Telecoms firm eir is rolling out its 5G network across 10 cities and towns around Ireland.
It will begin with 100 5G sites across Dublin, Cork, Limerick, Galway and Waterford - as well as Carlow, Castlebar, Dundalk, Drogheda and Kilkenny.
The company says it will allow customers to enjoy "unrivalled speed and reliability" that 5G offers.
It will see peak speeds over 1Gbps.
Another 100 sites will also be launched in the coming weeks - bringing coverage to Athlone, Bray, Ennis, Letterkenny, Sligo, Tralee and Trim in time for Christmas.
A further 100 sites will be added early in the new year, bringing the total number of towns and cities with eir 5G coverage up to 20.
Eir says it will continue to invest heavily throughout 2020, with plans to roll out 5G coverage to every major town in Ireland.
It is launching 5G services with a range of devices and plans with 'No Limits Data' for €49.99 for eir broadband customers.
The service is available to eir customers on a range of 5G devices - including the Samsung A90 5G, the Samsung S10 5G, the Samsung Note 10+ 5G and the Huawei Mate 20X 5G.
Eir CEO Carolan Lennon said: "I am delighted to launch eir's 5G network, giving our customers widespread access to the next generation of mobile connectivity.
"With 5G, our customers will be able to download their favourite shows instantly, to stream high definition content without buffering and to enjoy lag-free low-latency gaming.
"Most significantly, it will substantially enhance business connectivity and we are proud to play our part in creating the strong telecoms infrastructure that is vital to Ireland's continued growth."
It comes just moths after Vodafone announced it was launching commercial 5G in Ireland.
Vodafone became the first mobile operator to introduce a 5G network - which went live in Dublin, Cork, Limerick, Galway and Waterford in August.