MOBILE phones were described as "lethal in the extreme" by Judge John Neilan during a sitting, of the Tuam District Court on Wednesday. His comment followed the disclosure in court that, someone had gained access to hiss exdirectory telephone number. Threatening calls had been made, he said, and access to his number may have been made via a mobile telephone.
He also said he believed that a mobile telephone was used to track down journalist Veronica Guerin. "If these mobile phones were not available, perhaps Ms Guerin would be alive today," he said.
His comments raise two issues related to the use of mobile telephones:
. can their use provide, information about a user's location?
. do they provide special access to exdirectory numbers?
Both types of mobile phones in common use here can provide limited information about where a user is when the phone is used, but this would only be available to the company that operates the mobile phone network, according to Ms Brenda Moriarty, head of marketing at Eircell.
Conversations using, analogue "088" phones can be listened to if, a person has an appropriate radio receiver, but an eavesdropper would not have a location for the telephone user. The digital "087" phones automatically "encrypt" or code the voice message so it, cannot be understood if intercepted, nor would information about location be available.
Details on location are available to the network when a mobile is, used, however, Ms Moriarty said. The system takes note of the mobile antenna - which services a "cell" which could be from a few hundred yards up to 30 miles across - contacted by the telephone handset. The information," is used for accurate billing, she said.
An 087 phone also automatically provides information about its nearest cell even when no conversation takes place. These phones emit a periodic signal which lets the mobile system know where it is, whether at home or abroad.
Such location information was used in a recent UK court case in which the police were able to demonstrate a mobile phone user was not where he claimed to be at a given time.
A person's exact location within a mobile phone cell is not available, however. It would be difficult or impossible to find a person within a cell because it can cover an extensive area.
Telecom Eireann and Eircell both insist that mobiles do not provide special access to ex directory numbers. "We have strict controls on our ex directory numbers," a spokesman for Telecom said.
Directory inquiries and general operators do not have direct access to these numbers, according to telecommunications sources. In extreme circumstances supervisors can refer requests for access on to the ex directory customer, but no number would be given out to a caller, the source said.
This is true no matter what type of phone the caller used to reach the operator. It is unclear, therefore, how the person who phoned, the judge managed to get his number. Telecom, the spokesman said was assisting gardai in relation to the nuisance calls to Judge Neilan.
