Open Research Emulator (CORE) [@core]. The host VMs were each given $2$ virtual CPU cores and $2$ GB of virtual memory from a physical machine with $2.6$ GHz Intel Core i7 and a total of $16$ GB $1600$ MHz DDR3 memory. Two host VMs acted as MECs, between which migration was carried out, and the third host VM acted as a user requiring MEC service. Unless otherwise specified, the bandwidth between MECs was configured as $100$ Mbps with only system-inherited latency and jitter. The connection between each MEC and the user was configured with $100$ Mbps bandwidth, $25$ ms latency, and $5$ ms jitter. These connection specifications are typical for wide-area wired networks and local wireless networks, on which MECs and their users operate. They are much more inferior than network connections in data centers. Migration times were calculated by a migration script at each stage of the migration process. We use *rsync* for incremental file synchronization and the amount of transferred data was measured using Wireshark.

Nested KVM and LXC, which contain running applications, were run inside the two host VMs that mimic MECs. The guest OS of the nested KVM and LXC was Ubuntu 15.10. Note that the 