Mobile micro-cloud is an emerging technology in
distributed computing, which is aimed at providing seamless
computing/data access to the edge of the network when a
centralized service may suffer from poor connectivity and long
latency. Different from the traditional cloud, a mobile micro-cloud
is smaller and deployed closer to users, typically attached to a
cellular basestation or wireless network access point. Due to the
relatively small coverage area of each basestation or access point,
when a user moves across areas covered by different basestations
or access points which are attached to different micro-clouds,
issues of service performance and service migration become
important. In this paper, we consider such migration issues. We
model the general problem as a Markov decision process (MDP),
and show that, in the special case where the mobile user follows
a one-dimensional asymmetric random walk mobility model, the
optimal policy for service migration is a threshold policy. We
obtain the analytical solution for the cost resulting from arbitrary
thresholds, and then propose an algorithm for finding the optimal
thresholds. The proposed algorithm is more efficient than standard
mechanisms for solving MDPs.