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Topic: Which router really support 501 mW TX Power?

The content of this topic has been archived between 25 Apr 2018 and 1 May 2018. There are no obvious gaps in this topic, but there may still be some posts missing at the end.

How many topic talk about people that aren't able to set the max wifi tx power to 501 mW (27 db)? a big number..
In the large part of these cases the problem is due to an hardware limit of the router. So, someone know or have a direct experience with some router running OpenWrt that support the max tx power?
Maybe usefull to do a list, just for ones that want to use it as wifi repeater or very long wifi link. :-) I'll keep updated this first post. Thanx!

First devices tested:

Router                                         Max TX settable power    Options

TP-LINK WR842ND                       27 dBm (501mW)            Bolivia (BO) country regulation
TP-LINK WR841ND                       27 dBm (501mW)            Bolivia (BO) country regulation & compiled with Force Atheros drivers
TP-LINK WR1043ND                     24 dBm                            Bolivia (BO) country regulation & compiled with Force Atheros drivers

(Last edited by <Lork> on 26 Jun 2013, 14:13)

I found this:

TP-Link TL-WR1043ND

Wireless:    Atheros AR9103 2.4ghz 802.11bgn
Wireless Power:    Maximal power output is 27 dBm (500 mW)

http://wiki.openwrt.org/toh/tp-link/tl-wr1043nd

Someone can confirm it?

I have this router, but I don't know how to measure it. Openwrt has limits, because it obeys regulatory rules, but I have seen jow's hack, which unleashes the power this router has, it is for atheros chipsets, so maybe applicable for different brands too. I have not tested the hack yet, bercause I don't want to attract attention by poisoning the air with my wifi only, when it works within rules just fine.

Thanks nozombian for answer.

I don't think that you create a "black hole" if you put wifi at top power ;-) , above all if you use it with Yagi antenna for long link as supposed in this topic.

Anyway i think that if someone in wiki wrote "Wireless Power:    Maximal power output is 27 dBm (500 mW)" maybe that you can check it without doing hack, with "iw" or "iwlist txpower" command via SSH. If you can, please try.

I found also this topic http://www.gargoyle-router.com/phpbb/vi … amp;t=3032 about this router but i haven't seen any hack in the german page, just setting US country in wifi option. Have you got a link for jow's hack?
I have a TP-LINK WR842ND (not so different, but i think that hardware doesn't support 502 mW of tx power..hoping to be wrong).

I know that I won't kill someone by increasing the tx power, cell phone has 2W and is supposed to be held by the ear smile But I live by the rules and I don't trespass until necessary wink

For the last time I have seen the hack discussed in here: https://forum.openwrt.org/viewtopic.php … 32#p205532

Don't forget, that wr1043nd has 3 antennas, so you should have 3 yagis for best results and cable as short as possible big_smile I'd recommend nanostation m2 or nanobridge for longer distace links, practically the same hardware as wr1043nd, but they have mimo antena built in already and are suitable for outdoor use.

(Last edited by nozombian on 25 Jun 2013, 13:37)

Thanx for info, but don't worry you don't kill anyone with a router in an-plen-air and high directional antenna..

I've a TP-LINK WR842ND (two antennas, 300M, ..) and testing with IT country i can max set 100 mW (20 dBm). Instead using US country i can set effective max 125 dBm (21 dB) but the top option is 501 mW. I'm planning to test this with a cheap but high gain antenna "TP-LINK TL-ANT2424B Antenna 24dBi 2.4GHz " hoping to cover long link as 20-30 km in mountain (so you understand that i can't kill anyone..).

I'll chek hack's link and the nanostations, i've already hear about them. :-) thankx from Italy!

If someone else have more infos about routers with hardware support to 501 mW tx power pleas post it!

I told you that I don't worry, 2W used by any cell phone at nearly the same frequency has 4x more output power than any router is capable wink

It is really possible to make 30km link on 2.4 GHz, we used em 10 years ago in here, but now it is problem to make a reliable and fast connection to a neighbour living across the street, 2.4GHz and 5GHz wifi bands are very noisy in here sad I'd not buy that tp-link antenna, it is better (and maybe even cheaper) to buy nanostation or nanobridge for this purpose.

Of course, that you have to "see" the other side, but for that long distance I'd recommend using 5GHz nanobridges with 25dBi antenna, or better yet some system for long distance links, we use alcoma systems here (www.alcoma.com), they are much better than nanostations, but also much more expensive.

