HDHomeRun 4K and PLPs

ATSC 3.0 Forum
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HDHomeRun 4K and PLPs

Post by nickk »

The screenshot below shows a typical multi-PLP ATSC3 physical channel in HDHomeRun Config GUI.

Physical Layer Pipes (PLPs) divide the physical channel up into time slots to support multiple modulation schemes on the same physical channel.

In some cases multiple PLPs on the same physical channel can be tuned using a single tuner, however as per the ATSC3 standard the PLPs that can be concurrently tuned depend on the time interleaving used by the broadcaster. Physical channel 27 in Phoenix for example uses CTI interleaving of two qam256 PLPs which cannot be concurrently tuned using a single tuner.

The HDHomeRun 4K and the HDHomeRun Config GUI will attempt to tune any manual PLP combination requested and will not block invalid combinations. If a combination is invalid the PLPs will fail to lock.

If a program shows no-data or fails to play the channel data may be on a different PLP.

Low level command to request channel 27 with concurrent PLPs 0, 1, 2, and 3:
hdhomerun_config <device id> set /tuner0/channel atsc3:27:0+1+2+3

Low level command to get the PLP info for a tuned channel:
hdhomerun_config <device id> get /tuner0/plpinfo

If no PLP is specified when tuning the HDHomeRun 4K will pick the first PLP.

The HDHomeRun 4K has 4 tuners, of which tuner0 and tuner1 support ATSC3. Be sure to specify tuner0 or tuner1 if manually tuning an ATSC3 channel.
atsc3_hdhomerun_config_gui.png (17.03 KiB) Viewed 6133 times