Appendix R. Carrier Id (Dvb-Cid Metacarrier; Overview; About Metacarrier - Comtech EF Data CDM-570A Installation And Operation Manual

R.1

Overview

CDM-570A/570AL Satellite Modems incorporate a patent-pending carrier identification (CID)
technique that uses MetaCarrier® spread spectrum technology to embed a unique carrier
identification sequence for the transmitted carrier.
The CDM-570A/570AL with MetaCarrier® is used in tandem with the Comtech EF Data
MCDD-100 MetaCarrier® Detection Device to provide a complete MetaCarrier embedding and
decoding solution.
Since the initial release of this technology in the CDM-570A/570AL, the European
Telecommunications Standards Institute (ETSI) has adopted a modified version of Comtech's
original scheme, which is defined in ETSI TS 103 129 – Digital Video Broadcasting (DVB)
Framing Structure, Channel Coding and Modulation of a Carrier Identification System
(DVB-CID) for Satellite Transmission. CDM-570A/570ALs running Firmware Version 1.5.2 or
later fully comply with this new ETSI specification.
R.2

About MetaCarrier

The DVB-CID (MetaCarrier) concept employs a low-speed data sequence containing identifying
information about a host carrier that is spread using Direct Sequence Spread Spectrum (DSSS),
and then combined, at a low power level, directly underneath that host carrier. The composite
signal therefore carries its own embedded identification. The power level and bandwidth of the
MetaCarrier is sufficiently low that it is completely hidden below the host carrier, and has minimal
effect on system Eb/No (approximately 0.1 dB).
DVB-CID operates independent of the modulation and Forward Error Correction (FEC) rate of the
host carrier. In configurations where the carrier is encrypted or uses cryptographic technologies,
the information carried in the DVB-CID is not affected.
Traditionally, the method for identifying an interfering carrier involves using a geo-location system
that, in turn, uses the phase offset from an adjacent satellite to triangulate the approximate
location on the surface of the earth where the interference is being generated. While such "tried-
and-true" geo-locating methods have proven beneficial to satellite operators and service
providers, they are nevertheless imprecise. For example, to find the exact location of the
transmission source in a densely populated area, you must dispatch a helicopter equipped with a
feed horn and spectrum analyzer; the time and cost associated with such methods are significant.
Carrier ID (DVB-CID MetaCarrier)
CDM-570A/570AL Satellite Modem with Optional Packet Processor
Appendix R. CARRIER ID
(DVB-CID M
ETA
R–1
Revision 5
C
ARRIER
MN-CDM570A
®
)