Neville Ray said in a blog post that mmWave, which Verizon and AT&T have concentrated on in delivering their solutions, would not benefit many people as it would not travel very far.
"Our 5G goal is not headlines or buzz or bragging rights," Ray wrote. "No, we're going to do this right... when it's ready for our customers. And in a way that allows us to bring the benefits of 5G to the whole country."
He criticised Verizon's launch of a 5G service in Minneapolis and Chicago, saying: "They claimed their second 5G 'first', essentially acknowledging that their first 5G 'first' with made-up 5G (W)TF technology last year was not, in fact, a 5G first of any kind.
T-Mobile is waiting on a merger with the US' fourth provider, Sprint, to be approved by US authorities and, according to industry publication Fierce Wireless, its "5G for all" mantra will need the merger to work as Sprint has planned its 5G solutions around mid-band spectrum. Compared to Verizon and AT&T, T-Mobile has a comparatively smaller number of mmWave spectrum licences.
"Verizon’s mmWave-only 5G plan is only for the few. And it will never reach rural America. Meanwhile, AT&T has rolled out a '5GE' icon to customers phones to dupe them into thinking their same-old 4G LTE service is something new and different (spoiler alert: it’s not)," Ray wrote.
He said mmWave had great potential as far as speed and capacity went, "but it doesn’t travel far from the cell site and doesn’t penetrate materials at all. It will never materially scale beyond small pockets of 5G hotspots in dense urban environments".
T-Mobile chief executive John Legere and Sprint executive chairman met the Federal Communications Commissioner Jessica Rosenworcel last week to push for the US$26 billion merger to be approved. A decision on the merger is expected by June.