Singtel Optus and the National Broadband Network Co will be excluded from the metropolitan auctions for the coveted 5G spectrum, because both are above newly introduced government limits for telecommunications companies.

Buying access to the 3.6GHz band of the radio-wave spectrum is crucial for telcos keen to roll out next generation fast-speed 5G mobile networks.

The NBN Co, along with Optus, will not be bidding in metropolitan auctions for spectrum. Credit:Peter Braig

However, telcos have been capped at 60MHz in metropolitan areas and 80MHz in regional areas, in a bid from Communications Minister Mitch Fifield to “promote competition ... while ensuring this scarce spectrum is put to its highest-value use”.

The new limits mean telcos with current spectrum holdings in the 5G-suitable band of 3400 to 3700MHz will either only be able to bid for some spectrum or not be able to bid at all.