Btw. nanostations has "compliance test" in country setting, which will enable you to use frequencies outside the band and 27dBm output power. Of course, such setting would violate rules and cause intefrence with radars, military systems, aircrafts, or God knows what, but nanostation M5 allows me to choose between 4920-6100MHz smile Legally is the band much more narrow, depending on the country.

many many thanx nozombian!
Sorry for my english that's not fine...
I'll go deep inside nanobridge opportunity, seems to be interesting! they would be perfect if they would be at 12 volt instead of 24 (for fotovoltaic), and just a bit expensive (180 €)

But just for this topic interest: if you have your router in hand, can you try for a second to set via LuCI US country and the top option in tx power (501 mW) and then save, apply and post here what is the real max tx power value. I suppose that you'll get my same result..this router isn't so different from mine tplink wr842nd

http://img441.imageshack.us/img441/4350/nn8q.png

Nanostation M5 has 15V power supply from stock and works with 12V just fine. It may depend on the length of the cable, but if you have short ethernet cable such as 10 meters from poe, it is not a problem.

Btw it is possible to install openwrt on nanostations too, but ubnt firmware is more stable, does not have bugs with wifi, which openwrt has on atheros and ubnt has all features you need on a wifi bridge, plus you can select nonstandart frequencies, which is not possible on openwrt (maybe with hack, but I don't know).

I have routers by hand, but I don;t have luci installed. There's option txpower, which never worked for me (without jow's hack), but I can try it, but not now, sorry.

(Last edited by nozombian on 25 Jun 2013, 16:39)

There is no single router I know of that supports 500mW tx power setting. That value is merely the theoretical upper bound allowed by legal regulations. Physical hardware limits are usually way less and my hack will change nothing about it.

When I set country 'US', option txpower 24 on wr1043nd does not work, reports invalid argument, but when I select country BO, it works up to 24 dBm, then it reports invalid argument too. With country set to CZ, I can set only up to 20.

But with jows hack it should be possible to set 27, but as jow told, it is theoretical wink

(Last edited by nozombian on 25 Jun 2013, 16:54)

Many thanx to both!
@Jow so that's not what i was hoping :-(

@nozombian Many thanx for infos about nanobridge! i think that in my case they will be perfect to do the job. Thanx for tryied to test txpower on your router, so if it can't goes up to 501 mW, maybe that the wiki must be updated...

I've just played with my WR842ND and i'm a bit confused: when i set US contry, max txpower EFFECTIVE is 21 dB (125 mW) even if i set it via luci to 501.
If i set country to Bolivia, magic...seems that router have an effective tx power of 501 mW (27 dB). I'can't understand why, if is a bug or someonelse. I can understand hardware limit that (under US contry settings) set max tx to 21, but this must be the same in other country (if this is just a software option that doesn't match with a real txpower switch).

US

root@OpenWrt:~# iwlist txpower
lo        no transmit-power information.

eth1      no transmit-power information.

wlan0     unknown transmit-power information.

          Current Tx-Power=21 dBm       (125 mW)

eth0      no transmit-power information.

br-lan    no transmit-power information.

After, BO

root@OpenWrt:~# iwlist txpower
lo        no transmit-power information.

eth1      no transmit-power information.

wlan0     unknown transmit-power information.

          Current Tx-Power=27 dBm       (501 mW)

eth0      no transmit-power information.

br-lan    no transmit-power information.

Openwrt follows regulations, Bolivia probably hasn't limits for 2.4GHz band, that's why you can set bigger limit for that country. I tried to set 27 dBm with BO on my wr842nd too and it works too (have it compiled with Force Atheros drivers to respect the user's regdomain settings). Wr1043nd is probalby limited to 24 somehow, I have them compiled with the same settings.

Edit: on wr841n 27dBm works with Bolivia too.

(Last edited by nozombian on 26 Jun 2013, 12:50)

Thanx for testing!
Anyway there is something that is wrong because after reboot TX effective power was still at 21 dBm. After re-change to US regulation and set 27 dBm...now seems that it works even with US country ?!?! When i have much more time i'll try to test with some low cost instrument if there is real increase from 21 dBm to 27 (virtual) dBm.
I'm updating first post with this two device. :-)
Anyway nanobridge must be more powerfull for long link.

Yes, nanobridge is powerful. It allows you to go way beyond limits, has a big antenna and no loss in the cable, because board is connected directly. I know about nanobridge link, which works even through a forest without visibility and they are about 1km distant. They surely don't respect regulations smile

I noticed, that I can set 27 dBm on wr841n too, even when I have returned country to CZ, which is surely beyond limits smile But it looks like the signal is still the same.

