Cyber-foraging is a technique for dynamically augmenting the computing power of resource-limited mobile devices by opportunistically exploiting nearby fixed computing infrastructure. Cloudlet-based cyber-foraging relies on discoverable, generic, forward-deployed servers located in single-hop proximity of mobile devices. In particular, we define tactical cloudlets as the infrastructure to support computation offload and data staging at the tactical edge. However, the characteristics of tactical environments, such as dynamic context, limited computing resources, disconnected-intermittent-limited (DIL) network connectivity, and high levels of stress pose a challenge for the continued operations of mobile systems that leverage cloudlets in tactical environments. This paper presents an architecture and experimental results that demonstrate that cyber-foraging using tactical cloudlets increases the survivability of mobile systems, defined as the capability of a system to be able to continue functioning in spite of adversity.

Soldiers and front-line personnel operating in tactical environments increasingly make use of handheld devices to help with tasks such as face recognition, language translation, decision-making, and mission planning. These resource constrained edge environments are characterized by dynamic context, limited computing resources, high levels of stress, and intermittent network connectivity. Cyber-foraging is the leverage of external resource-rich surrogates to augment the capabilities of resource-limited devices. In cloudlet-based cyber-foraging, resource-intensive computation and data is offloaded to cloudlets. Forward-deployed, discoverable, virtual-machine-based tactical cloudlets can be hosted on vehicles or other platforms to provide infrastructure to offload computation, provide forward data staging for a mission, perform data filtering to remove unnecessary data from streams intended for dismounted users, and serve as collection points for data heading for enterprise repositories. This paper describes tactical cloudlets and presents experimentation results for five different cloudlet provisioning mechanisms. The goal is to demonstrate that cyber-foraging in tactical environments is possible by moving cloud computing concepts and technologies closer to the edge so that tactical cloudlets, even if disconnected from the enterprise, can provide capabilities that can lead to enhanced situational awareness and decision making at the edge.

Mobile applications are increasingly used by first responders, medics, researchers and other people in the field support of their missions and tasks. These environments have very limited connectivity and computing resources. Cloudlet-based cyber-foraging is a method of opportunistically discovering nearby resource-rich nodes that can increase the computing power of mobile devices and enhance the mobile applications running on them. In this paper we present On-Demand VM Provisioning, a mechanism for provisioning cloudlets at runtime by leveraging the advantages of enterprise provisioning tools commonly used to maintain configurations in enterprise environments. We present details of a prototype for On-Demand VM Provisioning and the results of a quantitative and qualitative evaluation of the prototype compared to other cloudlet provisioning mechanisms. The evaluation shows that On-Demand VM Provisioning shows promise in terms of flexibility, energy consumption, maintainability and leverage of cloud computing best practices, but can be challenging in disconnected environments, especially for complex applications with many dependencies.

Soldiers, first responders and other personnel operating at the tactical edge increasingly make use of mobile devices to help with tasks such as face recognition, language translation, decision-making and mission planning. Tactical-edge environments are characterized by limited resources, dynamic context, high stress and poor connectivity. This paper focuses on three architecture patterns that address these conditions. The Data Source Integration pattern uses server-side standardized definitions of live or cached geo-located data feeds that can be customized and filtered on a single, map-based user interface on a mobile device. The Group Context Awareness pattern uses context obtained from groups of handheld devices operating as part of a team to make sure that the right information is displayed to the right soldier at the right time. The Cloudlet-Based Cyber-Foraging pattern uses cloudlets as code-offload elements to optimize resources and increase computation power of mobile devices. Cloudlets are discoverable, localized, stateless servers running one or more virtual machines on which users can offload resource-intensive computations from their mobile devices. Prototype applications have been implemented for each of these patterns. Experiment results and participation in exercises have shown the effectiveness of the patterns in addressing the challenges of resource-constrained environments.