Orange continues to advance HD Voice, and has for the first time made it possible to make calls between two countries.
Orange subscribers in Romania and Moldova are now able to make calls between the two countries using HD Voice. Orange has been able to interconnect its two mobile networks and still ensure end-to-end improved voice quality from one country to the other, the operator said.
The improved quality HD Voice offers is possible thanks to the use of AMR-WB (Adaptive Multi-Rate - Wideband), a speech-compression algorithm that doubles the range of voice frequencies transmitted (50 to 7000Hz versus 300 to 3400Hz). Both caller and receiver have to use a phone that has AMR-WB turned on.
Orange didn't need any new equipment, but had to work on getting the network configuration right, according to Alex Nourouzi, the company's director of product marketing.
For an HD Voice call to be possible between two countries, the network interface that connects them has to be either IP or BICC (Bearer Independent Call Control).
The setup would also work between two operators in the same country, Nourouzi said.
Moldova, which is located between Romania and the Ukraine in Eastern Europe, holds a special place in HD Voice lore since it was the first country in the world to get HD Voice, when Orange launched a service in 2009.
Today, Orange offers HD Voice in 14 countries, and almost 4 million subscribers have started using the technology, compared to 1 million subscribers a year ago, the operator said.
To keep up the momentum it is important that all smartphones come with the technology turned on by default, which isn't the case today, according to Nourouzi. That Apple has done so on the iPhone 5 is an important step, he said.
At the end of August, 45 HD Voice service launches had taken place across the world, according to industry organization GSA (Global mobile Suppliers Association).