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Other • 2-D meshes are one of the easiest topologies to visualize – nodes are connected in a “grid” fashion (see Figure). The simple layout also allows many problems to map easily to the structure of this network. 2-D Mesh and 2-D Toroid 2-D meshes have unequal node degree. The node degree...
3 D Meshes and 3 D Toroids
Other • 3-D meshes and 3-D toroids are similar to 2-D meshes and toroids, except the 3-D mesh/toroid is expanded along the Z-axis to provide another dimensional layer of nodes. In the case of the 3-D toroid, the topmost nodes (along the new Z-axis) are connected to the bottommost nodes (see Figure)....
Acronyms
Other • Acronym Definition A/D Analog-to-Digital (as in A/D converter) ACK Acknowledge ADC Analog-to-Digital Converter API Application Program Interface APID Application Identifier APP Application CCC Cube-Connected Cycles CCITT From French: Comité Consultatif International Téléphonique et Télégraphique International Telegraph and Telephone Consultative Committee CC-NUMA Cache Coherent-Non-Uniform Memory Access CCSDS Consultative Committee for Space...
Advantages of JAS
Other • A modern node-based architecture with reconfigurable node electronics and serial data links between nodes provides the core structure and flexibility needed to enable most of the design strategies. It offers a powerful, yet efficient, modular solution that can be scaled and configured to support payloads of virtually any size and...
Characteristics
Other • The table below describes the characteristics of JAS. Characteristic Definition Modularity Modular, scalable design capable of accommodating a wide range of applications, complexities and performance needs Configurable Topology Flexible, node-based, topologically configurable architecture that can be easily sized, configured and optimized to meet connectivity and robustness needs of a broad...
Coincidence Distribution
Other • The figure below illustrates how the JAS supports intra-payload coincidence and triggering. There are two options: Serial Packets JAS nodes can transmit packetized signals via the communications architecture if latency requirements are not too stringent. Discrete Signals Discrete coincidence and trigger signals can be added to any node through the...
Command and Host Processor Profile
Other • The Command and Host Processor (CH) profile defines a microprocessor-based solution suitable to construct nodes for mission data processing, spacecraft interfaces, and other applications requiring software execution on microprocessor platforms. Nodes based on the CH profile work alongside other nodes within the JAS architecture. The SMAC Profile and the Communication...
Communications Profile
Other • The Communications Profile defines standard interfaces for facilitating communication between nodes within a JAS system. The Communications Profile focuses primarily on communication between payload applications. It leverages industry standards to support network-based communication using serial interfaces. Adherence to the Communications Profile and Communications Specification is the minimum required for a...
Complete and Incomplete Hypercubes
Other • An overall good performer, hypercubes are very reliable and offer good performance. Complete hypercubes have fixed size of 2^d (i.e., 4, 8, 16, 32, 64, etc, nodes) but an extension to this structure (incomplete hypercubes) allows for arbitrary size. Hypercubes are constructed by beginning with two interconnected nodes (a 1-D...
Cube Connected Cycles
Other • Cube-connected cycles (CCC) are structures based on hypercubes (see Figure). Given a hypercube of dimension d, each hypercube node is replaced with a ring of size d. This causes the node degree of all nodes to be fixed at 3 regardless of network size! This structure excels when the port...
Entangled Networks
Other • Entangled networks are a class of networks that attempt to maximize the algebraic connectivity of the topology. These networks can be constructed with explicit complex mathematical methods or approximated by a repetitive random optimization algorithm (which is the method chosen for this analysis) (see Figure). Sample Entangled Networks The repetitive...
Expansion Profile
Other • The Expansion Profile describes a board that provides new capabilities and/or additional resources that would otherwise not be available in standard node instantiations. These modules are not intended to operate standalone and will usually not have individual processing capabilities. Rather, these boards will be populated with components that allow for...
Fully Connected
Other • Fully connected networks are constructed by wiring every node to every other node present in the network (see Figure). For obvious reasons, these networks are the ideal topology when considering overall speed, diameter, routing complexities, reliability, and ease of construction. However, they require a massive number of links; hence, cost...
Generalized Star
Other • The generalized star topology is a topology that attempts to wire the network together in such a way that each node is the center of a small star (see Figure). Given a dimension d, these networks will have d! nodes and each node will have a fixed degree of d-1....
Glossary
Other • Term Definition Adaptability A system design property that refers to an architecture’s ability to be easily changed or adjusted to accommodate different system needs. Address Translation allows addresses to be translated from abstract to physical Atomic An operation during which a processor can simultaneously read a location and write it...
Hybrid Fat Trees
Other • A hybrid fat-tree is an extension to the fat-tree topology. Hybrid fat-trees perform well when minimizing average path length and network diameter. One advantage to this design is typically about half of the nodes in this design will have a fixed degree of 2. However, other nodes have large degree,...
JAS Essential Elements
Other • The following essential elements are the minimum required to develop a JAS-compliant system. Communication Interface (physical, preferably serial) Protocols to communicate over the physical interface Network-connected nodes that implement the communication interface and protocols Network routing and addressing scheme(s) All of these items are tailorable based on recommendations in the...
JAS Profile Introductions
Other • The JAS architecture defines a small number of Profiles that form the basis for building the components required for a sensor interface and data processing electronics system. A node inherits the attributes of one or more Profiles. A Profile describes the purpose of that node within the Architecture and defines...
JAS Rationale and Motivation
Other • JAS is a versatile, scalable, tailorable, SWAP-efficient, node-based concept for implementing embedded systems. Such systems include sensor suites, host platform interfaces, signal and data processors, data buffering and storage, command and data handling, and other supporting hardware and software. JAS Origin Sandia National Laboratories, Los Alamos National Laboratories, and others...
JAS Toolbox Introduction
Other • The JAS standard is captured in the JAS Toolbox, and presented using a web-based content management system known as the Interactive Standards Publication Tool (ISPT). In addition to the JAS standard, the JAS Toolbox includes a set of Systems Engineering (SE) Tools, which provide system examples and modeling capabilities. The...
JAS versus PROPIN Trade Study
Other • Feature Comparison JAS has a number of positive impacts on budget, schedule, and performance. Below is a table that illustrates these advantages when comparing a JAS-based system to a PROPIN approach. Advantage Benefit Budget Schedule Performance Scalable processing systems Ability to add/remove as many nodes as are needed to support...
Joint Architecture Standard Overview
Other • The purpose of JAS is to realize a reusable set of common hardware and software module designs that can be easily scaled, configured, adapted, interconnected and integrated with industry standards and internally supported intellectual property (IP) to provide the functionality needed to support any payload sensor suite. JAS also provides...
Network Topologies
Other • The selection of network topology is a critical component when developing multi-node or multi-point system architectures. A good choice of topology will require less power, have less complexity, higher reliability, and will orchestrate network traffic smoothly and quickly between nodes. Conversely, a poor choice of topology will introduce complex and...
Power Supply Profile
Other • The PS profile defines a high-performance power solution, suitable for powering JAS nodes. The PS profile works alongside other nodes within the JAS architecture. The SMAC and Communications profile implement connectivity and data transfer from PS nodes to other nodes in the system. Power Supply Node The figure below illustrates...
Reconfigurable Processing Profile
Other • The Reconfigurable Processing (RP) profile defines a high-performance processing solution suitable for constructing nodes for mission data processing, sensor interfaces, and other applications requiring high-bandwidth processing and communications. Nodes based on the RP profile work alongside other nodes within the JAS architecture. The SMAC Profile and the Communication Profile implement...
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