US operators AT&T and T-Mobile both talked-up their efforts around LTE Licensed Assisted Access (LTE-LAA) technology, with the smaller player trumpeting higher speeds in its pilots than its rival.

LTE-LAA combines licensed 4G spectrum with unlicensed frequencies in the 5GHz band to deliver higher speeds. It is designed to co-exist with other 5GHz technologies including Wi-Fi, using a “listen before talk” feature to ensure fair use.

AT&T partnered with Ericsson in what was called “one of the first-ever live LTE-LAA field trials”, achieving speeds of more than 650Mb/s in downtown San Francisco. The company said the technology forms part of its “5G Evolution” plans, designed to offer “state-of-the-art 5G speeds as early as late 2018”.

“As demand continues to grow at a rapid pace on our network, being able to offer customers not only fast speeds, but also increased capacity by combining licensed and unlicensed spectrum is an important milestone,” said Marachel Knight, SVP of wireless network architecture and design at AT&T.

T-Mobile US said its field tests in Los Angeles “showed blazing 741Mb/s download speeds”. It said the technology is “live in select locations” across the US, with more rolling out later this year.

“While our competitors scramble to deal with the way unlimited data plans are slowing down their networks, we’re already moving on to what’s next. This means that the fastest LTE network – that’s T-Mobile – will only get faster,” said Neville Ray, CTO.