RB922UAGS-5HPacD + R11e-2HPnD constantly dropping connections on 2.4 Ghz network

RouterOS Wireless Networking
1

Hello.

I’ve created a dual band access point for my home (87 square meters apartment) based on the following components:

Board: RB922UAGS-5HPacD + R11e-2HPnD
Case: CA411-711
Antenna: 4 x ACSWIM
Power: 24V, 1.6A
OS: version: 6.33.3 (stable)

Attached a small diagram with the box and the antenna configuration & positioning.
Unfortunately I have a lot of problems with the clients connecting on 2.4 GHz network.
The AP is constantly dropping connections with these clients (throwing “disconnected, extensive data loss” messages).
These clients are mobile phones and tablets. Didn’t tried with laptops because for laptops I use the 5 GHz network (Intel 7265AC adapters).

Things I’ve tried to solve the problem:

  • upgrade RouterOS version to latest
  • reset to factory defaults
  • move/spin/re-position the antennas
  • change channel width from 20/40MHz Ce to 20 MHz
  • change frequency
  • enable/disable WMM Support
  • change advanced setting “Distance” from dynamic to indoors
  • change TX Power Mode from default to “all rates fixed”: using first 17 dBm, then 14 dBm

Nothing helped solving the problem.

The equipment is configured as bridge, and is using the Ethernet port to connect to my main router RB850Gx2.

Before upgrading to this hardware configuration I was using the following:
for 2.4 GHz AP: RB2011UiAS-2HnD-IN
for 5 Ghz AP: RB911G-5HPnD
and I never had problems with WiFi.

Any ideas on what might be wrong with the equipment?
Thank you.

2

What’s the RB922 firmware?

Are you using the same channel you used with the 2011? Have you tried the 2011 with the same channel to rule out interference or overlapping?

Have you done an spectral scan/history on 2,4GHz band?

3

Firmware info:
firmware-type: qca9550
current-firmware: 3.24
upgrade-firmware: 3.24

I’m using the same channels as on RB2011. I did not perform any scan on 2.4 GHz spectrum.

Edit:
Scan performed on 2.4 GHz
FREQ USE NF
2412MHz 6.5% -97
2417MHz 2% -100
2422MHz 0% -100
2427MHz 0% -100
2432MHz 29.7% -98
2437MHz 6.5% -98
2442MHz 2.6% -98
2447MHz 16.4% -99
2452MHz 0% -99
2457MHz 1.1% -99
2462MHz 3.4% -98

4

Apart from ruling out pigtails if you can by trying others, and making sure the mini-pcie card is firmly seated on its slot, I’m out of ideas, I’d make a supout file, pics of the assembled board and mail it it along with your export to support.

5

some people have rumored some power problems on that setups

just to discard that i suggest to:

try to regulate tx power on both radios to lower power consumption
try another power supply
try powering directly from power supply not POE

like pukkita says pigtail and antennas on 2.4ghz radio can be related too

6

I have perfomed 2 changes:

  1. I have re-seated the R11e-2HPnD card


  2. I have changed the antennas between them, by switching the connectors. Now the 2.4 GHz AP is using the former 5GHz antennas and the 5GHz one is using the former 2.4GHz antennas.

Regarding power supply, unfortunately I don’t have another one.

What about antennas? Is there any way to see in RouterOS if the antennas are good or bad, or if one of the antennas has a connectivity issue?
I’m thinking that maybe there could be some radio params in the OS that can be checked, in order to see if all antennas are detected and they’re emitting/recieving functions are ok or not.

Thank you.

7

Are you experiencing problems in 2.4 after those changes?

Antennas are passive devices, AFAIK there’s no way for you to check for that from RouterOS.

Mikrotik however could infer antenna or pigtail problems from supout files and point you to them.

Powering on any radio without antennas (unloaded) could damage them.

I doubt the antennas being the problem as long as the pigtails are fine.

There have been reports of issues with add-on radio cards as chechito points out, try lowering the power… The card you’ve chosen can draw 7W by itself…

922 max draw is 17W, r11e-2HPnD max draw is 7W, so max overall draw would be 24W, or 1A at 24V, and your PSU is 1.6A, so your PSU sizing seems to be fine.

A test you could do is disabling the 5GHz wlan interface and test only the 2,4GHz performance. If it performs fine, you rule out the r11e-2HPnD card and its antennas/pigtails being the problem.

Write support and ask… attach the export and a supout file.

8

Until this moment it seems that 2.4 GHz AP is stable, but I think it’s too early to be sure it’s completely solved. I will come back later with some more details about stability.

I did not power the boards without connected antennas. They have a big label on them warning of this exact thing.

By pigtails I suppose you mean the black cables that are coming out of the antenna base, am I right? (not quite familiar with the terminology). If this is the case, the antenna cables look fine, not bended or with loose connectors. They look intact.

9

I did not imply you have powered the radio w/o antennas attached, but that if it were possible to “sense” this, RouterOS will disable them in the event of not detecting the antennas.

did you disable the 5GHz interface?

Yes, the pigtails are the cables connecting the antennas to the MMCX connectors. Forgot that SWIM antennas have it soldered to the antenna side.

Another thing to check, is the MMCX connector positively “clicks into” the PCB socket securely.

If you don’t feel that click, it isn’t making a secure connection and could be the cause of your problems.

10

Hi guys.

Coming back with some more feedback:

2.4 GHz AP looks stable (after about 10 hours from performed changes).
5 GHz AP looks stable
MMCX connectors are ok. They do click when pushed into the PCB connectors.

I did not disable the 5GHz interface (yet). I’m waiting to confirm first 2.4 AP stability for at least 24 hours.
Tomorrow I will post back another status.

Thank you.

11

Hello.

Latest updates on the problem:

  • 2.4 GHz AP is stable (no more extensive data loss disconnections) - no more comments here

  • 5 GHz AP seems to be unstable now (getting disconnections with following reasons)

  • disconnected, extensive data loss

  • disconnected, received deauth: unspecified (1)

Later edit: it seems that 5GHz problematic behavior is not persistent. Now it seems ok. Using “auto” frequency.

12

what changes you made to get the 2.4ghz interface stable??

13

These were the changes:

  1. I have re-seated the R11e-2HPnD card
  2. I have changed the antennas between them, by switching the connectors. Now the 2.4 GHz AP is using the former 5GHz antennas and the 5GHz one is using the former 2.4GHz antennas.