Zac read our recent post about Comcast randomly throwing advertisements in the middle of cartoons and other programming. He let us know that the errant commercials can be explained by science. Broadcasting technology science, that is!

Basically, the cable companies (Time Warner, Comcast, etc.) pay subscription fees to cable networks (CNN, ESPN, etc.). The cable companies pay a lot for the channels, and in return get the right to air their own commercials for a specified time every hour. They then get the revenue from the commercial airings.

The networks send a signal, usually inaudible, that tells the local cable company when to insert the local commercial. It is not time based triggering, it is based on this signal.

If you listened to CNN years ago, you used to be able to hear the audible cue tones (like a touch tone phone) just before the commercial breaks.

It appears that the local company or the network is signaling incorrectly that a local ad can run.

Aha! So our readers who theorized that something might be wrong with the ad-serving software at local Comcast headquarters. This probably also explains why, heading back to “The Daily Show” from commercial break, I sometimes see half a second of the Enzyte commercial that would have aired had my local Time Warner not inserted their own ad instead.

A little bit of research turned up the specifications for some channels’ local avail signaling tones. For example. here are the notes given to cable providers about when they can place ads on CNBC (even during infomercials):

CUE TONES: Tones are generated on a dedicated DTMF port on the rear of the IRD. Please consult the manufacturers documentation for connection information.
PRE-ROLL: 08
3 MINUTES PER HOUR: CNBC Programming
Local Commercial Times : :60 Floating Break Between :03 – :17
:60 Floating Break Between :24 – :34
:60 Floating Break Between :41 – :51

Sponsored Programming:
:28: 30 :90 Hard Break
:58: 30 :90 Hard Break

TONES: 622* (Local avail on)
622# (Local avail off)

PREVIOUSLY: Comcast Won’t Let Me Watch Cartoons!

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