Method for building a multimodal business channel between users, service providers and network operators. The service provided to the users is personalized with a user's profile derived from language and speech models delivered by a speech recognition system. The language and speech models are synchronized with user dependent language models stored in a central platform made accessible to various value added service providers. They may also be copied into various devices of the user. Natural language processing algorithms may be used for extracting topics from user's dialogues.