Thousands of O2 customers in the east of Ireland were without a service this morning because of a hardware fault.
O2 said that a fault on a mast on Three Rock mountain in Dublin was fixed at lunchtime.
Customers in the south Dublin and Wicklow areas experienced a disruption to coverage.
The company said efforts to rectify the fault were hampered by strong winds at the site of the mast, which posed a health and safety risk.
