SINGAPORE — Before 3G services crashed for three days for many M1 subscribers last week, the telco was already working to improve its network resilience, beginning in the second half of 2011.

The work is slated to be finished by the middle of this year, said M1, which yesterday released more details on the service disruption that took place from Jan 15 to Jan 17.

The telco said that, without its contingency plan, it would have taken about three to four months to restore its network service.

M1 said in a statement: “As a result (of activating the contingency plan), we were able to restore service in the shortest possible time under the circumstances”.

To do that, M1 increased network capacity and signalling links between all the other mobile network switches.

This involved, among other things, reconfiguring 416 base stations to an alternative network switch, followed by testing, which included test drives to the coverage area of each base station to ensure that there was full call continuity for both voice and data services.

M1 also shed more light on the incident that had caused the widespread disruption. It said the problems started during upgrading work by a vendor on the backhaul transmission network at one of its network centres.

At around 2.30am on Jan 15, sparks were set off when the vendor was trying to connect the power cables from the transmission equipment rack to the distribution rack.

This caused smoke to be emitted from the racks, which in turn triggered the FM 200 gas suppression system that led to a gas discharge. This set off a water sprinkler, causing damage to one of the mobile network switches.

Speaking to the press yesterday, M1 CEO Karen Kooi Lee Wah said the telco would “work very hard” to win back customer confidence.

It has offered all postpaid customers three days of free local mobile calls, SMS, MMS and data services during Chinese New Year, between Feb 10 and Feb 12. Prepaid customers will get a S$1 bonus for every top-up of S$17 and above next month.

Ms Kooi said: “We are offering the three-day free usage to our entire base, not just for people who were impacted. And we certainly hope this will help soothe ruffled feathers.

“We hope customers will continue to support us and we will work doubly hard to win back their trust,” she said. Peter Yeo