I tested yet on wr741nd and I'm unable to set more than 17dBm without invalid argument error, not even with country 'BO'.

(Last edited by nozombian on 26 Jun 2013, 23:09)

WDR-4900 does 30dbm on 2,4ghz band running barrier breaker.
It covers my garden verry well. Better thatn WDR-4300 did in the past.

(Last edited by derdigge on 19 Jul 2013, 16:09)

A few weeks back I went up a local hill about 9 miles from my town to play with a TP Link 702n. I had with me a laptop and 18 inch satellite dish with an adjustable cardboard support to hold the 702 at the focal point and a 12 inch square 30 degree horn made out of cardboard and AL foil feeding a 4 and 1/4 inch square waveguide that I could mount the 702 a quarter wavelength from the reflector at the end of the guide. With just the 702 I could see two weak signals from town--one of them near the hill's base. With the 18 inch dish I was seeing 10 or more signals often 5 to 15 dB strength and with the horn about the same. The dish was hard to setup and aim. The horn easy to play with but kind of big. Seemed to me that any signal I saw was likely to be from an outdoor mounted device or from one that just happened to have a window in just the right place to leak out the signal.

As the 702 is rated at 100mW and the calculated dish gain is 20dB at 2.4GHz, the effective power in the direction the dish was pointed was 10W. Don't know why one would play with making a high powered omnidirectional router when a low powered, small one can be  mounted in a directional structure.

At 5GHz you can buy directional antennas built in and it is a better band than 2.4 for long distance use--though doing so would have some problems on a long term basis

(Last edited by jvvh5897 on 23 Jul 2013, 17:53)

Ohps. Should have adjusted that effective output power for the amount that the dish intercepts. That turn out to be about a fifth of the 100mW--so effective output directed by dish is about 2W.

(Last edited by jvvh5897 on 26 Jul 2013, 18:02)

jvvh5897 wrote:

A few weeks back I went up a local hill about 9 miles from my town to play with a TP Link 702n. I had with me a laptop and 18 inch satellite dish with an adjustable cardboard support to hold the 702 at the focal point and a 12 inch square 30 degree horn made out of cardboard and AL foil feeding a 4 and 1/4 inch square waveguide that I could mount the 702 a quarter wavelength from the reflector at the end of the guide. With just the 702 I could see two weak signals from town--one of them near the hill's base. With the 18 inch dish I was seeing 10 or more signals often 5 to 15 dB strength and with the horn about the same. The dish was hard to setup and aim. The horn easy to play with but kind of big. Seemed to me that any signal I saw was likely to be from an outdoor mounted device or from one that just happened to have a window in just the right place to leak out the signal.

As the 702 is rated at 100mW and the calculated dish gain is 20dB at 2.4GHz, the effective power in the direction the dish was pointed was 10W. Don't know why one would play with making a high powered omnidirectional router when a low powered, small one can be  mounted in a directional structure.

At 5GHz you can buy directional antennas built in and it is a better band than 2.4 for long distance use--though doing so would have some problems on a long term basis

Many thanx for report. You are right when you say "Don't know why one would play with making a high powered omnidirectional router when a low powered, small one can be  mounted in a directional structure" but here i was in search of a router to connect a RP-SMA YAGI antenna! Not for the omni! Anyway also 5 GHz would be interesting..but i don't know if i can use openwrt on them.

I have the following power setting available on a WD N750

I'm running OpenWrt Barrier Breaker r39770 / LuCI Trunk (svn-r9960)

2.4 Ghz - up to 27dBm (501 mv)
5 Ghz - up to 30 dBm (1000 mv)

I keep both channels low around 14 dBm to extend the life of the router (and mine) smile

Just because you can set those powers does not mean it is actually capable of them. Those are the regulatory limits not the limits of the router.

I've seen plenty of routers where I have inspected the hardware and seen it is only capable of 19-2dBm and yet dodgy drivers will happily report 30dBm all the time.

Hi.
I was reading the present topic and decided to see what is my WBMR-HP-G300H capable of.
So... according to the image, does this mean that the 30dBm is true?
I also see 30dBm in "iwlist txpower".
I use BB Trunk (41050).

http://s18.postimg.org/imunrlb21/16_6_2014_2_05_19.png

No.

Why not?
CommView for WiFi in Windows, also reports 30dBm.

http://s29.postimg.org/ak3ql3y7b/buffalo.png

I already told you. Just because some unofficial software misreads it does not mean it is true.

(Last edited by qasdfdsaq on 16 Jun 2014, 22:08)