T-Mobile US expanded into 120 additional cities and announced plans to blanket Puerto Rico with low-band coverage, as deployments of its 600MHz airwaves continued.

Among those to get T-Mobile coverage for the first time were a number of cities in Maine, North Carolina, Pennsylvania and the operator’s home state of Washington. All told, T-Mobile said it has deployed 600MHz spectrum in 910 towns across 32 states.

An operator representative told Mobile World Live T-Mobile wants to add all of Puerto Rico to the list, aiming to deploy island-wide 600MHz coverage later this year. Those airwaves will supplement AWS and PCS spectrum already deployed there.

Additionally, T-Mobile said it will begin enabling carrier aggregation of 600MHz and mid-band spectrum this month, in a move meant to boost speed and capacity.

Device dependent
But the impact of the deployments on user experience will depend on what device users have in hand.

T-Mobile currently offers six compatible Android smartphones, including the Samsung Galaxy S9 and LG V30, but the operator said more than a dozen additional 600MHz-capable handsets are expected to launch this year. Apple, which holds more than a third of smartphone OS market share in the US, did not include 600MHz in its latest iPhone refresh.

Options for customers who want to take advantage of 600MHz carrier aggregation will be further limited in the short term to the LG G7, which will be compatible with the feature out of the box, and the Galaxy S9, which the representative said will receive an upgrade to enable the technology “soon”.

T-Mobile previously said 600MHz will serve as the foundation of its 5G network, providing a broad coverage layer which will be augmented by targeted mid-band and mmWave deployments.