Was upgraded a YEAR ago. AT&T put LTE in NHV-BOS in a tight line following the NEC just for Amtrak. The giveaway of why they did it is in RI, where I-95 diverges from the NEC by quite a bit, and the LTE follows the NEC, and not I-95. It was incredibly fast, but it sort of bogged down when there was low signal in the area. I was surprised, as I would think that with external antennas mounted high up on the train car, it would have a good signal when my iPhone inside the car was just barely holding on. Hopefully they have AT&T fill in the gaps, and give them space on the ROW if necessary to make it completely seamless.