Decoupling Information and Connectivity via Information-Centric Transport

The power of Information-Centric Networking (ICN) architectures lies in their abstraction for communication --- the request for named data. This abstraction promises that applications can choose to operate only in the information plane, agnostic to the mechanisms implemented in the connectivity plane. However, despite this powerful promise, the information and connectivity planes are presently coupled in today\u27s incarnations of leading ICNs by a core architectural component, the forwarding strategy. Presently, this component is not sustainable: it implements both the information and connectivity mechanisms without specifying who should choose a forwarding strategy --- an application developer or the network operator. In practice, application developers can specify a strategy only if they understand connectivity details, while network operators can assign strategies only if they understand application expectations. In this paper, we define the role of forwarding strategies, and we introduce Information-Centric Transport (ICT) as an abstraction for cleanly decoupling the information plane from the connectivity plane. We discuss how ICTs allow applications to operate in the information plane, concerned only with namespaces and trust identities, leaving network node operators free to deploy whatever strategy mechanisms make sense for the connectivity that they manage. To illustrate the ICT concept, we demonstrate ICT-Sync and ICT-Notify. We show how these ICTs 1) enable applications to operate regardless of connectivity details, 2) are designed to satisfy a predefined set of application requirements and are free from application-specifics, and 3) can be deployed by network operators where needed, without requiring any change to the application logic

One-stop stroke management platform reduces workflow times in patients receiving mechanical thrombectomy

Background and purposeClinical outcome in patients who received thrombectomy treatment is time-dependent. The purpose of this study was to evaluate the efficacy of the one-stop stroke management (OSSM) platform in reducing in-hospital workflow times in patients receiving thrombectomy compared with the traditional model.MethodsThe data of patients who received thrombectomy treatment through the OSSM platform and traditional protocol transshipment pathway were retrospectively analyzed and compared. The treatment-related time interval and the clinical outcome of the two groups were also assessed and compared. The primary efficacy endpoint was the time from door to groin puncture (DPT).ResultsThere were 196 patients in the OSSM group and 210 patients in the control group, in which they were treated by the traditional approach. The mean DPT was significantly shorter in the OSSM group than in the control group (76 vs. 122 min; P < 0.001). The percentages of good clinical outcomes at the 90-day time point of the two groups were comparable (P = 0.110). A total of 121 patients in the OSSM group and 124 patients in the control group arrived at the hospital within 360 min from symptom onset. The mean DPT and time from symptom onset to recanalization (ORT) were significantly shorter in the OSSM group than in the control group. Finally, a higher rate of good functional outcomes was achieved in the OSSM group than in the control group (53.71 vs. 40.32%; P = 0.036).ConclusionCompared to the traditional transfer model, the OSSM transfer model significantly reduced the in-hospital delay in patients with acute stroke receiving thrombectomy treatment. This novel model significantly improved the clinical outcomes of patients presenting within the first 6 h after symptom onset

