Published: TV Technology Magazine

Issue:  27 July 1998



What is SMPTE 292M?		



By Joe Fedele

			

  The Society of Motion Picture and Television Engineers (SMPTE) currently defines bit-serial 

digital interface specifications for high-definition television systems in the ANSI/SMPTE 292M 

standard. The standard defines a bitstream digital coaxial and fiber-optic interface for HDTV 

component signals operating at data rates of 1.485 Gbps and 1,485/1.001 Gbps.

  The serial data standard is derived from a parallel serial bitstream and specified in a multiplexed 

format that can be used in coaxial or fiber-optic distribution designs. Coax cable interfaces are 

specified with typical losses ranging as high as 20 dB while fiber-optic interfaces are designed for use 

in cable run applications of up to 2 km (1.24 miles).

  The SMPTE 292M standard is similar to the more commonly referenced SMPTE 259M version, 

which covers composite NTSC digital transmissions of 143 Mbps and a component serial digital 

video interface of 270 Mbps and 360 Mbps. 

  SMPTE 259M was last updated in 1993 and also specifies a serial digital interface system for 10-bit 

4:2:2 component and 4 fsc NTSC component video when the signal loss at 70 MHz (4 fsc) or 135 

MHz (4:2:2) due to coaxial cable characteristics does not exceed approximately 30 dB.

  The 292M standard was originally established in 1996 but is now under revision by SMPTE. 



- Joe Fedele