NeTS: Medium: Mobile Computing over Intermittently Connected Networks

越来越多的人依赖移动设备来提供许多服务，这些服务超越了简单的连接，需要更复杂的处理。这样的应用程序已经成为日常生活中不可或缺的一部分。这要归功于两个趋势。首先，真正便携的移动设备，如智能手机和平板电脑，是功能越来越强的设备，具有处理和存储能力，每一代都有显著的进步。第二个趋势是移动设备的改进的连接选项的可用性，这些移动设备通过利用远程处理和存储使应用程序能够超越单个设备的能力。如今广泛使用的实现这种远程处理的主要方法是利用标准云计算资源将某些移动应用程序中可能需要的重担卸载到专门指定的服务器或服务器集群。另一种用于移动应用程序的远程处理的技术提出了使用Cloudlet，其使用虚拟机技术在附近的计算资源上实时提供实例化的软件。这项先前的工作假定基于基础设施的计算资源的可用性，并且在计算任务的持续时间内还需要良好的、持续的到此类资源的连接。这使得处理移动设备的间歇性连接这一重要而具有挑战性的问题没有得到解决。这项工作将推广远程移动计算范例，使其能够在存在间歇连接的情况下运行。这进而提供了利用更多计算资源的重要能力，包括由断断续续连接的Cloudlet提供的资源，甚至其他移动设备上可用的资源。我们的工作可以被视为实现了网络寻觅的真正一般愿景，即通过利用附近的计算资源，设想移动应用程序“生活在陆地上”。研究工作将由一个跨学科团队进行，其中包括具有移动无线网络、移动环境中的程序划分和执行以及构建涉及分析和解释丰富多媒体数据的应用程序的专业知识的研究人员。这项工作将包括：1)为具有不同远程计算资源可用性和各种间歇连接特征的多种场景开发远程执行框架，2)为间歇连接环境量身定做应用程序分析和分区，3)试验顺序的和令人尴尬的并行应用程序，以及4)通过概念验证原型和广泛的仿真进行评估。在这样做的过程中，我们借鉴并推动了程序分析、间歇性连接环境中的网络和移动多媒体应用方面的最新进展。在这项研究中开发的统一框架具有概念和实用价值；它为移动应用程序可以利用并动态适应任何可用资源的未来奠定了基础。浏览器影响：工作是多学科的，参与该项目的学生将面临计算机科学学科交叉的问题，如网络、编程语言和分布式处理。我们的研究还将支持在网络边缘运行且没有固定基础设施的应用程序，从而使公民能够在他们所在的地方获得有限的外部依赖。

Mobile devices are increasingly being relied on for a number of services that go beyond simple connectivity and require more complex processing. Such applications have become an indispensable part of everyday life. This has been made possible by two trends. First, truly portable mobile devices, such as smartphones and tablets, are increasingly capable devices with processing and storage capabilities that make significant step improvements with every generation. A second trend is the availability of improved connectivity options for mobile devices which have enabled applications that transcend an individual device's capabilities by making use of remote processing and storage.The primary approach in wide-use today to enable such remote processing makes use of standard cloud computing resources to off-load the 'heavy lifting' that may be required in some mobile applications to specially designated servers or server clusters. Another technique for remote processing of mobile applications proposes the use of cloudlets which provide software instantiated in real-time on nearby computing resources using virtual machine technology. This previous work assumes the availability of infrastructure-based compute resources and additionally requires good, constant connectivity to such resources for the duration of a computational task. This leaves the important and challenging question of handling intermittent connectivity of mobile devices unaddressed. This work will generalize the remote mobile computing paradigm to enable its operation in the presence of intermittent connectivity. This, in turn, provides the important ability to leverage more compute resources including those provided by intermittently-connected cloudlets and even those available in other mobile devices. Our work can be viewed as enabling a truly general vision of cyber foraging which envisions mobile applications 'living off the land' by exploiting nearby computational resources.The research work will be conducted by an interdisciplinary team which includes researchers with expertise in mobile wireless networks, in program partitioning and execution in mobile environments, and in building applications that involve analysis and interpretation of rich multimedia data. The work will include efforts in 1) development of a remote execution framework for a number of scenarios with varying availability of remote compute resources and a diversity of intermittent connectivity features, 2) development of application profiling and partitioning tailored to intermittently-connected environments, 3) experimentation with sequential and embarrassingly parallel applications, and 4) evaluation through proof-of-concept prototypes as well as extensive emulation.Intellectual Merit: This work generalizes the mobile computing paradigm to include full consideration of the increased computational power of mobile devices together with their inherent intermittent connectivity. In doing so, we draw upon and push forward recent advances in program analysis, networking in intermittently connected environments, and mobile multimedia applications. The unified framework developed within this research has conceptual and pragmatic value; it sets the stage for a future in which mobile applications can leverage and dynamically adapt to any and all available resources.Broader Impacts: The work is multi-disciplinary, and the students working on the project will be exposed to problems that lie in the intersection of computer science disciplines such as networking, programming languages, and distributed processing. Our research will also enable applications that run at the edge of the network and without fixed infrastructure, thus empowering citizens where they are, with limited external dependencies.