An emerging paradigm or just another trajectory? Understanding the nature of technological changes using engineering heuristics in the telecommunications switching industry

The theoretical literature on technological changes distinguishes between paradigmatic changes and changes in trajectories. Recently several scholars have performed empirical studies on the way technological trajectories evolve in specific industries, often by predominantly looking at the artifacts. Much less - if any - empirical work has been done on paradigmatic changes, even though these have a much more profound impact on today's industry. It follows from the theory that such studies would need to focus more on the knowledge level than on the artifact level, raising questions on how to operationalize such phenomena. This study aims to fill this gap by applying network-based methodologies to knowledge networks, represented here by patents and patent citations. The rich technological history of telecommunications switches shows how engineers in the post-war period were confronted with huge challenges to meet drastically changing demands. This historical background is a starting point for an in-depth analysis of patents, in search of information about technological direction, technical bottlenecks, and engineering heuristics. We aim to identify when such changes took place over the seven different generations of technological advances this industry has seen. In this way we can easily recognize genuine paradigmatic changes compared to more regular changes in trajectory.technological trajectories; patents; network analysis; telecommunication manufacturing industry

Spacelab system analysis: A study of the Marshall Avionics System Testbed (MAST)

An analysis of the Marshall Avionics Systems Testbed (MAST) communications requirements is presented. The average offered load for typical nodes is estimated. Suitable local area networks are determined

An analysis and Simulation Tool of Real-Time Communications in On-Chip Networks: A Comparative Study

International audienceThis paper presents Real-Time Network-on-chip-based architecture Analysis and Simulation tool (ReTiNAS), with a special focus on real-time communications. It allows fast and precise exploration of real-time design choices onto NoC architectures. ReTiNAS is an event-based simulator written in Python. It implements different real-time communication protocols and tracks the communications within the NoC at cycle level. Its modularity allows activating and deactivating different NoC components and easily extending the implemented protocols for more customized simulations and analysis. Further, we use ReTiNAS to perform a comparative study of analysis and simulation for different communication protocols using a wide set of synthetic experiments

Spacelab system analysis: A study of communications systems for advanced launch systems

An analysis of the required performance of internal avionics data bases for future launch vehicles is presented. Suitable local area networks that can service these requirements are determined

Monthly progress report

This report is the mid-year report intended for the design concepts for the communication network for the Advanced Solid Rocket Motor (ASRM) facility being built at Yellow Creek near Iuka, MS. The overall network is to include heterogeneous computers, to use various protocols, and to have different bandwidths. Performance consideration must be given to the potential network applications in the network environment. The performance evaluation of X window applications was given the major emphasis in this report. A simulation study using Bones will be included later. This mid-year report has three parts: Part 1 is an investigation of X window traffic using TCP/IP over Ethernet networks; part 2 is a survey study of performance concepts of X window applications with Macintosh computers; and the last part is a tutorial on DECnet protocols. The results of this report should be useful in the design and operation of the ASRM communication network

Information Switching Processor (ISP) contention analysis and control

Future satellite communications, as a viable means of communications and an alternative to terrestrial networks, demand flexibility and low end-user cost. On-board switching/processing satellites potentially provide these features, allowing flexible interconnection among multiple spot beams, direct to the user communications services using very small aperture terminals (VSAT's), independent uplink and downlink access/transmission system designs optimized to user's traffic requirements, efficient TDM downlink transmission, and better link performance. A flexible switching system on the satellite in conjunction with low-cost user terminals will likely benefit future satellite network users

Space Shuttle/TDRSS communication and tracking systems analysis

In order to evaluate the technical and operational problem areas and provide a recommendation, the enhancements to the Tracking and Data Delay Satellite System (TDRSS) and Shuttle must be evaluated through simulation and analysis. These enhancement techniques must first be characterized, then modeled mathematically, and finally updated into LinCsim (analytical simulation package). The LinCsim package can then be used as an evaluation tool. Three areas of potential enhancements were identified: shuttle payload accommodations, TDRSS SSA and KSA services, and shuttle tracking system and navigation sensors. Recommendations for each area were discussed

Traffic Management and Congestion Control in the ATM Network Model.

Asynchronous Transfer Mode (ATM) networking technology has been chosen by the International Telegraph and Telephony Consultative Committee (CCITT) for use on future local as well as wide area networks to handle traffic types of a wide range. It is a cell based network architecture that resembles circuit switched networks, providing Quality of Service (QoS) guarantees not normally found on data networks. Although the specifications for the architecture have been continuously evolving, traffic congestion management techniques for ATM networks have not been very well defined yet. This thesis studies the traffic management problem in detail, provides some theoretical understanding and presents a collection of techniques to handle the problem under various operating conditions. A detailed simulation of various ATM traffic types is carried out and the collected data is analyzed to gain an insight into congestion formation patterns. Problems that may arise during migration planning from legacy LANs to ATM technology are also considered. We present an algorithm to identify certain portions of the network that should be upgraded to ATM first. The concept of adaptive burn-in is introduced to help ease the computational costs involved in virtual circuit setup and tear down operations