July 25, 2012

See also: Ad Serving, Redirect

CIMM DEFINITION: The lag time that occurs in the physical distribution plant and some STBs when the box changes channels or uploads so that tuning event timing relative to the same content can occur in one home at a slightly different time than in another home. Can be as much as several seconds.

2: According to TIVO there are several types of Latency: 1. signal distribution Latency where there is a lag in transmission of the signal to the box, 2. channel change Latency which is the time between channel changes and 3. remote Latency when the remote is pressed and the action is logged. Stress loads on the Set-Top Box may impact length of Latency and logging. (Source: TIVO)

3: The amount of time it takes for content to appear on the TV screen once distributed by the Set-Top Box. The lag time that occurs in some boxes when the box changes channels or uploads, or clock slippage. Can be as much as several seconds. (Source: Nielsen)

4: The time it takes for a data packet to move across a network connection. (Source: IAB)

5: The visible delay between request and display of content and ad. (Source: IAB(

NOTE – How is this viewing ascribed, if at all? The standard here appears to be at 5 seconds but this could vary based on the operator and their platforms.

NOTE – Lag time as the box changes channels or uploads. From Weisler Mediapost article there is a comment from John Grono, GAP Research, Sydney Australia)

I would also like to caution analysis of data at the second-by-second level. There is considerable ‘drift’ in STB clocks, and of more importance there are Latency delays in broadcasts across platforms. Here in Australia on fiber-optic cable that Latency is around 8 seconds (the mode). Eight seconds out in a 15-second ad is an eternity! I would recommend some sort of content matching rather than time-based matching if this is an ongoing objective.”

NOTE – Channel change Latency can be affected by the Set-Top Box type, the middleware and resident application running on the Set-Top Box, the encoding of the channel being tuned to (e.g., HD, standard definition digital, analog, encrypted, non-encrypted), and the connection between Set-Top Box and TV (e.g., HDMI, RF, S-Video). Thus, Set-Top Box timing synchronization and editing rules for channel change gaps must be applied for each Set-Top Box individually.

NOTE – Second-by-second measurement is possible if the collection engine on the STB performs time synchronization and measures and collects Latency-related STB timing data, and collection servers apply appropriate editing rules. All times are then synchronized to the content times as they appear in the As Run Logs, regardless of the various distribution and STB latencies. (Source: FourthWall Media)

NOTE – Latency sometimes leads to the user leaving the site prior to the opportunity to see. In streaming media, latency can create stream degradation if it causes the packets, which must be received and played in order, to arrive out of order. (Source: IAB)