Singtel fined S$1 million over mobile service disruptions in March that affected 720,000 users
The disruptions on Mar 16, Mar 18 and Mar 19 could have been prevented by Singtel and were not due to a cyberattack, IMDA's investigation found.
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SINGAPORE: The Infocomm Media Development Authority (IMDA) has imposed a financial penalty of S$1 million (US$782,000) on Singtel for mobile service disruptions in March.
The disruptions, which occurred on Mar 16, Mar 18 and Mar 19 this year, affected about 720,000 of Singtel’s mobile consumer and business subscribers, IMDA said on Tuesday (Oct 20).
In response to CNA's queries, Singtel's CEO Ng Tian Chong said the telco accepted IMDA's ruling and the S$1 million financial penalty.
"We deeply regret the disruption and the inconvenience caused to our customers," he said.
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The disruption on Mar 16 lasted for about nine hours.
Singtel users started experiencing mobile connectivity issues from about 10.30am, with 4G services restored by around 1.30pm. The telco’s 5G services were progressively restored from 2.45pm but full 5G services were not restored until about 8pm that day.
The disruption on Mar 18 was resolved within an hour, Singtel had said previously.
INVESTIGATION FINDINGS
IMDA’s investigation found that the service disruption on Mar 16 was caused by a chiller system failure at a Singtel exchange.
This caused the mobile network equipment at the exchange to overheat and shut down, IMDA said.
“This resulted from a failure by Singtel’s vendor to follow standard operating procedures to reopen a manual valve controlling water flow after a scheduled maintenance, and the lack of active monitoring by Singtel of its manual valves or water flow to the chiller system,” the authority added.
Investigations by IMDA also found that the disruptions on Mar 18 and Mar 19 arose after 5G mobile traffic was redirected from the affected exchange to another Singtel exchange after the disruption on Mar 16.
“The increased 5G mobile traffic load, coupled with a disabled network packet optimiser and a software bug at the other exchange, resulted in intermittent connectivity for some Singtel subscribers during the evenings on both days,” IMDA said.
The packet optimiser optimises data throughput and latency by routing data packets using the most optimal pathways.
IMDA said its investigation concluded that the incidents were within Singtel’s control to prevent and that they were not due to a cyberattack.
The disruption on Mar 16 could have been prevented if Singtel had implemented robust frameworks, procedures, and systems to better monitor the operations of its chiller system at the affected exchange, it said.
“The service disruptions on Mar 18 and Mar 19 could also have been prevented if Singtel had exercised greater diligence to ensure that the other Exchange was able to handle the increased traffic load that arose from the switchover from the affected exchange,” IMDA said.
In determining Singtel’s financial penalty of S$1 million, IMDA said it took into account the scale and impact of the disruption.
The authority said the impact of the disruptions was “significant” given the number of subscribers affected.
However, IMDA also took into account several other factors, such as Singtel’s full cooperation during the investigations.
The authority also considered the telco’s effort to progressively restore its mobile services for affected subscribers with 4G services restored first, followed by the progressive restoration of 5G services over the duration of the incident.
Lastly, IMDA also took into account the goodwill rebates of S$5 to S$10 that Singtel proactively extended to affected subscribers, with the total payout amounting to about S$8 million for consumer and business subscribers.
Since the disruptions, Singtel has taken necessary remediation measures to prevent the incidents from recurring, IMDA said.
These include enhancing maintenance procedures and monitoring for the chiller system, rectifying the systems in the other exchange and conducting exercises to test how effectively the network can switch traffic elsewhere during a failure.
Mr Ng added that Singtel was using new technologies such as AI to better test its network failover capabilities.
IMDA said it holds telcos, which are key service providers, to a high level of service reliability.
“These service providers are required to plan, design and operate resilient networks, and put in place measures to ensure speedy recovery with minimal inconvenience to end-users in the event of a disruption,” the authority said.
“IMDA will not hesitate to take strong action under the Telecommunications Act, including imposing financial penalties, should any lapses be identified.”
Separately, in December last year, Singtel was also fined S$1 million over a 2024 landline outage that affected half a million users and emergency services.
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