Voice over LTE (News - Alert) (VoLTE) and its cousin, rich communications services (RCS), are slowly making inroads globally.

The latest announcement comes from Tele2 AB in Stockholm, which claims to be the first cellular operator in Europe to test VoLTE over a live network.

Testing on its Swedish network, Tele2 has conducted a fully end-to-end standards compliant test using technology from Mavenir Systems and Nokia Siemens Networks (News - Alert), according to the company.

"We have consciously built in support for VoLTE in the 4G network, covering almost the entire population of Sweden,” said Joachim Horn, CTIO for Tele2. “The tests we have conducted have shown tremendous results in a multi-vendor environment. From a technical standpoint we could be ready to launch commercially within a year.”

Metro PCS led the way for VoLTE in the U.S. last year, and globally the Spanish and Korean markets have been quick to embrace the technology.

Spanish operators have been pioneering RCS in Europe, unveiling interoperable services last year. But VoLTE has been slower to take off in the market, according to an article in Rethink Wireless.

This is because Spanish operators are still expanding their HSPA network, according to the article.

In Korea, meanwhile, three operators have launched RCS platforms that integrate messaging, voice and data services. SKT joined rivals Korea Telecom (News - Alert) and U+ in offering RCS services, according to Rethink Wireless. They have promised to interoperate.

SKT, which came last to the party, is differing from its Korean rivals by planning to charge for some of its RCS features. It recently said that the service will be free for users who purchase its flat-rate 3G or LTE contract before June, but those who enroll after that will pay certain fees based on their plan, according to the Rethink Wireless article.

Video sharing will reportedly cost 0.33 Korean won per second on a flat rate tariff and won 0.6 on a usage-based plan. Messages will be charged at won 20 ($.01) each, and file sharing will count toward data allowances.

This pricing model varies from other VoLTE and RCS adopters in Korea, Spain, Germany and elsewhere, where currently the services are free in an attempt to draw people away from over-the-top services such as Skype (News - Alert).

While LTE is largely used for data services right now, with voice over 2G and 3G, the emergence of VoLTE will bring better call quality, faster connection times and reduced operator cost. When the infrastructure is rolled out, that is.

VoLTE and RCS are critical for cellular providers as the economic model for voice falls apart with the emergence of data connections and the over-the-top VoIP services that ride on its back. With users discovering that they can call for free using Skype and services such as Google Voice, it is becoming increasingly important that operators provide a credible alternative to over-the-top services.