The Finnish and Japanese research programmers have been trialing IMS features over IP networks between Europe and Japan. During the trials the two operators tested voice services over IP as well as instant messaging and a variety of other services.

IMS can form the basis of a whole range of multimedia communication services between mobile phones or fixed line connections.

It allows both mobile devices and landline phone connections to establish IP sessions between each other allowing users to share content files, interactive applications and real time video. Nokia and NEC were also keen to point out that the new Push-to-Talk services much trumpeted by some operators will also work over IMS connections.

Nokia’s Petri Pöyhönen, V-P of Core Networks said "IMS is a vital component of our long-term business strategy and these trials mark an important milestone in bringing this new technology to operators. In the future, we see IP based multimedia becoming mainstream, providing people with a richer means of communications. Earlier this year Nokia announced the availability of end-to-end SIP and IMS. Now these first successful IMS-to-IMS interoperability tests clearly demonstrate the commitment of Nokia and NEC to open standards."

The two companies will also use the tests to look at, if not solve, several issues related to roaming at the service level.