Cellular capable sensors include a pre-provisioned Twilio SIM which the sensors use for initial onboarding and to report power outages. This capability depends on coverage and agreements between Twilio and local carriers. In the United States, the carrier is T-Mobile.
As per this announcement, T-Mobile is shutting down its 2G network April 2nd 2024, but may reduce coverage sooner. T-Mobile has already shut down its 3G network.
The impact is sensor model UX-E4C will no longer be capable of using cellular in the United States.
Sensor models UX-F5C, UX-G5C, UX-G6C are 2G/3G/4G capable and therefore unaffected.
How to determine your sensor model:
There is a PID portion of the sensor serial which indicates the model
KH4 - UX-E4C (2G/3G & 802.11n) (Also sensors with superhero surnames as serials are UX-E4C)
KLR, KLQ - UX-F5C (4G & 802.11ac)
KRY- UX-G5E (802.11ac)
KSN- UX-G5C (4G & 802.11ac)
KYT -UX-G6 (802.11ax)
KYV- UX-G6C (4G & 802.11ax)