Co-ordination channels for digital satellite news gathering (DSNG)

Abstract

This paper presents, in Section 1, a new approach to realising co-ordination channels for digital satellite news gathering (DSNG). The key element of the approach to the co-ordination channels is a direct-sequence spread-spectrum processing of the data to be transmitted which allows for the realization of an in-band transmission of the co-ordination channel signals overlaying the DSNG main channel, the part of the system which is responsible for the transmission of the audio/video signal on a point-to-point basis. The system is analysed in theory, simulation, and measurement with respect to system performance and degradation of the DSNG main channel. It shows superior system performance combined with a maximum of operational simplicity while the degradation of the DSNG main channel remains affordably low. Section 2 describes the DVB-DSNG system for co-ordination channels which incorporates many elements of the system presented in the first part but is modified in some details in order to increase system flexibility. One of these details concerns the possibility to perform in-band transmission as well as transmission in the roll-off frequency space of the DSNG main channel. In-band transmission has the advantage of great operational simplicity and is nearly identical to the system presented in Section 1. What characterizes the transmission in the roll-off frequency space is the fact that it is more robust and DSNG main channel degradation is negligible, but this at the price of decreased operational simplicity. Copyright © 2000 John Wiley & Sons, Ltd.