Telco M1 will be offering its mobile customers free local mobile calls, as well as local text messaging and multimedia messaging services this Sunday, to compensate for a mobile service outage on Tuesday morning.
In a statement issued yesterday evening, the telco said the cause of the disruption was a software issue.
M1 said it had sought to restore services quickly. But the complexity of its network meant that it had to check and test many interlinked network components individually to ensure services could be effectively restored.
"M1 has recently made significant investments to upgrade our mobile network by incorporating several new network entities and advanced software features. This has increased the complexity of the mobile network," a spokesman explained.
M1 mobile subscribers had intermittent access to voice, text messaging and data services from 7am to 12.15pm.
The incident on Tuesday follows an outage of up to 71 hours on M1's mobile networks in January last year, as well as other mobile disruptions.
The Infocomm Development Authority of Singapore (IDA) said on Tuesday evening in a Facebook post that it was "concerned with (Tuesday's) outage, taking into consideration other outages that happened to M1 in the past year".
The IDA has ordered M1 to carry out a thorough investigation on the cause of the outage as services were disrupted for about six hours, inconveniencing many mobile users.
The telecoms regulator said it would carry out its own investigations and urged M1 to give regular updates and help users who may still have service difficulties.