==== Software Download Trigger Table (SDTT)

Defined by ARIB in <<ARIB-B21>>.

[source,xml]
----
<SDTT version="uint5, default=0"
      current="bool, default=true"
      table_id_ext="uint16, required"
      transport_stream_id="uint16, required"
      original_network_id="uint16, required"
      service_id="uint16, required">

  <!-- One per download content -->
  <content
      group="uint4, required"
      target_version="uint12, required"
      new_version="uint12, required"
      download_level="uint2, required"
      version_indicator="uint2, required"
      schedule_timeshift_information="uint4, required">

    <!-- One per schedule period -->
    <schedule
        start_time="YYYY-MM-DD hh:mm:ss, required"
        duration="hh:mm:ss, required"/>

    <DESCRIPTOR_LIST>

  </content>

</SDTT>
----
