Japan’s second largest mobile operator KDDI and Sweden-based telecoms equipment vendor Ericsson agreed to conduct pre-standard 5G trials on the 4.5GHz frequency band in a number of cities across Japan.

Ericsson said in a statement the proof of concept trials will involve a large number of tests across a wide range of 5G use cases on the 4.5GHz and 28GHz frequency bands, including interworking between 5G and LTE.

The equipment vendor announced a similar agreement with Japan’s third largest operator SoftBank at the end of August.

Yoshiaki Uchida, KDDI’s senior managing executive officer, said: “Our collaborative partnership with Ericsson strongly supports KDDI’s objective to launch commercial 5G services for our subscribers and enterprise customers by 2020.”

Chris Houghton, Ericsson’s head of North East Asia, said: “5G is an evolution of LTE and by using the 4.5GHz frequency band, we will be able to further develop our features and optimise the interworking between 5G and LTE.”

The 4.5GHz band is one of the candidates for 5G in Japan, and the agreement is an extension of a previously announced 5G R&D collaboration between Ericsson and KDDI.

Mobile standards body 3GPP is expected to finalise the first set of 5G specs by March 2018.

From January 2017, the two companies have carried out proof of concept activities using 28GHz band in Shinjuku, one of the busiest districts in Tokyo.