Supercharging Your Linksys Wireless Access Point

kwishot writes "Xam over at www.wi2600.org has documented a relatively simple way to 'turn up the juice' on your Linksys WAP11 Wireless Access Point." Caveats: the outlined method requires a Windows box, recent firmware, and (some) bravery, but no going inside the box or special hardware.

Comments

Ignorant Legality Question

[Uttles]

Does the FCC have a problem with a person amplifying their wireless network without some sort of license? I'm totally ignorant on the legalities of this, but it seems like a really cool tip for free amplification!

SNMP?

[omega9]

From what i can tell, this doesn't have to be a Windows only hack. The piece of software that Xam states is only built for Win32 seems to be nothing more then an SNMP manager. Now, the Win32 tool might make it a bit easier, but you can hardly call it "requires a Windows box".

The real trick

[LtBurrito]

The real trick is to get your neighbor to turn up his power so you don't have to buy your own...

Correction:

[clark625]

I goofed. The maximum radiated power is set at 1W. Not 1mW. Here's the FCC rules that apply, for those interested:

Part 15.247 covers intentional Radiators in the ISM bands that are the frequencies 902-928 MHz, 2400-2483.5 MHz, and 5725-5850 MHz. Besides covering the modulation schemes this part also covers the various power restrictions that the FCC has for devices like 802.11b. The critical section is 15.247(b)(1) through 15.247(b)(3)(i) quoted below:

"(b)The maximum peak output power of the intentional radiator shall not exceed the following:
(1) For frequency hopping systems operating in the 2400-2483.5 MHz or 5725-5850 MHz band and for all direct sequence systems: 1 watt.

(2) For frequency hopping systems operating in the 902-928 MHz band: 1 watt for systems employing at least 50 hopping channels; and, 0.25 watts for systems employing less than 50 hopping channels, but at least 25 hopping channels, as permitted under paragraph (a)(1)(i) of this section.

(3) Except as shown in paragraphs (b)(3) (i), (ii) and (iii) of this section, if transmitting antennas of directional gain greater than 6 dBi are used the peak output power from the intentional radiator shall be reduced below the stated values in paragraphs (b)(1) or (b)(2) of this section, as appropriate, by the amount in dB that the directional gain of the antenna exceeds 6 dBi.

(i) Systems operating in the 2400-2483.5 MHz band that are used exclusively for fixed, point-to-point operations may employ transmitting antennas with directional gain greater than 6 dBi provided the maximum peak output power of the intentional radiator is reduced by 1 dB for every 3 dB that the directional gain of the antenna exceeds 6 dBi."

Better range increase..

[Spackler]

The best way to increase the range of the linksys router is to not use a linksys card with it.

Switching from the linksys card to an Orinoco more than tripled my range! It also made me realize that the linksys router signal _was_ hitting the street (I thought it wasn't reaching my couch with the old card), and enlightened me to "War driving". If your having range problems in your house, it is more likely your card.

Re:Wireless Phone interference

[jandrese]

Well, since your phone is probably some analog deal that just blasts out your voice, I'd say upping the power on the access point will just add a bit more noise to your conversation (and probably not help too much in keeping the signal strong when you pick up the phone, although it should help a little).

A better hack might be to change the channel on your access point to something on the other end of the spectrum since you phone may not be taking up the entire band (unless it's a DSS phone). Or you might try moving your phone's base station and access point to opposite ends of the house.

PS: Whoever modded this as a troll: what were you thinking?

Good for overcoming line losses

[rcw-work]

At 2400mhz, 3-4db is equivalent to the loss in 45-60 feet of LMR-400 coax (or 12-16 ft of RG-58), according to this calculator.

For those that would like to put an 802.11b antenna on their roof without worrying about weatherproofing their access point, this may be just the thing.

bad engineering practice

[lophophore]

Since the 802.11b communications link is two-way, increasing the transmit power of only one end (the access point) is not going to buy you a whole lot. To increase the range, you need to either increase the effective power on both ends, or, more simply, put the access point up higher.

A higher gain antenna on the access point would help with both transmit and receive, and this is another option, however, I think that this might be illegal in the US.

Also, it is useful to recall that microwave ovens operate on 2400 MHz because this is the most efficient frequency for heating water. One watt is enough to cause some RF heating and potentially be hazardous to you health. Don't look at the business end of that yagi!

MIB hackery

[danish]

After installing the snmp utils (apt-get install snmp) and doing some minor surgery to the MIB so it would parse correctly, I think I've found the element to modify:

enterprises.atmel.atmelmib.atmelSys.TestModeSettin gsGRP.TestModeRadioConfiguration.0 = Hex: CA CA CA CA CA CA C9 C9 C9 C9 C9 C9 C9 C9

Although not in the same configuration as the article describes, this may be due to the fact that I've never upgraded the firmware on the access point I snmpwalk'd this from. Perhaps I should get busy on that....

Any of you people out there with an upgraded firmware, you should try snmpset under Linux or your UNIX of choice and see what kind of results you get... extra points for verifying the change with the Windows stuff in the article.

Numerically, snmptranslate says that the correct field is .1.3.6.1.4.1.410.1.1.8.8.0, assuming I'm using it right (I called it with the commandline snmptranslate -m +ATMEL-MIB -IR enterprises.atmel.atmelmib.atmelSys.TestModeSettin gsGRP.TestModeRadioConfiguration.0.)

Re:MIB hackery

[mmmbeer]

Nice job Danish. For noobs who just want to juice their WAP11 (192.168.100.250 is the IP addy of the Access Point):

apt-get install snmp
snmpset 192.168.100.250 public .1.3.6.1.4.1.410.1.1.8.8.0 x "80 80 80 80 80 80 80 80 80 80 80 80 80 80"

WARNING: I tried this hack...

[dstone]

...and my Pringles can burst into flames.