|Thesis abstract: |
Internet traffic keeps growing at fast pace as a consequence of the steadily increasing number of users and the adoption of new bandwidth-intensive services (such as video services). To reduce network traffic and improve QoS/QoE for end users, caching schemes have been proposed in Content Delivery Networks (CDNs). In the last years, CDN infrastructures have been deployed in backbone/metro wired networks, where a set of CDN servers are distributed to replicate content and facilitate its delivery to end users. Commercial CDNs like Akamai and Limelight have been successfully deployed in the current Internet. Recent reports show that more than one third of Internet traffic was carried by CDNs in 2013, and by 2018 the share of traffic supported by CDNs will grow to 55%.
Moreover, due to the increasing popularity of smart phones and mobile applications, mobile Internet is also expanding rapidly. In particular video mobile traffic is expected to grow dramatically, but the current appeal for higher definition video content is hampered by the current limitation of mobile (both wireless and backhaul) network capacity. Therefore CDNs are expected also to be integral part of next generation mobile 5G networks, whose network elements are being designed to provide the resources upon which CDN can deploy edge delivery functionalities. Also the satellite broadcast/multicast content capabilities are expected to enables to offload a significant part of the traffic by serving the most popular on-demand as well as live content towards the edge nodes of the network.
Moreover, significant energy savings are expected to be enabled leveraging CDN capabilities. The general principle for energy saving in telecom network is to aggregate traffic in order to be able to turn off a maximum number of devices. It has already been shown how the choice of CDN servers impacts the backbone energy consumption, but such analysis in other network domains have not been performed yet.
Hence, CDN is promising paradigm to ensure cost and energy efficient network scalability in the next years. CDN is expected to play a (crucial yet different) role according to the supported content service and the network technology involved and in this thesis we aim at exploring novel strategies for caches deployment and operation in different networking and service domains.