Virtualization is a promising approach to meet the objectives of next generation networks. It will enable building pervasive systems, with the possibilities of automated adaptation and provision of personalized services for users with different needs and contexts. In this paper, we propose the use of Avatars: software delegates to hide heterogeneity between entities such as networks, users, services and any resource or device. Avatars act at an abstraction overlay level, on behalf of their represented entities. They carry information and intelligence (workflows) and cooperate to make decisions like the reconfiguration of the entity they stand for. A software agents-based implementation is then proposed and evaluated.