Mobile edge computing (MEC) systems (in which intensive computation and data storage tasks are performed locally, due to absence of communication infrastructure for connectivity to cloud) are currently being developed for disaster response applications and for tactical environments. MEC applications for these scenarios generate and process significant mission critical and personal data that require resilient and secure storage and sharing. In this paper we present the design, implementation and evaluation of R-Drive, a resilient data storage and sharing framework for disaster response and tactical MEC applications. R-Drive employs erasure coding and data encryption, ensuring resilient and secure data storage against device failure. R-Drive adaptively chooses erasure coding parameters to ensure highest data availability with minimal storage cost. R-Drive's distributed directory service provides a resilient and secure namespace for files with rigorous access control management. R-Drive leverages opportunistic networking, allowing data storage and sharing in mobile and loosely connected edge computing environments. We implemented R-Drive on Android, integrated it with existing MEC applications. Performance evaluation results show that R-Drive enables resilient and secure data storage and sharing.

Mobile Edge Computing (MEC) has been gaining significant interest from first responders and tactical teams, primarily because they can employ handheld mobile devices to form a computing cluster (for computing tasks like face/scene recognition, virtual assistance) when connectivity to the cloud is not present or it is limited. High user mobility in first responder or tactical environments makes MEC challenging, as wireless links observe substantial fluctuations. Typical cloud-based coordination (e.g., ZooKeeper-based service discovery and coordination, device naming, security) needed by edge computing tasks cannot work in these environments. Driven by the need for a resilient and lightweight coordination service, in this paper, we design and implement Edge-Keeperto provide cloud-like coordination for MEC systems. It provides naming, network management, application coordination, and security to distributed edge computing applications. It maintains an edge cluster among devices and intelligently stores its data on a group of replicas to guard against node failure and disconnections. We provide a full-system implementation of EdgeKeeper for Android and Linux platforms. We have integrated EdgeKeeper with existing MEC applications and performed real-world performance evaluations in a wide-area search and rescue operation conducted by first responders, which proves it to be lightweight and suitable for mobile devices.