Different implementation of network level in embedded networking with QoS

Some modern standards in space industry, which are being used in embedded networking designs, provide quality of service features, which are implemented by means of virtual channels. Implementations of virtual channels mechanisms are very different. Each implementation has its latency characteristics for packet flow, hardware cost and performance. These parameters depend on the virtual channels quantity in a port and switch matrix's channels quantity connected to every port (connection point). The connection point quantity can vary from one to a number of virtual channels in port. We consider three structures and implementations of network layer. In the first implementation quantity of connection points is equal to number of virtual channels in a port. In the second - one connection point. The third - one connection point with lower priority data transmission interruption. In this article we compare characteristics of different architecture implementations and structures of port controllers and switch matrix. Also we analyze and simulate proposed mechanism. We present formulas to calculate minimum and maximum data packet transmission latency and compare theoretic and simulation results. Count of virtual channels is 4 for simulation, packet length - 250, 750 bytes. Moreover router's switch matrix hardware cost is evaluated in the article

Space Plug-and-Play Architecture Networking: A Self-Configuring Heterogeneous Network Architecture

The Space Plug-and-Play Architecture (SPA) networking approach outlined in this dissertation is an improvement over the previous approach used by the Satellite Data Model(SDM). The first improvement is the introduction of a SPA network model based on the Open Systems Interconnection (OSI) model. Second, a new addressing and routing scheme is presented, which places the burden of routing on the network infrastructure instead of the network endpoints. These improvements have been implemented in a software infrastructure called the SPA Services Manager (SSM). The SSM was developed under an International Organization for Standardization (ISO) 9001 certified development process, the details of which are presented. A collection of network timing graphs that measure latency and jitter of the SPA network is contained in this dissertation, as well as a runtime memory footprint. The maturity of the development process and these initial performance measurements demonstrate that the SSM is qualified for spaceflight

Communication platform for inter-satellite links in distributed satellite systems

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SpaceWire for adaptive systems

SpaceWire is a network-for connecting instruments and other equipment into the payload data-handling system onboard a spacecraft. It provides high-speed (200 Mbits/s), bi-directional communications over point-to-point links and network capabilities using routing switches. One of the key features of Space Wire is its simplicity resulting in low gate count implementations enabling SpaceWire interfaces to be readily included in FPGAs and ASIC devices. Spacecraft systems have to be able to adapt to failures either autonomously or under control from Earth. Space Wire provides support for implementing. fault tolerant links and networks. This paper introduces Space Wire, considers the need for autonomy and adaptive systems in spacecraft and then explores how SpaceWire can support that autonomy.</p