Energy consumption in NTN mode vs LTE-M

[ovrebekk]

Hi 

Have you done any benchmarking to estimate the difference in power consumption when comparing the nRF9151 in NTN mode vs LTE-M?

In particular I am curious if NTN has a similar behavior to LTE-M where the first network attach consumes a lot of energy, but where you can enter into a semi synchronized state in order to send subsequent packages at lower energy levels. 

Best regards
Torbjørn

[Simon D-M]

Hi Torbjørn,

Have you done any benchmarking to estimate the difference in power consumption when comparing the nRF9151 in NTN mode vs LTE-M?

Unfortunately, we currently still don't have proper benchmark on NTN power consumption.

It depends quite a lot if you want to use GEO or LEO satellites.

For GEO, I believe that a good way to get a very rough approximation of the power consumption is to think about it as a device that is on the edge of a cellular tower reach. So most of the reliability features are active and the output power and RX sensitivity are maxed.

And for LEO, it is more like you have a medium to poor connection, but the network "unreliable" (as the satellites are moving, so there might be moments when not satellites are available) 

In particular I am curious if NTN has a similar behavior to LTE-M where the first network attach consumes a lot of energy, but where you can enter into a semi synchronized state in order to send subsequent packages at lower energy levels. 

I believe that GEO satellites supports eDRX and PSM, but I'm not too sure about the LEO ones, as I'm not too sure if it would even make sense to have such a thing for a LEO constellation. I'll have to ask this internally before telling you more about this.

Best regards,

Simon

[ovrebekk]

Hi Simon

Thanks for the response. 

It sounds like the protocol used by NTN is quite similar to LTE-M then? 
For some reason I just assumed it was a completely different physical layer. 

Regards
Torbjørn

[Simon D-M]

Hi Torbjorn,

Yes, NTN is actually very similar to NB-IoT. Here is a little introduction on NTN (link).

This even says:

But what is 3GPP NTN actually? Put simply, it is NB-IoT via Satellite instead of cell towers. The introduction of 3GPP NTN means that you now have several new cellular networks you can access in a similar way to terrestrial LTE-M/NB-IoT networks

And if you have a nRF9151 SMA DK, you can also try evaluating NTN following this.

Best regards,

Simon