Wireless networks enable mobility, multihoming, and Delay Tolerant Networks. In such networking environments, the principles of the Internet, i.e., the end-to-end principle and the combination of identity and location in IP addresses, cannot be applied. In this paper, we propose a scalable application centric approach for supporting mobility, multihoming, and interconnecting highly heterogeneous networks where the networks may belong to different networking paradigms, e.g., IP based and Delay Tolerant Networks. Applications and users that want to communicate, use communities. These communities are application specific overlays formed by entities (nodes or other communities) that want to support the application. Community members might together have several network technologies available, and the community manages internetworking information for the members to seamlessly integrate them. This integration is assisted by a community support layer that coordinates the communities with the available networks. An underlay layer common interface is used to access the different networks, allowing an implementation that considers its specific characteristics and challenges. We propose a global cryptographic based namespace for entities to enable internetworking across heterogeneous networks with different locator schemes. Identifiers are resolved to locators using a late binding approach. Furthermore, we analyse the communication challenges present in emergency and rescue operations and describe how to deal with them using our proposal.