[uruiamme]

I want to determine the maximum power output of a router and compare it to what my regulatory domain permits. I have a few Atheros routers, and I can never keep them straight as far as what is and isn't allowed.

Right now, I have a Netgear WNDR4300 router operating at 26 dBm on ath0 (2.4 GHz band) and 24 dBm on ath1 (5 GHz band). The regulatory domain is Canada.

Is this setting made by trial and error, or is this something I can lookup in a log file?

Because I am currently setting up a similar router made by TP-Link, the WDR4300. Despite the similar names and similar hardware, this one is only showing 20 dBm and 21 dBm, respectively. I also set it to Canada, and of course I tried the 26 and 24 dBm settings like on the Netgear.

Can anyone point to an easy way to determine if this is a hardware issue or something that can be changed? I don't know where to find published maximum power or whether there is a commandline shell query that can be done. Or is there a logfile? I tried dmesg, but the WDR4300 has nothing about the power output. Maybe nvram???

I'd like to know for my other Atheros devices, too.

Furthermore, there is surely a lot of confusion on how to adjust this setting. I'd like to help clear it up. For those new to it, basically the first step is to select your regulatory domain on both ath0 and ath1 under advanced settings. (Usually, this is the country where you are located. It may be default to Germany, which is unlikely to be what you want.) Save, Apply, reboot. Then the power settings should have some affect on the router's power level. A nearby dd-wrt or Wifi sniffer should be able to show you the change in power. I have an old version of inSSIDer (version 3.something for Windows) that works well and is freeware.

[mrjcd]

[uruiamme]

[mrjcd]

http://dd-wrt.com/wiki/index.php/QCA_wireless_settings

You want your devices at full power, correct?
Just set Tx power to 30 on both radio and you will get max that radio can do.
Reg Domains --- you should probably stick within your country but Canada usually allows for one of the highest
power settings. New Zeland, Haiti, Germany, are a few that will allow broader channel range. Channels outside
of what your clients (cell phones other wireless NICs) are set for will be absolutely useless to you.
2.4 channels outside of the 1 - 11 for North America are not normally allowed.
Certain situations US WiFi devices can legally use channels above 11
Canada can use 12 channels but ch 12 is suspposed to be at a lower power.
Japan can do all 14 channels but ch 14 is limited to 802.11b only per their rules.

Illegal settings outside what your country allows is not recommended.
However, if you live out in the sticks like some of us do you can play with whatever channel you want
... and yea ch 14 runs perfectly fine on the WRT54G as an 802.11g bridge ... but you are subject
to FCC fine if caught using as long range bridge....and such things are very easy to spot

[Fr3DBr]

USA = 20dbm 5.4ghz in WNDR3700, Australia 27dbm.

[uruiamme]

I was interested in how DD-WRT selected the power outputs for a particular, chosen, regulatory domain. I figured this out from reading the source code of DD-WRT. I saw this declaration:

const char *regdb_paths[] = {
"/lib/crda/regulatory.bin",
NULL
};

in dd-wrt/src/router/libutils/mac80211regulatory.c (See https://github.com/mirror/dd-wrt/blob/master/src/router/libutils/mac80211regulatory.c line 125)

This leads me to the regulatory.bin file, which seems to be from a Linux repository

https://www.kernel.org/pub/software/network/wireless-regdb/

The latest file (March 2017) is: https://www.kernel.org/pub/software/network/wireless-regdb/wireless-regdb-2017.03.07.tar.gz

regulatory.bin - The Linux wireless regulatory database

Description
regulatory.bin is the file used by the Linux wireless subsystem to keep its regulatory database information. It is read by crda upon the Linux kernel's request for regulatory information for a specific ISO / IEC 3166 alpha2 country code. The regulatory database is kept in a small binary format for size and code efficiency. The regulatory.bin file can be parsed and read in human format by using the regdbdump command. The regulatory.bin file should be updated upon regulatory changes or corrections.


