  Performance and reliability of content access in mobile networks is
conditioned by the number and location of content replicas deployed at the
network nodes. Location theory has been the traditional, centralized approach
to study content replication: computing the number and placement of replicas in
a static network can be cast as a facility location problem. The endeavor of
this work is to design a practical solution to the above joint optimization
problem that is suitable for mobile wireless environments. We thus seek a
replication algorithm that is lightweight, distributed, and reactive to network
dynamics. We devise a solution that lets nodes (i) share the burden of storing
and providing content, so as to achieve load balancing, and (ii) autonomously
decide whether to replicate or drop the information, so as to adapt the content
availability to dynamic demands and time-varying network topologies. We
evaluate our mechanism through simulation, by exploring a wide range of
settings, including different node mobility models, content characteristics and
system scales. Furthermore, we compare our mechanism to state-of-the-art
approaches to content delivery in static and mobile networks. Results show that
our mechanism, which uses local measurements only, is: (i) extremely precise in
approximating an optimal solution to content placement and replication; (ii)
robust against network mobility; (iii) flexible in accommodating various
content access patterns. Moreover, our scheme outperforms alternative
approaches to content dissemination both in terms of content access delay and
access congestion.
