It used to be a dream for us to speak in our own language on the phone with any people who may not understand our language. The dream seems to be becoming real at least between Japanese and English on a mobile phone network. The accuracy of the simultaneous interpretation is reportedly not perfect yet, but that'd be OK as far as the accuracy is in a reasonable range. For the time being, the text messages simultaneously displayed on the phone screens in the both languages will help to avoid potential misunderstanding which might be caused by inaccurate interpretations. If bandwidth allows to accommodate this simultaneous interpretation and video phone capability, it'd be more helpful.
Source: DiginfoTV via YouTube