‘Sivaram’s phone still ringing, but where?’
[TamilNet, Sunday, 08 May 2005, 13:44 GMT]
More than a week after he was abducted and murdered, the mobile phone of one of Sri Lanka’s best known political columnists continues to ring, weekend press reports said. And despite the technology which can allow law enforcement agencies to pinpoint a cellular phone’s location using its relative proximity to local base stations, Sri Lanka’s police claim they have no idea where Mr. Sivaram’s phone might be.
In an article titled “Sivaram's phone still rings, but where?” the Sunday Times reported “more than a week after his death, Mr. Sivaram's phone still rings when dialled. [Colombo Crime Division Director SSP Sarath Lugoda] said Police cannot track its location unless someone answered the phone.”
“Police believe the mobile phone might be in the possession of those who killed Mr. Sivaram,” the paper said.
The Sunday Leader newspaper said this week “[Sivaram’s phone] was off and silent on 29th and 30th [April]. It was on, ringing on May 1st. It was off again on May 2nd and 3rd. It was on again on May 4th and 5th.”
Contrary to rumours that Mr Sivaram’s abductors had replaced his answering greeting with Sinhala ‘baila’ music on his phone, the sample is in fact a hit song in Rajnikanth's latest movie, Chandramuhi, which colleagues of the murdered columnist recognise.
Although police claim they are unable to ascertain the physical location of the phone, mobile service providers have the technology to do so within limits.
When a phone is switched on, and every few minutes when working, it sends out a signal - which can be heard, for example, on nearby sound equipment as a sequence of interference.
All base stations of that network within range respond, and algorithms within a central base-station controller allocates the phone to one base station. This is usually the nearest, unless severe congestion compels the firm to select a more distant station.
|Approximate location deduced from multiple base stations can be improved with signal-strength and timedelay techniques
Whilst this will give an approximate area location, phone firms have another long-standing technique which uses time-delays and strengths of radio signals between a transmitter and at least two base stations to calculate the user's position.
“Finding the caller is a matter of calculating the call's line of bearing,” says Douglas Graham, a technology writer based in Columbia, Missouri, USA.
“Theoretically, the caller will be found at the intersection of the two lines of the angle of arrival. In military terms, this technique is also known as direction finding (DF).”
“[Alternatively] callers are found by measuring the time required for the [call] to be transacted. When time is translated to distance it becomes possible to trace the call to its source.”
Even if the cellular phone is subsequently switched off, the routing details (which base stations, etc) of all incoming and outgoing calls are maintained by mobile phone service providers for some time – which has, in some countries, been legally extended as part of the counter-terrorism measures.
Amidst accusations that Sri Lanka’s security services are implicated in Mr. Sivaram’s killing, newspaper reports of the apparent indifference of the country’s Army Chief to reports of Mr. Sivaram’s abduction is fuelling speculation of top-level complicity.
Shortly after Mr. Sivaram, one of Sri Lanka’s leading military analysts (who wrote under the nom de plume ‘Taraki’), was abducted, fellow senior journalist Rajpal Abeynayake, called up Army chief Shantha Kottegoda for help, but the Commander was nonchalantly unconcerned.
“'Rajpal, you should immediately inform the police so the gang will not make a getaway,” the Army Commander had advised the frantic reporter.
“He seemed not to immediately recall who Sivaram was,” Abeynayake wrote in the Sunday Times on May 1. “He promised to do what needs to be done, and said he will inform Army Intelligence of the matter.”
Yet when the reporter called Kottegoda after the discovery of Mr. Sivaram dumped body, the General “recalled that he was a keen reader of the deceased Sivaram's reports and analysis,” Abeynayake wrote.
Condemning the murder, the LTTE’s political wing pointed out that Mr. Sivaram had been threatened by Sri Lanka military intelligence several times in the past.
“The Security forces have forced entry and have searched his residence in the past. Murder was carried out inside the high security zone. Therefore, the Sri Lanka Government and its security forces bear responsibility for this murder,” the LTTE said last week.