Content replication in mobile wireless networks

The growth of mobile devices and network-based services nowadays has raised a timely
question on how to efficiently distribute the data items to mobile users. Network applications
need data as an input to process and provide information to users. Consequently,
data traffic exerted by mobile devices fetching content is a drainage of mobile operators'
network resources. Similar to the wired Internet, mobile users are now coping with the
congestion at network gateways and due to the unpredictability of human mobility, mobile
service providers cannot sufficiently provision infrastructures for their customers.
Content replication in this context has been proved as a good solution to enhance network
performance and scalability. In this thesis, we tackle the issues of content replication
in heterogeneous mobile networks. Such scheme requires us to solve two basic questions :
where and how many replicas should be placed in the system. We study the solution
through the lenses of facility location theory and design a distributed mechanism that reduces
content access latency and avoids congestion at mobile gateways. Additionally, we
consider the resource constraints of mobile devices and introduce a P2P cache-and-forward
mechanism for load balancing purpose. We evaluate our mechanisms against realistic human
mobility models.
Finally, to address rational users who may behave selfishly in replicating content, we
derive a cost model and study content replication scheme using tools akin to game theory.
We focus on the replication factor under a flash-crowd scenario with different wireless bit
rates. Based on the theoretical findings, our future work is to develop the strategies to be
implemented in a practical network setting.