A Two-Level Flow Control Scheme for High Speed Networks

Many new network applications demand interprocess communication (IPC) services with guaranteed bandwidth, delay, and low. Existing transport protocol mechanisms have not been designed with these service objectives. Large bandwidth-delay products of high-speed networks also render the existing flow control mechanism inefficient. This paper presents the design, evaluation, and implementation of a two-level flow control scheme that can support efficient IPC for these applications in high-speed network environments

An Application-Oriented Error Control Scheme for High Speed Networks

Many new network applications demand interprocess communication (IPC) services that are not supported by existing transport protocol mechanisms. Large bandwidth-delay products of high-speed networks also render the existing control mechanisms such as flow and error control less efficient. In particular, new error control schemes that can provide variable degrees of error recovery according to the applications requirements are needed. This paper presents the design, evaluation, and implementation of an application-oriented error control scheme that is aimed at supporting efficient IPC in high-speed networking environments. Our results show that the proposed error control scheme allows effective control of trade-off between the amount of error an application can tolerate and the amount of delay it suffers

An Overview of Segment Streaming for Efficient Pipelined Televisualization

The importance of scientific visualization for both science and engineering endeavors has been well recognized. Televisualization becomes necessary because of the physical distribution of data, computation resources, and users invovled in the visualization process. However, televisualization is not adequately supported by existing communication protocols. We believe that a pielined televisualization model (PTV) is suitable for efficient implementation of most visualization applications. In order to support this model over high speed networks, we are developing a segment streaming interprocess communication (IPC) mechanism within the Axon communication architecture. Important aspects of this development include: the segment streaming paradigm which supports low-overhead communication as well as concurrency between the communication and local computation; a two-level flow control method for distributed pipeline synchronization; and an application-oriented error control method which allows error control to be optimized for different applications. This paper describes a set of ideas that lead to the design of this IPC mechanism

Segment Streaming for Efficient Pipelined Televisualization

The importance of scientific visualization for both science and engineering endeavors has been well recognized. Televisualization becomes necessary because of the physical distribution of data, computation resources, and users involved in the visualization process. However, televisualization poses a number of challenges to the designers of communication protocols. A pipelined televisualization (PTV) model is proposed for efficient implementation of a class of visualization applications. Central to the proposed research is the development of a segment of streaming IPC (interprocess communication) mechanism in support of efficient pipelining across very high speed internetworks. This requires exploration of special issues arising from extending a pipeline across networks with errors and high latency, determination of alternative solutions, and evaluation of such solutions. The novel aspects of the proposed segment streaming mechanism include a two-level flow control method and an intelligent error control mechanism

Axon: Application-Oriented Lightweight Transport Protocol Design

This paper describes the application-oriented lightweight transport protocol for object transfer (ALTP-OT) in the Axon host communication architecture for distributed applications. The Axon Project is investigating an integrated design of host architecture, operating systems, and communication protocols to allow the utilization of the high band-width provided by the next generation of communication networks. ALTP-OT provides the end-to-end transport of segment and message objects for interprocess communication across a very high speed internetwork, supporting demanding applications such as scientific visualization and imaging. ALTP-OT uses rate-based flow control specifically oriented to the transfer of objects directly between application memory spaces. This document is intended to present the design of ALTP-OT, rather than serve as a complete specification and implementation report. It should be treated as a request for comments, and will be periodically updated to reflect comments form the research community and progress on Axon design and prototype implementation. Last revision April 5, 1990

Empirical exploration of air traffic and human dynamics in terminal airspaces

Air traffic is widely known as a complex, task-critical techno-social system, with numerous interactions between airspace, procedures, aircraft and air traffic controllers. In order to develop and deploy high-level operational concepts and automation systems scientifically and effectively, it is essential to conduct an in-depth investigation on the intrinsic traffic-human dynamics and characteristics, which is not widely seen in the literature. To fill this gap, we propose a multi-layer network to model and analyze air traffic systems. A Route-based Airspace Network (RAN) and Flight Trajectory Network (FTN) encapsulate critical physical and operational characteristics; an Integrated Flow-Driven Network (IFDN) and Interrelated Conflict-Communication Network (ICCN) are formulated to represent air traffic flow transmissions and intervention from air traffic controllers, respectively. Furthermore, a set of analytical metrics including network variables, complex network attributes, controllers' cognitive complexity, and chaotic metrics are introduced and applied in a case study of Guangzhou terminal airspace. Empirical results show the existence of fundamental diagram and macroscopic fundamental diagram at the route, sector and terminal levels. Moreover, the dynamics and underlying mechanisms of "ATCOs-flow" interactions are revealed and interpreted by adaptive meta-cognition strategies based on network analysis of the ICCN. Finally, at the system level, chaos is identified in conflict system and human behavioral system when traffic switch to the semi-stable or congested phase. This study offers analytical tools for understanding the complex human-flow interactions at potentially a broad range of air traffic systems, and underpins future developments and automation of intelligent air traffic management systems.Comment: 30 pages, 28 figures, currently under revie

Organization of Communication with the Unmanned Aerial Vehicle in a Combined Data Transmission Network

Communication with UAV (Unmanned Aerial Vehicle) can be organized using terrestrial radio (high efficiency, but limited in terms of service area) and satellite (global coverage area, but large delay in propagation of radio signals) communication networks. Their integration will ensure high efficiency and reliability of information interaction with UAV. The task of dynamic control of information flows to ensure the specified characteristics is relevant. The article analyzes the algorithm for managing information flows when a communication session with UAV is performed through that segment of the network (terrestrial or satellite one), which at the moment will provide the maximum efficiency of information delivery. A mathematical model of information exchange in this integrated communication network as a queuing network with Poisson incoming traffic and exponential distribution of the volume of transmitted information has been developed. Ratios are obtained for calculating the average network delay depending on the ratio between throughputs of satellite and terrestrial segments of integration of the communication network. The proposed model allows selecting the required bandwidth of satellite and terrestrial segments of communication networks, where the specified requirements for the speed of information delivery are provided. The use of dynamic flow control can significantly increase the efficiency of information exchange with UAV