Telstra has confirmed repairing an issue that saw its 4G mobile service drop out across Sydney and other parts of New South Wales earlier on Friday morning.
According to a spokesperson at the telecommunications provider, it "very quickly" found and contained what it described as a "slight issue" by 9.19am AEST.
"We have had some customers come through regarding 4G in NSW, no time frame available at present but we are investigating now," Telstra tweeted in response to concerned customers earlier on Friday morning.
"Our billing team would be more than happy to discuss appropriate credits for service downtime," another customer representative tweeted.
Telstra's most recent outage was suffered across fixed-line and mobile services due to a fire at its Chatswood exchange, which caused SMS messages to be delivered to the wrong people, along with an enterprise voice and data outage caused by faulty hardware, which both occurred during February.
Optus similarly suffered a 4G mobile data outage in July that also affected its home broadband customers throughout New South Wales, Victoria, and the Australian Capital Territory for around 55 minutes.
An Optus outage back in March had also impacted Telstra customers, with a network issue affecting text messages being sent between Telstra and Optus customers, with some messages being delayed and others failing to send altogether.
That outage came just days after rival mobile telecommunications provider Vodafone Australia's voice outage, which saw some customers lose voice services for a period of four hours.
Vodafone had attributed its own outage to a fault during scheduled work.
Vodafone experienced a voice outage lasting around three hours back in January, which was caused by an error during planned work on the network; and a seven-hour 4G mobile outage affecting data, voice, and text messages a year ago, which was caused by a router issue.
As of June 30, Telstra had 7.6 million post-paid mobile retail customers, increasing by 169,000 since last year, according to its FY17 financial results report published last month.
Mobile revenue was down by 3.2 percent to AU$10.1 billion, thanks to a decision by the regulator to slash the rate that mobile network operators can charge each other and fixed-line network operators for calls by more than half, from 3.6 cents per minute down to 1.7 cents, and SMS pricing down to 0.03 cents per SMS. The also lost 116,000 prepaid mobile users during the financial year.
Telstra has more than 8,600 mobile towers in total, with its 4G network reaching 99 percent of the Australian population.