Offloading Content with Self-organizing Mobile Fogs
29th International Teletraffic Congress (ITC 29), Genoa, Italy, (2017)Abstract
Mobile users in an urban environment access content on the internet from different locations. It is challenging for the current service providers to cope with the increasing demand from large number of collocated mobile users. In-network caching feature to offload content at nodes close to users alleviate the issue, though efficient cache management is required to find who should cache what, when and where in an urban environment, given nodes limited computing, communication and caching resources. To address this, we first define a novel relation between content popularity and availability in the network and investigate a node's eligibility to cache content based on its urban reachability. We then allow nodes to self-organize into mobile fogs to increase the distributed cache with the goal to maximize content availability in a cost-effective manner. However, to cater rational nodes, we propose a coalition game for the nodes to offer a maximum ``virtual cacheassuming a monetary reward is paid to them by the service/content provider. Nodes are allowed to merge into different spatio-temporal coalitions in order to increase the distributed cache size at the network edge. Results obtained through simulations using realistic urban mobility trace validate the performance of our caching system showing a ratio of 60-85% of cache hits compared to the 30-40% obtained by the existing schemes and 10% in case of no coalition.
