Accession Number : ADA304462

Title :   Real-Time Compressed Video Transmission Across the Common Data Link.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Walker, T. O., III

PDF Url : ADA304462

Report Date : JUN 1995

Pagination or Media Count : 116

Abstract : The advances in high speed computer networks and digital communication techniques have enabled the rapid and extensive dissemination of information throughout the modern defense infrastructure. One of the challenges in networking today is real-time dissemination of information. This thesis proposes a solution for a specific aspect of this challenge, namely, the transmission of real-time compressed video data across the Common Data Link (CDL), a high-speed military data link designed to operate in high error environments. Current research is primarily focused on the transmission of real- time data across low-error links. This thesis proposes, simulates, and analyzes a mechanism which guarantees that (1) delay bounds are met for real-time flows despite network overload and (2) a minimum acceptable image quality is maintained despite the presence of highly correlated errors. These highly correlated errors are characteristic of the type of electromagnetic jamming likely to be encountered by the CDL. This mechanism consists of four fundamental requirements: (1) a hierarchical image compression scheme, (2) rate control at the source, (3) bandwidth allocation within all encountered network nodes, and (4) dynamic forward error correction. The proposed solution is modeled in the OPNET simulation environment, and the validity and feasibility of the mechanism are verified. In addition, the simulation is interfaced with a compression/decompression algorithm running in MATLAB to enable the subjective analysis of actual images before and after transmission in various jamming scenarios. The results demonstrate the effectiveness of the proposed solution in meeting delay guarantees and maintaining image quality.

Descriptors :   *DATA TRANSMISSION SYSTEMS, *REAL TIME, *DATA COMPRESSION, *DATA LINKS, *MICROWAVE COMMUNICATIONS, *VIDEO NETWORKS, COMPRESSION, ALGORITHMS, SCENARIOS, SIMULATION, ENVIRONMENTS, HIGH RATE, INFORMATION TRANSFER, COMPUTERS, DYNAMICS, RATES, THESES, NODES, TIME, TRANSMITTANCE, QUALITY, ELECTROMAGNETIC RADIATION, IMAGES, ERRORS, DELAY, JAMMING, FLOW, COMPUTER NETWORKS, BANDWIDTH, HIERARCHIES, DIGITAL COMMUNICATIONS, VIDEO SIGNALS, OVERLOAD, CORRECTIONS, FREQUENCY ALLOCATION.

Subject Categories : Computer Systems
      Radio Communications
      Recording and Playback Devices

Distribution Statement : APPROVED FOR PUBLIC RELEASE