SMPTE 259M

"SMPTE 259M" is a standard published by SMPTE which "... describes a 10-bit serial digital interface operating at 143/270/360 Mb/s." The goal of "SMPTE 259M" is to define a Serial Digital Interface (based on a coax cable) this interface is usually called SDI or SD-SDI.
See more at Wikipedia.org...