Design and evaluation of a fog platform supporting device mobility through container migration

The integration between the Internet of Things (IoT) and fog computing can pave the way to a plethora of applications. Fog computing indeed allows IoT devices to offload complex tasks to computing resources, known as fog nodes, that are in their proximity (e.g., at the network edge). Fog proximity enables important advantages, first and foremost low latency. However, IoT device mobility endangers those advantages, as the IoT device gets farther away from the serving fog node. Migrating the fog service among fog nodes, following the device route, permits to maintain proximity and preserve low latency. In this work, we propose an OpenStack-based platform that implements a fog service as a container and migrates the latter to support device mobility. We performed experiments over a real testbed to: (i) evaluate the impact of hardware resources of fog nodes on migration performance; (ii) validate our platform. Results are encouraging, as the average round-trip latency between the mobile device and the fog layer was as low as 10ms and exceeded the maximum value allowed by the considered application (i.e., 20ms) in 1.5% of the experiment duration.