SINGAPORE — The hunt for the source of interfering signals that have repeatedly disrupted train services on the Circle Line (CCL) in recent months was ratcheted up a notch on Friday (Nov 4), with the authorities taking the unprecedented step of ordering a full-day suspension of mobile services through all 30 stations.
Experts TODAY spoke to generally did not want to speculate on why mobile services had to be suspended across the entire line — the mobile network will be restored progressively from 11am on Saturday.
But Professor Lim Teng Joon, a wireless-communications expert at the National University of Singapore said: “The fact is we don’t have enough information … but (based on the scale of the shutdown) it sounds to me that they’re still quite far from the answer unless they have some kind of strategy that they’re not telling us about.”
The first mobile-service suspension on the CCL was in September and lasted for two hours at four stations. On the second and most recent time — on Thursday, a day after train delays hit various locations on the CCL — it extended to the whole line, but for about two hours.
Friday’s shutdown was to have lasted two hours or so, according to the first announcement just after 7am. SMRT warned of delays on the CCL owing to the recurring signal fault but trains appeared to run smoothly at several stations TODAY visited.
Later in the morning, however, the suspension of mobile services was extended to the whole day, with the Land Transport Authority (LTA) citing “ongoing tests”. An Infocomm Media Development Authority spokesperson said it asked Singtel, StarHub and M1 to kill their networks on the CCL on Friday “to allow the LTA and its contractors to undertake a rigorous process of elimination so that all possible causes can be isolated and investigated fully”.
The shutdown of mobile services — the second in successive days — had irked commuters, who got no notifications that calls, SMSes and Internet access would be cut.
The LTA was unable to say on Friday if mobile services would be turned off on the CCL over the weekend. A spokesperson told TODAY: “We will appreciate if you could let us complete our investigations first before we can provide an update on the issue.” Signalling that commuters could face mobile service blackouts on their CCL journeys again, the LTA said on Facebook: “Should there be a need to extend this further, affected commuters will be informed as early as we can.”
Prof Lim said the shutdowns could be to eliminate the possibility that mobile signals were to blame for disrupting signals between trains and tracks. “If every time you turn off the cellphone signals (and) the whole system runs perfectly, then it becomes more likely that (the interference) is deliberate.”
Railway signalling, control and communications lecturer Andrew Ng from the Singapore Institute of Technology said that by ruling out mobile-signal interference, the authorities could then evaluate the strength of wireless-communications signals between trains and tracks.
“At the same time, it allows them to assess the performance of the signal transmission media and equipment, which include the cables, the transmitters and the antennae,” he added.
Asked about the impact of the shutdowns on the telcos, Mr Clement Teo from technology consultancy Ovum said they would have built in some buffer in their financial calculations for situations such as outages. But a prolonged shutdown may dent their bottomlines, he noted.
Agreeing, Mr Shiv Putcha, consumer mobility and telecommunications associate director with IDC Asia-Pacific, said: “There will likely be much more impact on the mobile-data side given the typical consumer behaviour in a commuting scenario.”
Lawyers said that the telcos, as licensees, had an obligation to comply with such requests by the authorities. Still, there may be room for legal recourse if a third party was involved.
“If the investigations show that there was third-party intervention and such intervention was an abuse of the telcos’ infrastructure, then the telcos may consider, at that point, to pursue legal action against such third parties,” said Mr Rajesh Sreenivasan, head of law firm Rajah & Tann Singapore’s technology, media and telecommunications practice. ADDITIONAL REPORTING BY WONG PEI TING
