Locus: A Vehicular-based Content Management Network for Location-centric Applications

特定于位置的数据是一类新应用程序的使能组件，这些应用程序可以访问有关特定位置的近实时和最新历史数据，从而驱动诸如车辆路线规划、实时燃油效率和基于位置的数据共享等应用程序。对以位置为中心的应用程序的关注指向在生成数据的地理区域中缓存数据。由于缓存是位置敏感的，而且车辆不断移动，传统的缓存和以内容Web为中心的预取体系结构不适用。此外，现有的集中式方法无法支持这些设备将生成的大量数据。取而代之的是，我们设计了一种分散的数据覆盖层Locus，它本身运行在移动设备之上。为了保持来自该位置附近特定位置的数据，Locus引入了一个新颖的概念，即感知到的数据实际上是由周围地理区域中的节点存储在网络中的，本质上是在网络中提供关于感知数据的本地化存储。通过使用这些位置信息，Locus可以实现更高效的数据存储，并提高数据查找速度。随着越来越多的用户加入网络，Locus的优势将因网络密度的增加而放大，从而随着系统的增长而提高覆盖的性能和价值。通过在车载网络中本地维护内容，Locus降低了对基础设施接入的依赖和成本，使拥有移动数据计划的个人受益，这些计划限制了总下载量或蜂窝数据网络过载的地区。

Location-specific data is the enabling component of a new class of applications that can access near real-time and recent historical data about a specific location, driving applications such as vehicle route planning, real-time fuel efficiency and location-based data sharing. The focus on location-centric applications points towards caching of data in the geographic area where it was generated. Since the cache is location-sensitive and vehicles are constantly on the move, traditional caching and content Web-centric prefetching architectures not apply. Additionally, the large volumes of data these devices will generate cannot be supported by existing centralized approaches. Instead, we have designed Locus, a decentralized data overlay that runs on top of the mobile devices themselves.To keep data from a specific location near that location, Locus introduces the novel concept of "bubbles of knowledge", where the sensed data is actually stored in the network by the nodes in the surrounding geographic area, essentially providing localized memory in the network about the sensed data. By using such location information, Locus can achieve more efficient data storage and improve data look-up rates. As more users join the network, the benefits of Locus will be amplified due to the increasing density of the network, increasing both the performance and value of the overlay as the system grows. By maintaining content locally in the vehicular network, Locus reduces the reliance on and cost of infrastructure access, benefiting individuals with mobile data plans that limit total downloads or regions where the cellular data networks are overloaded.