IMEI Blacklist from Local Band 20 Signal

[WilliamDalley]

Hello,

I am an EE Small Business customer who has been using Mobile Broadband for the last 12 months to power my business network due to my rural location. Up until around 2 months ago, the mobile broadband has been great as I have a nearby cell tower that emits, solely, a Band 20 4G signal. 

Recently, however, my Mobile Broadband router will not connect to the Band 20 signal and is instead only connecting to a very poor Band 3 signal from a cell tower several miles away. EE coverage checker shows no local faults or issues and my personal mobile, also EE, remains powered by my nearby Band 20 tower.

To diagnose the issue, I have tried many restarts and other generic online ideas but to no success. I have also swapped out my Mobile Broadband data SIM with my personal SIM and my router still can only connect to the poor Band 3 signal and not the stronger Band 20... It appears that my router has potentially been blacklisted from my local cell tower, perhaps using the IMEI number of the router... I cannot find any confirmation that this is exactly what's happening but I can find no other explanation. My router is a Teltonika rather than EE, but it is up to date and has had no changes from when it was working well originally to the poor broadband now.

If anyone could provide any ideas or information about what could be happening in my current situation that would be great. Unfortunately, trying to convince EE telephone support of the technicalities of my issue is proving to be impossible.

[bristolian]

If blacklisting were the reason, the affected device would be unable to connect to any EE site of whatever flavour.

More likely is that the router/network are deeming the B3 carrier usable, and therefore preferable to B20 which is always a layer of last resort. Can you be more specific about the service issues you're having?

What are the RSRP, RSRQ & SNR figures that both devices report for B3 & B20?

[WilliamDalley]

Hi Bristolian,

Ah okay, that's interesting...

When my router is connected to the Band 3 signal I have RSRP: -120, RSRQ: -11, SINR: 6... which, as the poor signal indicates, provides very weak data throughput. Unfortunately, I do not have an exact record of the previous signal strength when I could receive the Band 20 signal to the router, but I remember that my RSSI was typically around -65 to -70dBm, whereas now on the Band 3 signal I have an RSSI of -89dBm. 

As I previously mentioned, my EE mobile phone still connects to the Band 20 signal by default in the same location, but when I try to force my router to only connect to Band 20 signals through the LTE settings within my router, I then receive absolutely no connection.

I'm aware that EE restrict their Band 20 network from EE PAYG and Lyca Mobile customers, which they must do through the SIM, however, to me, it feels like I have become restricted in the same way but perhaps through the router IMEI, as when I replace the SIM in the router with my phones SIM I still can only connect to the Band 3 signal.

I'm struggling to come to any conclusions other than my router is being restricted from connecting to EE's Band 20 signals via its IMEI, device ID, etc., or that my router's modem is malfunctioning. The second option is extremely unlikely as I previously mentioned this issue has occurred entirely out of the blue and not after any software updates, etc.

[bristolian]

Some interesting symptoms. RSRP around -120dbM is cell-edge, the RSSI is not directly comparable so the picture isn't totally complete.

The router getting no throughput on B20 is odd - I'd expect it to get some, even if priority steering then encouraged a move to B3 primary carrier. Historically B20 access didn't use the IMEI as different SW builds could also have an impact on the same device.

I will have to ponder on this case.