Hello , trying to figure out an issue with 5G where I live, I live about 16 kilometers away from the serving mast from Three Ireland with direct line of sight. Ill link the thread below but basically with even more detail.
I have a netgear MR5200 + Mikrotik chateau 5G , and a samsung S20 + A52 5G and they all cannot connect to the 5G from home. The *#0011# SIM information readout on my S20 says : RACH_PROBLEM and the 5G symbol keeps flickering from outlined grey to white over and over.
I initially thought in the past the 5G symbol flickering from outlined 5G to full white was something to do with N78 band being unable to synchronise the uplink since I am 16km away. Three Ireland upgraded the site and deployed N3 here so I thought I should have no problem getting that but the same issue occurs. Regardless of where I select N3 only on the mikrotik 5G router or not. However the A22 5G has no problem getting 500 Mbps down and about 60-70 Mbps upload and it connects to both N78 and N3.
One thing to note is my S20 connects to N78 and N3 on every other site I’ve been to while travelling and also when I drive closer to my serving cell. It just seems to be unable to from home. I assume the routers would be able to as well.
It will just keep failing to connect every few seconds… on the chateau 5G it is something similar. It will show N3 for a second or two then disappear and all the bands will aggregate differently. It will keep doing this in a loop every few seconds and will not hold onto the N3 connection. There is more than adequate signal.
I manage to catch a screenshot of when it briefly connected before losing it.
I then tested my partners A22 5G phone connects no problem though with really good speed results, on both N78 and N3. I was really surprised about being able to connect to N78 since I am 16 km away.
The common thing between my devices is they all have a snapdragon X55 modem. and the A22 5G has a Mediatek Dimensity 700.
Why is the mediatek able to connect no problem whereas my other 4 devices all have this same issue. Is there a way to rectify this ?
Dear Sir,
Thanks for your asking.
I guess you are using a CPE device that embedded our nr5G module, right? which module do you use? you could use ati command to get the information.
Do you mean your device(X55) can not register n78 SA but the other device(MTK 700) can register n78 when you are 16km away the base station?
If yes, please help to get the returning results of at+cgatt?/at+cops?/at+qeng=“servingcell”, and help to provide the QXDM log to us also.
By the way, it will be better to ask the question from the CPE device company.
Thanks!
the X55 devices get stuck in an endless loop trying to register n78 NSA and N3 NSA . The MTK 700 device registers successfully with n78 NSA and N3 NSA - both at the same location 16km from the base station.
The X55 cannot
I attached the screenshot of the commands you said, and I used winbox through the router to print a log as I have no access to QXDM
I have contacted mikrotik also , but I was told to ask here too
Dear Sir,
From the log you provided, your device has already registered the LTE B28, can you access the network now? Because NSA will only engage during large downloads, so you could do that to test again.
I have no problem with LTE, the problem is , the N3 connection will not stay longer than 2-3 seconds, no matter what on 4 different devices with the same snapdragon X55 network modem when I am trying to connect to the cell from home.
but with an A22 5G phone which has a MTK700 modem, there is no problem , and speeds are insanely better despite having better signal on the devices with the issue. Speed test using the A22 5G below.
The X55 devices are not even close to this because they cannot establish N3 or N78 NSA , is this potentially because the MTK700 has a faster processor that is able to maintain connection at longer distances? or?
Is there a firmware fix available for this?
To rule out weak signal being a problem , I managed to get -88 RSRP on N78 on my snapdragon X55 device 16km away by taping my phone to the LNB area of a 80 CM offset parabolic dish and pointing it directly at the cell tower … the RACH_PROBLEM still occured, flickering 5G symbol constantly dropping the connection even with a strong signal for this distance. So signal is not the issue.
About your issue, we need QXDM log or qlog to check more. Please ask your device manufacturer to assist you.At the same time, please help to reply below questions, so we can ask related colleagues to help you too.Thanks!
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From which distributor do you buy Quectel modules & EVB kits &?
