THE KEY TO ROBUST DATA QUALITY ENCAPSULATION: ASYNCHRONOUS DQE FRAMING

Abstract

A data quality encapsulation (DQE) protocol for transporting received telemetry data along with a data quality metric (DQM) is defined in IRIG 106-23 Chapter 2 Appendix 2-G. DQM provides real-time link status and is sufficient for optimal telemetry reception from multiple sources using a downstream best source selector (BSS). Recent testing has revealed that receiver synchronization issues in challenging RF channels can result in DQE framing errors in the output data stream. At best, invalid frames may be ignored or assigned a poor quality. At worst, the DQM value may be misinterpreted as good when the TM data is bad resulting in BSS bit errors. In any case, data correlation/alignment may be undermined. The root cause stems from trying to maintain alignment of the streaming DQM output values with the over-the-air modulation or coding blocks. This paper proposes asynchronous DQE framing relative to the physical layer and presents an analysis of the relative loss in system performance.