Most mobile phones you buy in South Korea don’t work in Japan, while a phone bought in the United States may or may not work in Europe.

Consumers now face perplexing alphabet soup of terminology and technical talk of radio frequencies when simply seeking to buy a phone to call a business associates or loved ones from anywhere in the world.

The engineers of tomorrow’s mobile technology are hoping to change that.

At a forum Friday sponsored by Samsung Electronics Co. on South Korea’s Jeju island, the architects of tomorrow’s wireless future - referred to as fourth-generation technology - discussed ways to help them meet the challenge of true worldwide mobile roaming.

Finding that unified space everywhere in the world isn’t a simple task, given the clutter now in the air filled with everything from police radios to satellite transmissions.

Studies under way are seeking to determine whether frequencies now in use by other technologies could be shared with new devices that would be able to sense if they are free to transmit.

Another idea to free up frequencies would be to reallocate ones now given to obsolete technology or those that don’t see heavy use.

Agreeing on a single worldwide frequency would also be a key to allowing the new technology to work seamlessly worldwide.

‘’It’s essential this time that the fourth generation, whatever that means, is indeed a global technology,'’ said Alberto Ciarniello, a vice president at Italy’s Telecom Italia.

Consumers shouldn’t have to spend thousands of dollars for devices that can work with various competing technologies to be able to roam worldwide, said Ali Tabassi, a vice president from U.S.-based Sprint Nextel Corp.

But as is often the case with trailblazing technology, a potential format and frequency war is taking shape, along with a debate over how quickly the industry should move.

Some companies are supporting the technology known as Mobile WiMax, a burgeoning standard now coming into use that has been strongly backed by U.S. chipmaker Intel Corp. It offers relatively fast connections over a long range, but not the kind of super-fast speeds that are considered the realm of the fourth-generation future.

‘’We cannot wait for another three to four years for another technology platform to support the Internet-everywhere dream,'’ said Bin Shen, vice president for broadband at Sprint Nextel, which plans WiMax trials by late 2007 before launching the service in the United States in 2008. ‘’We believe Internet is like air and oxygen in people’s lives in the future.'’

South Korea has already launched a limited Mobile WiMax trial and plans to cover the capital, Seoul, with the service by early next year. However, in an indication of the difficulties in deploying a worldwide standard, the Korean system uses a different frequency than the one planned for Sprint Nextel’s future network due to government restrictions.

Samsung has backed WiMax and is a partner in commercializing the technology in South Korea and the U.S.

But at the same time, Samsung at the forum is showing off its version of next-generation mobile technology. The South Korean company is one of several working to develop a standard for lightning-speed data transmission that hasn’t yet been named and won’t be agreed upon until at least 2010, meaning it won’t be in consumers’ pockets for years.

Some say that’s too long to wait.

‘’Why can’t users today connect to the Internet everywhere they are?'’ asked Siavash Alamouti, chief technology officer for Intel’s mobile wireless division. ‘’We’ve got to do it as fast as possible.'’