North Korea's sole 3G network operator has managed to double its subscriber base in a little over a year and is about to hit 2 million users.
Koryolink launched service in the final days of 2008 and has become one of the most visible foreign partnership success stories in the country.
The network operator is jointly owned by Egypt's Orascom Telecom Media and Technology Holding (OTMT) and North Korea's Ministry of Posts and Telecommunications. Orascom holds a 75 percent majority stake with the remainder in the hands of the government.
Before Koryolink's service began, mobile phones were an unusual sight in Pyongyang, but that has changed in recent years. Visitors speak of seeing scores of citizens talking and texting from mobile handsets.
The services on offer to users aren't too different from those in other countries -- voice, text and mobile Web. But there is one key difference: Koryolink customers cannot directly place international calls, send text messages overseas or access the Internet through their handsets.
Some users, typically resident foreigners in the country, are permitted to make international calls and were recently permitted Internet access, but their handsets cannot access most domestic phone numbers.
The restrictions are in line with other controls on telecommunications within North Korea. The country remains one of the most closed in the world and most citizens are not permitted to have direct contact with people overseas.
The launch of mobile Internet service for foreigners hit headlines across the world, coming shortly after Google Chairman Eric Schmidt visited the country and called for greater Internet access. Initially seen as a reaction to Schmidt's visit, Koryolink later said the timing was coincidental.
And then a few weeks after launching the service, it was scaled back. It had originally been offered to tourists and resident foreigners, although now is available only to the latter.
Martyn Williams covers mobile telecoms, Silicon Valley and general technology breaking news for The IDG News Service. Follow Martyn on Twitter at @martyn_williams. Martyn's e-mail address is firstname.lastname@example.org