Support Mobile and Distributed Applications with Named Data Networking

The Internet is becoming increasingly mobile. As the the price of smartphones, tablets, and other portable devices becoming more and more affordable, the mobile access to the Internet is becoming the norm.Meanwhile, the current Internet architecture is increasingly challenged by emerging communication patterns. While IP was designed to solve the problem of carrying a point-to-point conversation between two entities, in today's dominant applications, such as video streaming, file sharing, and social networking, users are more interested in obtaining desired content rather than talking to a specific node.Such trends can be expected to continue in the near future and call for a reexamination of the current Internet architecture.Named Data Networking (NDN) is a proposed future Internet architecture that uses data names instead of host addresses for data delivery. The new architecture incorporates principles that have made the IP protocol suite widely adopted and globally scaled (e.g., the hourglass design and end-to-end principle), but changes the fundamental layer of the architecture to one better suited to modern networks and emerging communication patterns.In this dissertation, we study how to support mobile and distributed applications through Named Data Networking. Specifically, we focus on addressing two complementary questions: one is how to provide flexible, secure, and yet simple mobility support that serves the applications' need in the mobile environment, and the other is to how to design distributed applications that can fully exploit the benefits brought by NDN's architectural shift.The first question is motivated by the fact that mobility support in the current Internet still struggles to satisfy the applications' need even though mobility has become a fundamental characteristic of today's Internet. We address this question by providing a new perspective on mobility support in NDN that addresses the weakness in the existing IP mobility solutions as well as utilizes the lessons learned in IP mobility research. By aligning the mobility support with the data-centric nature of the applications, the name-based data retrieval in NDN design, and the broadcast nature of the wireless media, not only does the new approach address the concerns in today's IP mobility solutions, but it also integrates mobility support using the same approach to cover all types of networks in the mobile environment, including ad hoc and delay-tolerant networks.The second problem is motivated by the observation that distributed applications, such as group text messaging, file sharing, multimedia conferencing, and joint editing, have penetrated into our daily lives and drastically changed the communication patterns, calling for a new Internet architecture and new application design patterns that are freed from the constraints imposed by IP's point-to-point communication model. In this work, we take an application-driven approach to explore the new design patterns that can fully exploit the new opportunities brought by NDN. We propose ChronoSync, an efficient and completely distributed dataset state synchronization protocol to simplify the designs of distributed applications. ChronoSync leverages the flexible naming in NDN to simplify the task of maintaining up-to-date knowledge of a dataset, and exchanges the knowledge among all parties in a compact crypto digest form. Differences in dataset usually can be inferred by comparing the digests, and can be efficiently propagated to all parties using NDN's built-in data multicast capability. We also propose a completely distributed and data-centric security design to achieve the goals of providing data provenance and access control to distribute applications in the absence of a central controller. We validate the proposed new design patterns by developing a distributed file sharing application, ChronoShare, that is based on ChronoSync protocol and secured in a data-centric way. Together with the new mobility support approach, our work represents a step towards a new direction of providing useful building blocks in supporting mobile and distributed applications

Let's ChronoSync: Decentralized dataset state synchronization in Named Data Networking

Abstract—In supporting many distributed applications, such as group text messaging, file sharing, and joint editing, a basic requirement is the efficient and robust synchronization of knowledge about the dataset such as text messages, changes to the shared folder, or document edits. We propose Chrono-Sync protocol, which exploits the features of the Named Data Networking architecture to efficiently synchronize the state of a dataset among a distributed group of users. Using appropriate naming rules, ChronoSync summarizes the state of a dataset in a condensed cryptographic digest form and exchange it among the distributed parties. Differences of the dataset can be inferred from the digests and disseminated efficiently to all parties. With the complete and up-to-date knowledge of the dataset changes, applications can decide whether or when to fetch which pieces of the data. We implemented ChronoSync as a C++ library and developed two distributed application prototypes based on it. We show through simulations that ChronoSync is effective and efficient in synchronization dataset state, and is robust against packet losses and network partitions. I

Support Mobility in the Global Internet

Today’s technology trend indicates that billions of handheld gadgets as well as other types of mobile devices will be coming online in the next few years. While the existing Internet mobility standards, namely Mobile IP, is waiting for a wide adoption, cellphone networks are providing the ubiquitous mobility services on a global scale as of today. They have also promoted IP core network architecture and adopted Proxy Mobile IPv6, an extension to Mobile IP, for their mobility service. There is an open question regarding whether the Internet would, or would not, require significant architectural changes to provide universal mobility support at a scale that is likely to go far beyond the scale and scope of today’s cellular telephone services. In this paper, we examine the fundamental differences between the mobility service models provided by Internet and cellphone systems. We argue that decoupling network access control from mobility support can provide an architecturally promising direction for scalable and decentralized mobile communications, and that designing mobility support outside the global routing system can offer an overall best tradeoff as measured by flexibility, manageability, and scalability of the resulting systems. 1

A method for de-embedding s-parameter with high-frequency

During the measurement of s-parameters, using the de-embedding method to remove the influence of fixture is important. The proposed method decomposes the s-parameter of fixture by time domains. Then the ABCD matric is used to remove the decomposed fixture and get the s-parameter of device under test. By designing printed circuit board to do some experiments, and compare the proposed method with the other two traditional methods, AFR and Delta L. The results prove that this method is valid and accurate under high-frequency signal. Due to the facture that the algorithm decomposes first and then de-embeds, it can be applied to the situation that the left and right fixture are different