You will want to browse db.txt in a program that wraps the text and newlines.


Notable countries from this list:
Australia, Belize, Guyana, New Zealand, Taiwan, and Venezuela. The United States is listed, too, but under slightly different criteria. All of these have relatively relaxed power and frequency (except the US) restrictions.

country AU: DFS-ETSI
(2400 - 2483.5 @ 40), (36)
(5150 - 5250 @ 80), (23), NO-OUTDOOR, AUTO-BW
(5250 - 5350 @ 80), (20), NO-OUTDOOR, AUTO-BW, DFS
(5470 - 5600 @ 80), (27), DFS
(5650 - 5730 @ 80), (27), DFS
(5730 - 5850 @ 80), (36)
(57000 - 66000 @ 2160), (43), NO-OUTDOOR

country BZ: DFS-JP
(2402 - 2482 @ 40), (30)
(5735 - 5835 @ 80), (30)

country GY:
(2402 - 2482 @ 40), (30)
(5735 - 5835 @ 80), (30)


country NZ: DFS-ETSI
(2402 - 2482 @ 40), (30)
(5170 - 5250 @ 80), (17), AUTO-BW
(5250 - 5330 @ 80), (24), DFS, AUTO-BW
(5490 - 5730 @ 160), (24), DFS
(5735 - 5835 @ 80), (30)

country TW: DFS-FCC
(2400 - 2483.5 @ 40), (30)
# Follow US 5.15 ~ 5.25 GHz: 30 dBm for master mode, 23 dBm for clients
(5150 - 5250 @ 80), (23), AUTO-BW
(5250 - 5350 @ 80), (23), DFS, AUTO-BW
(5470 - 5725 @ 160), (23), DFS
(5725 - 5850 @ 80), (30)

country US: DFS-FCC
(2402 - 2472 @ 40), (30)
# 5.15 ~ 5.25 GHz: 30 dBm for master mode, 23 dBm for clients
(5170 - 5250 @ 80), (23), AUTO-BW
(5250 - 5330 @ 80), (23), DFS, AUTO-BW
(5490 - 5730 @ 160), (23), DFS
(5735 - 5835 @ 80), (30)
# 60g band
(57240 - 63720 @ 2160), (40)

country VE: DFS-FCC
(2402 - 2482 @ 40), (30)
(5170 - 5250 @ 80), (23), AUTO-BW
(5250 - 5330 @ 80), (23), DFS, AUTO-BW
(5735 - 5835 @ 80), (30)

[uruiamme]

The regulatory domain list for all. (Updated 3/2017)

[tatsuya46]

for 2.4ghz power, australia i think has the highest in the world now after their revised rules, at 36dbm. their 5ghz is decent too minus a few removed channels from dumb dfs rules (like canada). but good luck finding any radio in an embedded device like a router that can take 36dbm &/or has their radio fw allow it yet.

26~30dbm is a common max without going into professional stuff, i dont mean $600 equipment, i mean $1000's+ & even then, still not all would do it (many seem to go the ultra high gain directional antenna method instead)

[Xeon2k8]

Saving all the hassle

https://git.kernel.org/pub/scm/linux/kernel/git/sforshee/wireless-regdb.git/tree/db.txt

[tatsuya46]

[Xeon2k8]

[ejaf]

Hi all...

Just for kicks, I changed my country of jurisdiction from US to AU.
My power on the 5GHZ ath1 gui screen is set to 50 dbm.

After applying the settings, the status page still shows 30 dbm.

Question is whether the status page is correct, or is it not being reflected. I would have expected to see 36 dbm, but then again, a lot of reading about this here and googling mentions that the extra may be about antenna gain, and not the base power.

I am running a Linksys EA8500 using latest build from Kong.

Any feedback appreciated.

E

[tatsuya46]

cause thats the max the hardware can do..

[ejaf]

Thanks

[mrjcd]