Abstract. The widespread availability of both fixed and wireless network connectivity and the growing market of portable devices are enabling anytime and anywhere impromptu collaboration. The emergence of Mobile Ad-Hoc Networks (MANET) further opens up new possibilities for the provisioning of advanced collaborative services, such as civil protection, e-care, and troop car management. However, the design and the deployment of collaborative applications in MANET scenarios raises new group management challenges. In particular, MANET characteristics, e.g., unpredictable and frequent mobility of users/devices, intermittent device connectivity, continuous variations of network topology, make it impossible any a-priori knowledge about group members availability and ask for novel solutions to handle properly the communication about group members. The paper proposes a context-aware communication model to govern communication on the basis of the characteristics of the communicating parties, suc...