Its already here... shhhh...its sleeping.
Optus has already publically announced that they will launch a fixed wireless version in Brisbane & Canberra from January 2019.
Other capital cities to follow, with regional quite some time after that as they have to wait for spectrum licenses to become available.
Would expect a few new plans, aimed at moving people off NBN and onto Optus 5g.
Personally I'm pretty cynical on 5G. Its backed by years of concerted hype (and investment) but still precious little to show for it and very little confirmation about how issues like in building reception and limited dstance are being handled.
My thinking is that Telcos will continue to optimise the 4G service which has some room to improve.
5G will be released inner city and Telco plans won't alter much. You'll still be asked to pay $40 - $120 for a connection. You'll get more data and some more speed but its not going to be revolutionary (for phone plans) only evolutionary.
But the big Telcos (including Optus) have got something they call 5G slated for launch next year so I guess we'll all just wait and see.
Availability - Brisbane & Canberra were the launch cities indicated.
Just like when 4g launched - it will start near the cbd and work its way outward.
News releases did say January 2019, so anytime from now on.
First lot will be trials and will only be Fixed Wireless e.g. you have an Optus Technician come to your place and install equipment to provide the service.
We are quite a way off on portable 5g services.