Singtel fined S$1 million over mobile service disruptions in March that affected 720,000 users

The disruption on Mar 18 was resolved within an hour, Singtel’s CEO Ng Tian Chong 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.