Accessing remote cloud services usually involves high network latencies. To deal with this issue, several models of local cloudlets have been proposed, but most of which are based on powerful desktop machines running continuously and constantly to provide services to nearby users. In this paper, we propose a more ubiquitous solution based on less powerful but considerably more accessible machines, namely mobile smartphones. We envision a network of cloudlets distributed within a geographic area, connected to a root server that keeps track of their online presence and resource availability. Our framework is especially suitable for environments where cloud clients are interested in network and software services, in information and data generated and updated by applications or cached from accesses to remote cloud centers. We use the CloudSim simulator to evaluate the performance of the proposed solution and compare it with a peer solutions found in the literature.

Device-to-device (D2D) offloading has been shown to be a highly effective technique to enhance the performance of wireless networks. Yet, for any two mobile users to share data efficiently and reliably via D2D links, they should be in close proximity for long enough period of time, share similar content interests, and have some level of incentive and trust to cooperate. In this work, we focus on the practical implementation aspects of D2D data sharing taking into account realistic operational conditions. To this end, we design and conduct an experimental study to collect location and neighbor discovery data from 38 mobile users in a university campus over several weeks using our own customized crowdsourcing Android mobile application. The collected data is then processed and utilized to empirically model mobility-related parameters that include contact frequency, contact duration, and intercontact duration. The participating users did also fill a user interest survey in order to correlate mobility and connectivity patterns with content interests and social network relations. The obtained insights are then used to develop a practical implementation framework for designing effective D2D data sharing strategies. To test the proposed ideas under realistic operational constraints, we design and implement a social-aware D2D data sharing Android mobile application and demonstrate its functionality and effectiveness using an example case study scenario.