LTE-M(CAT-M1) bandwidth in T-Mobile

drnewcomb and formercanuck are partially correct, but don’t answer the orginal question.

• Cat-M1 uses 1.4MHz channel bandwidth, fixed in the 3GPP spec
• Not every LTE band a carrier offers can use Cat-M1, as carriers only use a specific subset of their LTE bands for use with this AT (Access Technology).  Por ejemplo:
  • AT&T publicly documents it uses these LTE bands: 2, 4, 5, 12, 14, 17, 29, 30, 66 and the LTE-M bands supported are only 2, 4, 12

I'm on the phone with T-Mobile support now to get some truth about which LTE-M bands are in use in North America.  They have responded that they only have this map available to spot check a specific address...which doesn’t answer the much desired question, but does show if you expand the details that band 12 is used for LTE-M (Cat-M1). 

It’s common that a carrier will only use a single band and that single band be a low frequency band so the IoT device has the best chance possible to reach home out of difficult cellular situations.