Mikrotik R52Hn and txpower issues

RouterOS Wireless Networking
1

Hi,

I’ve purchased a new R52HN mini pci card for my Linux router to have 5 Ghz 802.11n capability at my home network.
Previously I had a AR5413 chipset based miniPci card which provides 802.11g at 2.4 Ghz.

My router has Ubuntu 12.04 OS on it and the wireless regulatory domain is set to EU (Europe)
So, I believe at channel 36 , I should be able to go up to 20 dBm with no issues.
And the R52HN seems to support it.

But when I run hostapd with following configuration, I get limited to 17 dBm power output.
The antenna is connected to J4 on the R52HN
I get very poor wireless reception at home.

Even with channel bonding, all I get is max 81Mbs on my Windows PC client.

What is wrong that I’m doing ?

country_code=EU
ieee80211d=1
ht_capab=[HT40-][HT40+]
channel=36
bridge=br0
driver=nl80211
hw_mode=a
interface=wlan1
rsn_pairwise=CCMP TKIP
ssid=xeonw5
wpa=3
wpa_key_mgmt=WPA-PSK
wpa_pairwise=CCMP TKIP
wpa_psk_file=/etc/hostapd/hostapd2.wpa_psk
ieee80211n=1
wmm_enabled=1

Btw, I’m willing to change regulatory domain to anything that would supply more power and solve my wifi reception issues.

iw reg set EU command output on dmesg:

[  983.151076] cfg80211: Regulatory domain changed to country: EU
[  983.151093] cfg80211:     (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)
[  983.151119] cfg80211:     (2402000 KHz - 2482000 KHz @ 40000 KHz), (N/A, 2000 mBm)
[  983.151144] cfg80211:     (5170000 KHz - 5250000 KHz @ 40000 KHz), (N/A, 2000 mBm)
[  983.151168] cfg80211:     (5250000 KHz - 5330000 KHz @ 40000 KHz), (N/A, 2000 mBm)
[  983.151194] cfg80211:     (5490000 KHz - 5710000 KHz @ 40000 KHz), (N/A, 2700 mBm)

root@router:~# iw reg get
country EU:
        (2402 - 2482 @ 40), (N/A, 20)
        (5170 - 5250 @ 40), (N/A, 20)
        (5250 - 5330 @ 40), (N/A, 20), DFS
        (5490 - 5710 @ 40), (N/A, 27), DFS

hostapd command output:

root@router:~# /usr/sbin/hostapd -dd -B -P /var/run/hostapd3.pid /etc/hostapd/hostapd2.conf
Configuration file: /etc/hostapd/hostapd2.conf
nl80211: Interface wlan1 is in bridge br0
nl80211: Add own interface ifindex 4
nl80211: Add own interface ifindex 5
Failed to create interface mon.wlan1: -23 (Too many open files in system)
Try to remove and re-create mon.wlan1
nl80211: Remove interface ifindex=11
nl80211: New interface mon.wlan1 created: ifindex=12
nl80211: Add own interface ifindex 12
BSS count 1, BSSID mask 00:00:00:00:00:00 (0 bits)
nl80211: Added 802.11b mode based on 802.11g information
Allowed channel: mode=1 chan=1 freq=2412 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=2 freq=2417 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=3 freq=2422 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=4 freq=2427 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=5 freq=2432 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=6 freq=2437 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=7 freq=2442 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=8 freq=2447 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=9 freq=2452 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=10 freq=2457 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=11 freq=2462 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=36 freq=5180 MHz max_tx_power=17 dBm
Allowed channel: mode=2 chan=40 freq=5200 MHz max_tx_power=17 dBm
Allowed channel: mode=2 chan=44 freq=5220 MHz max_tx_power=17 dBm
Allowed channel: mode=2 chan=48 freq=5240 MHz max_tx_power=17 dBm
Allowed channel: mode=0 chan=1 freq=2412 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=2 freq=2417 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=3 freq=2422 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=4 freq=2427 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=5 freq=2432 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=6 freq=2437 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=7 freq=2442 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=8 freq=2447 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=9 freq=2452 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=10 freq=2457 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=11 freq=2462 MHz max_tx_power=20 dBm
RATE[0] rate=60 flags=0x1
RATE[1] rate=90 flags=0x0
RATE[2] rate=120 flags=0x1
RATE[3] rate=180 flags=0x0
RATE[4] rate=240 flags=0x1
RATE[5] rate=360 flags=0x0
RATE[6] rate=480 flags=0x0
RATE[7] rate=540 flags=0x0
Scan for neighboring BSSes prior to enabling 40 MHz channel
Scan requested (ret=0) - scan timeout 10 seconds
Interface initialization will be completed in a callback
root@router:~#

Btw, I am not sure if this is the correct place to post this issue. Please let me know where I should post if I’m doing wrong.

Thanks.

2

Use routeros :smiley:

3

thanks but I have several additional apps on the Ubuntu OS working on my router.
i.e. IP PBX(Asterisk) , Ntop, customized DNS and mail server etc.

So I can’t use RouterOS.
How can I solve the issue on Ubuntu ?

is it regulatory limitation, or my hardware ? (R52HN)

4

The tx power is probably offset by about 5dB. I’m sure someone will comment to confirm or deny, but generally that is what you find on higher powered cards.

By default an XR2 or XR5 show 18dB, but they have a 10dB offset, so the actual max tx power is 28dB even though the OS shows 18.

5

Thanks but…
even if you are correct with that assumption, we have a fact that my wifi reception at home (not a very large apartment floor) is very low.
I also have my old card working at 2.4 Ghz and this card has very stable wifi reception with 54Mbps allover the house.

So the R52HN performance is low. How can I fix this ?

thx.

6

I still couldn’t find a solution. Any ideas ?

7

Routeros + metarouter for additional app. :smiley:

Try some other contry code.

8

I’ve tried other country codes with no luck.
Then I decided to move wifi features out of the box to an access point.
I will use a Linksys EA4500 for wifi connection.

But I’d like to understand why R52HN fails with my setup. Do you have any troubleshooting methods for this ?

9

Could be a bad card.

Did you ever run the card without an antenna? These burn up pretty quick if you do.

10

but setting txpower is rejected through OS (kernel/kernel module)
so it shouldn’t be a hardware issue , am I wrong ?

11

No, a hardware failure shouldn’t cause a problem setting the tx power in software.

12

I’ve tried setting to 27 dbm with no AP configuration. It was accepted.
When I make an hostapd conf with 2.4 Ghz, I can only go up to 20 dbm
When I make an hostapd conf with 5 Ghz, I can only go up to 17 dbm

So it seems to be related to reguations (regulatory domain settings)
How can I force going to more dbm with 2.4 or 5 Ghz ?

13

no ideas ?