More and more large-scale real-time distributed control and data processing systems are deployed to support the nation?s infrastructures and critical services, such as power grid control, transportation monitoring systems, and water processing systems. Due to their large scale deployment, these systems pose very different requirements, compared with traditional real-time systems. They generally require soft (predictable) real-time delivery over multiple domains on dynamic networks. These requirements cannot be met using current overprovision or reservation-based solutions. This project investigates a promising solution to effectively address this issue across multiple domains. The fundamental issues in supporting large-scale predictable real-time delivery on the Internet, by addressing the predictability in the network layer are studies here. In particular, the project explores the ready-available time synchronization technology, such as GPS, CDMA, and IEEE 1588 Precision Time Protocol, to achieve predictable delivery over multiple domains and dynamic paths. Two key mechanisms are developed to estimate the delay from a router to a destination and service a packet based on its upstream earliness and downstream laxness for more efficient resource sharing among partially-overlapping flows. The results from this project will provide a viable practical solution to support large-scale distribution control systems and enable more powerful applications in power control, traffic monitoring, and energy management. The research results will be shared with the broad community via journal and conference publications. A prototype system will be built to illustrate the effectiveness of the proposed system. This project will work with Native Hawaiian Science and Engineering Mentorship Program to broaden the participation of minority students.
Motivations: The main research of this project is to achieve large-scale predictable real-time delivery in a scalable and efficient fashion. Although the Internet has been a great success, it is still unable to support large-scale real-time data communications required by many emerging applications, e.g., the communication networks of Smart Grid need exchange a massive amount of data between smart meters, control centers, and power traders. Currently, they have to depend on private networks with dedicated lines, which are expensive and inefficient. As many such infrastructure networks are connected with the Internet technology, it is urgent and important to find an efficient method to address this issue. This project is addressing the issues in this direction. Approaches and Impact: With broad-available new time synchronization technologies such as GPS and IEEE 1588 Precision Time Protocol, we propose a new method to deliver real-time traffic across large areas in order to address the above issue. Our research shows that, with synchronized time, we can able to achieve predictable performance with hard reservations as in the current solutions. Such a solution is built on two subsystems: a new path-aware delay measurement system on routers and a multi-hop collaborative scheduling scheme at routers. The proposed framework can be easily applied to many emerging large-scale real-time applications, such as Smart Grid. Our research shows that the proposed solution can significantly reduce the cost to build a large-scale real-time communication network and still meet the requirements of various applications. Currently, we are focusing on such applications and developing customized solutions to further improve the performance and reliability of the proposed framework.
