The unlikely story of advanced 3G cellular service in the world's most tightly controlled and secretive country has turned another chapter with the start of network trials.

Cellular carrier Orascom said on Monday that it has completed the first 3G call on a WCDMA (Wideband Code Division Multiple Access) trial network in North Korea, and is working towards a commercial launch there later this year.

Orascom, based in Egypt, said in January that a 25-year exclusive license to offer 3G cellular service in the country had been awarded to CHEO Technology, a joint venture in which Orascom holds a 75 percent stake and Korea Post and Telecommunications holds the remaining 25 percent.

A full commercial service is scheduled to begin in the second half of the year, Orascom said.

In January, Orascom said it intended to provide voice, data and value-added services across the network, which represents a $400 million investment.

North Korea, the world's only Communist dynasty, keeps tight control of its people. Almost all citizens are forbidden from leaving the country and there are controls on internal movement of people into the capital city of Pyongyang. Poor conditions in the country have prompted hundreds of thousands over the last decade to risk their lives and flee to neighboring China.

Almost total government control of the population means phone calls are restricted and subject to routine monitoring, according to humanitarian aid groups that monitor North Korea.

A GSM (Global System for Mobile Communications) cell phone network was previously launched in the country but access was restricted in 2004 and it's now thought to be used by a handful of elite in the country.