DALLAS -- 5G North America -- Major US carriers are falling in line with the concept of a cut-down version of a 5G radio specification arriving as soon as possible, so that silicon vendors can have an early standard for which to develop chips.

Light Reading reported in September that the 3rd Generation Partnership Project (3GPP) has been working to complete its Non-Standalone-New Radio for December 2017. In his keynote at the 5G North America event in Dallas Tuesday morning, Brian Daley, director of core and government, regulatory standards at AT&T Inc. (NYSE: T), said that he is now expecting the spec to arrive between December 2017 and March 2018. (See 3GPP Plans Early Mobile 5G Spec for December 2017.)

"AT&T is also pushing for a non-standard stand-alone architecture ahead of 5G NR [New Radio]," Daley told the crowd.

The stand-alone specification only uses the 5G radio to provide raw wireless bandwidth. The spec will use LTE to start, end and manage the data sessions.

"The main reason for pushing this is that we're in the midst of doing of doing some trials and we want to make sure some of the learnings from the trials turn up in the specification," Daley said. This means that chip designers get a spec they can start to design silicon to ahead of the initial 5G NR spec. (See 3GPP Wants to Complete Initial 5G Radio Spec in June 2018.)

"We've reached speeds of 15-Gbit/s in tests with Ericsson," Daley said of the trials so far. The operator is running indoor and outdoor, fixed wireless and mobile tests, with a "friendly fixed user trial" expected for the end of this year. (See AT&T to Start 5G 'Friendly' Trial by 2016 End.)

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Verizon Communications Inc. (NYSE: VZ)'s director of corporate strategy and development, Alexander Khalin, agreed with his AT&T counterpart in a later panel session about the need for bumping up the 5G spec ahead of its summer 2018 .

"There are carriers that are moving that up," he said, adding that solid specs are needed, so that "the silicon designers can get going."

Verizon, of course, is working on its own fixed wireless 5G specification that should arrive ahead of the 3GPP offering.

The carriers and vendors to whom I've spoken will pay lip service to flowing separate early technical work into the eventual 3GPP uber 5G radio specification. How much fragmentation becomes a factor along the way, however, remains to be seen.

— Dan Jones, Mobile Editor, Light Reading