exceeding the 802.11 power standards? And to meet the standard, they could have used firmware to cripple the hardware's power and bring it down to the level of the standard? If so, then a change of the firmware could increase output to the level allowed by the hardware.

Griff 09-08-2006 09:27 AM

That's what I was thinking glatt. Is it possible that the output will exceed FCC limits?

MaggieL 09-08-2006 09:39 AM

Quote:

Originally Posted by tw
With any power reduction comes a data bandwidth reduction.

If power is sufficent for a readable copy of the signal, data bandwidth remains constant, unless you tweak the modulation scheme...I'm not aware of any provision for that in 802.11.

For example, your Wi-Fi won't run faster if you shorten the hop distance from 20 feet to ten feet at constant RF power. And there's no advantage to running extra power unless the path loss has made the signal marginally readable...when adding power can reduce the number of unreadable packets, and this increases your range and/or aggregate data rate, as does changing the antenna gain to focus available power in a specific beam direction...that's what a Pringles can antenna does.

http://www.defcon.org/html/links/dc_...6592636783.jpg
Above: the "Sniper Yagi" demoed by the Schmoo Group at DefCon in 2004. Alleged to have 10 mile (15km) range.


Quote:

Originally Posted by Wikipedia
Wi-Fi uses the spectrum near 2.4 GHz, which is standardized and unlicensed by international agreement, although the exact frequency allocations vary slightly in different parts of the world, as does maximum permitted power.

Given the above, I'd guess that controllable power allows conforming the unit to regulations in various countries by changing the software config only.

I should add that S-band--the other name for 2.4 GHz--is not actually unlicenced...only the WiFi usage under FCC regs Part 15 is. Amateur Radio has a licenced primary allocation.

Elspode 09-08-2006 09:30 PM

It should also be noted that more costly routers *do* have a higher output. I believe that the power level for home gear is some combination of "don't step on the neighbor's toes very much" and "hey, want better performance? buy this more expensive Professional Router!".


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