Question

Hi

I've recently installed an rutx50 with four external antennas onto a ship and it operates fairly well.

A problem I've had, is that the modem always connects to strongest signal strength tower and due to the remote areas of operation, this is often a tower which only offers LTE band 28, with very low capacity, hence throughput is poor.

The only way I've managed to fix this issue is to disable LTE band 28 entirely, which then causes the modem to connect to a larger tower with multiple bands and high capacity, be it at lower signal strength, but due to CA on theses towers, the throughput is much better.

Question is, I don't really want to disable band 28 entirely, I just want the modem to not use band 28 by itself, this is because the low capacity towers nearly always only have band 28 and thus disabling band 28 stops the modem using theses small capacity cell towers.

The larger towers also have band 28 in a much larger capacity, thus i would ideally like to utilise band 28 when the modem is connected to theses towers, hence my question is, ia there a command or way to make the modem only utilise band 28 when using CA with another band?

Answer 1

Hello,

 

Unfortunately, there is no way to restrict Band 28 to be used only as a secondary carrier in specific circumstances. I did not find any relevant AT commands in Quectel's documentation that would allow you to use a specific band only as a secondary carrier. As a result, without completely disabling Band 28, there is no guarantee that this band will not be used as a primary carrier.

 

You can consider cell locking (information here) which allows you to specify a certain band as the primary carrier, while other bands can be secondary carriers. However, this approach might not be suitable for your case, as it seems you are constantly travelling and connecting to different cells. 

 

Kind Regards,

Andzej

Comments

Hi

Thanks for your help much appricated, yes unfortunetly we are a roaming structure (ship) and hence locking to a particular cell will eventually cause issues.

The problem isn't band 28 LTE itself, the issue is alot of small cells exist along the coast, next to larger multiband 4G/5G cells. all theses small cells use LTE B28 only and usually only have 1x1 transmitter. If there was a way to somehow instruct the modem to avoid theses towers, my problem would be resolved.

Anyway as there doesnt seem to me a solution for now I will just keep band 28 LTE disabled but it's a shame because the larger towers, do have alot more B28 bandwidth / capacity.