Communication and Interaction Platform

在CCC的第一阶段，我们在这个项目中的主要贡献有两个：第一，我们构建了一个基于流控制传输协议(SCTP)的通用网络平台。该平台提供多种配置，包括使用多条链路进行故障转移或并发多路径传输(CMT)。对于CMT，我们执行了定性评估，并将辅之以定量分析，特别是针对移动场景。完成后，移动性能最好的CMT将在第一阶段结束时实施。第二，我们与CCC中的其他子项目合作：我们为所有考虑的非功能观点所需的属性制定了全面的规范，并定义了合同谈判过程以及与多变更控制层(McCL)相关的体系结构含义。在第二阶段，CCC针对开放的分布式设置与使用开放网络进行通信的协作系统进行通信。尤其是为实现共同目标而分布式操作的安全关键组件(例如，在McCL中)将对它们的通信提出更严格的要求，例如延迟或冗余。我们将增强我们的平台，以支持此类分布式协议及其需求。用例将是子项目用来实现拜占庭容错(BFT)的协议协议，以及子项目用来实现分布式多变化控制器(MCC)的组件。此外，我们还将提供动态组管理来支持系统组的发现和维护。此外，我们将通过使用(1)关于网络链路的密集、多层上下文信息和(2)通信合同来提高平台的可靠性。对于(1)，我们将连接图的概念应用于CCC系统的所有可用网络链路。通过从地理上收集它们的特征，在给定系统轨迹的情况下，即将到来的通信属性应该是可预测的。收集到的信息也将被提供给应用子项目，例如，有助于自我表达车辆的能力。我们将实施高级策略来优化网络链路的使用，以实现不同的、可能是正交的目标，如成本(能源、金钱)或可靠性和冗余性。对于(2)，我们将扩展第一阶段合同的工作，这些合同相对静态地将合同应用于高度动态的网络域，方法是将组件的多级通信合同与将提供理论方法的子项目结合使用。最后，我们将与使用另一个子项目的域的子项目一起建立两个评估设施：(1)由车载节点组成的小型硬件试验台，用于实际部署。(2)一个著名的车辆模拟框架，用于评估大规模部署。

In phase 1 of CCC, our main contributions in this project have been twofold: First, we built a generic networking platform based on the Stream Control Transmission Protocol (SCTP). The platform provides a wide range of configurations including usage of multiple links for failover or Concurrent Multipath Transfer (CMT). For CMT, we performed a qualitative evaluation that will be complemented by a quantitative analysis especially for mobile scenarios. After completion, CMT with the best mobile performance will be implemented at the end of phase 1.Secondly, we collaborated with further subprojects on contracts in CCC: We developed a comprehensive specification of attributes needed by all considered non-functional viewpoints, and defined the contract negotiation process as well as the architecture implications regarding the Multi-Change Control Layer (MCCL).In phase 2, CCC targets open distributed settings with cooperating systems that communicate using open networks. Especially safety-critical components (e. g. in the MCCL) operating distributedly to achieve common goals will demand tighter requirements for their communication, e. g. for delays or redundancy. We will enhance our platform to support such distributed protocols and their needs. Use cases will be the agreement protocols used by a subproject to achieve Byzantine Fault Tolerance (BFT) and components of distributed Multi-Change Controllers (MCCs) by a subproject. Additionally, a dynamic group management will be provided to support discovery and maintenance of groups of systems.Further, we will focus on increasing the reliability of our platform by employing (1) dense, multi-layered context information regarding network links and (2) contracts for communication.For (1), we will apply the connectivity map concept to all available network links of CCC systems. By geographically collecting their characteristics, upcoming communication properties given the trajectory of a system should be predictable. The gathered information will also be provided to the application subprojects, e. g. contributing to the self-representation of the abilities of vehicles. We will implement advanced strategies to optimize the usage of network links towards different, possibly orthogonal objectives such as costs (energy, monetary) or reliability and redundancy in collaboration with a subproject.For (2), we will extend the work on phase 1 contracts which are relatively static towards applying contracts to the highly dynamic network domain by using multi-level communication contracts for components jointly with a subproject which will provide the theoretical methods.Finally, we will setup two evaluation facilities jointly with a subproject using the domain of an other subproject: (1) A small-scale hardware testbed comprised of vehicular nodes for real-world deployments. (2) A renowned vehicular simulation framework for the evaluation of large scale deployments.