BARCELONA -- GSMA Mobile World Congress -- T-Mobile International AG announced today that it will launch commercial femtocell services in Germany in the middle of this year.

The operator has tested the home base stations with T-Mobile employees in Germany, Poland, and the U.K., and has determined that the technology is ready for commercial services, but only on a limited scale. (See T-Mobile Trials Femtos and T-Mobile Backs Femto Chip Startup.)

"In the middle of this year, we will start to roll out [femtocells] in a very controlled way in Germany," said Bernhard Scholl, head of T-Mobile's coverage and transmission solution design and 2G LTE design. "We can provide this functionality for some certain customers. [The femtocell] won't be sold in shops and will be really controlled by us."

T-Mobile will limit the rollout of femtocells this year because there are a number of technical problems that still need to be resolved to make the devices viable for the mass market.

"Femtocells will impact the overall network quality. It's a matter of fact," said Scholl. "If you have a real-world, large deployment, we would prefer to go with Release 8 [devices]. Release 8 will have some significant improvements for mass market deployments."

Scholl told Unstrung that he expects Release-8-compliant femtocells to be available sometime in 2010.

T-Mobile tested femtocells from three different suppliers with 100 employees in Germany, about 90 employees in Poland, and about 60 employees in the U.K. The trial in the U.K. is still going on and will probably involve up to 100 participants, according to Scholl.

Some of the problems Scholl and his team discovered included: limited mobile data rates due to the limitations of slower DSL broadband connections; issues with femtocell location detection; reduced battery standby time in terminals; and interference between the macro cell and femtocell.

But Scholl said these issues are not show stoppers. "There is no blocking factor. Femtocell deployment is possible."

Location detection is a potential problem for operators because they need a way to prevent users from taking their femtocells abroad and using them in another country for cheaper international calls.

"For a real mass market, I'm still afraid we need to have additional solutions here," said Scholl, explaining that he does not consider using GPS an option.

Scholl said T-Mobile has tested femtocell equipment from a different supplier in each country, but he would not divulge the names of those vendors.

For the commercial launch, T-Mobile will deploy standalone femtocells for improving indoor coverage.

— Michelle Donegan, European Editor, Unstrung