Impact of AT&T sunset on LX40 with roaming SIM

AirLink Routers AirLink routers
1

We use a few LX40 routers in the US but with international roaming SIMs fitted (on KPN network). Most have roamed onto T-Mobile but a couple have selected AT&T. If we don’t update the LX40 firmware to 4.15 then when AT&T sunset their 3G network will the SIMs be triggered to roam to a new network (assuming one is available)? Or is there a risk they will stay stuck on AT&T with no data connectivity?

2

@david.corder

The LX40 is an LTE cat 1/4 or LTE cat M1/NB1, AT&T sunsetting their 3G service should not affect the devices at all given they do not use 3G. If it works now then there is no specific reason it would stop working post sunset (related to the sunset).

Regards

Matt

3

Hi Matt,

Thanks for the reply. The reason for my question is that is seems that some 4G devices may be affected because they also have legacy 3G support:

image
image605×777 54.1 KB

The ALEOS update to 4.15 that came out at the end of last year addresses this problem. I’m trying to understand whether updating the firmware is essential for all LX40 devices in the US or whether those on roaming SIMS will simply jump to a different network.

4

@david.corder

Ok so the technical explanation (from the module perspective which looks after the comms with the network perspective and is detailed here) is as follows.

  • When the unit attaches to the network it can either do this circuit switched (CS) or packet switched (PS). None had really thought 5 years out when this setting was set that it might be an issue but it turns out it is.
  • A long time ago the default setting of the unit was to do it CS (he 03 and the 10 are quite old units now), all of the newer units have been default PS for a while now.
  • If the units try to attach is a circuit switched fashion the network will reject this as only LTE will be available and LTE is an all IP network.

The Aleos update will just set the unit to attach PS allowing it to complete the registration process.

As to your question will it just roam onto something else, if it is outright reject then yes, if it does not get a response then you might be in a no mans land, I cannot find any documentation on specifically what would happen. I suspect it might go off and find another provider but I don’t know that.

Regards

Matt

1 Like