Collaborative and adaptive mobile device-resident service architectures

Mobile devices, such as smartphones and personal media players, have recently significantly increased in popularity thanks to the rich set of mobile cloud services that they allow users to access. Networked vehicular computing devices are also expected to be commonplace in the near future, as they will enable a wide range of driver assistance services. The ubiquitous penetration of mobile services, however, has been thwarted by their poor user experience; access to mobile cloud services typically occurs over slow and costly long-range cellular communications. This thesis focuses on improving the user experience of mobile services by reducing the need for costly long-range cellular communications. To achieve this, the thesis proposes to host more service functionality on mobile devices themselves. In this way, mobile devices are often able to serve requests either locally or by contacting neighbor devices over short-range communications. Two novel mobile service architectures are proposed for the two different types of mobile services: traditional non-geo-locality services and emerging geo-locality services. A service is termed to have the geo-locality property when its data are both generated (sensed or input) and consumed locally, i.e., within a specific geographic region. In other words, for services that have the geo-locality property, only mobile devices within a specific geographic region R can generate the necessary service data and only devices within the very same region R are interested in consuming it. For non-geo-locality services, the data is generated either by cloud servers or by users regardless of their location. Data generation and/or consumption are also typically a function of the users’ personal interests and not of their geographic location. For traditional non-geo-locality services, this thesis proposes the Pocket Cloudlets architecture. The Pocket Cloudlets architecture is a mobile device-resident caching scheme that serves cloud service requests locally on the device, when possible, significantly reducing the need for slow and costly long-range communications. The Pocket iii Cloudlets architecture leverages both personal user and collaboratively-generated community access patterns to selectively replicate parts of the cloud service locally on the mobile device. Pocket Cloudlets are also adaptively updated by detecting emerging popular service data items and prefetching them on the mobile device. Our analysis shows that the proposed Pocket Cloudlets architecture can effectively augment several traditional cloud services, like mobile web search. PocketSearch, our prototyped mobile search pocket cloudlet, reduces the average service access time by a factor of 2.7× and the required communication bandwidth by 66%. For emerging geo-locality services, the thesis presents the Region-Resident Services (RegReS) middleware. RegReS allows a rich set of emerging geo-locality services to be fully supported on confederations of mobile devices. Mobile devices collaborate to provide a geo-locality service within a specified region and over a specified service lifetime by utilizing only short-range ad-hoc communications. In this way, RegReS completely eliminates the need for long-range cellular communications. Although mobile devices are becoming increasingly powerful, their resources are constrained and should be used judiciously. RegReS enables the efficient provision of geo-locality services by allowing services to specify their target service carrier density. Only as many service carriers as specified are subsequently maintained by RegReS. As opposed to previously proposed static schemes, RegReS employs a fully distributed, collaborative and adaptive estimation scheme to track the existing service carrier density and make decisions about the spawning of new carriers, when necessary. Thanks to collaboration and adaptation, RegReS can maintain the desired density with only 16% mean absolute error across a wide range of configurations. To demonstrate the potential of collaborative mobile device-based computing platforms that are enabled by middleware like RegReS, the thesis presents a rich set of novel services that such platforms can enable. More specifically, the thesis focuses on the type of services that are typically most challenging and resource-intensive