OMVC – ATSC Mobile DTV Receiver Profile Guidelines
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that is stored on the receiver for a period of time and then
transferred via the interactive channel. The transfer of this
information might be coordinated with the delivery of the LTKM.
Broadcasters are expected to require viewers to opt into the
transmission of this data as a condition to access some services.
SFCMM
Scalable Full Channel Mobile Mode is an alternative mode of MDTV
operation that allows higher data rates up to the full channel
capacity for mobile service without assurance of protection for
legacy ATSC services.
See ATSC A/153 Part 9 Scalable Full Channel Mobile Mode.
Short Term Key
Message
Short Term Key Messages (STKM) contain the Service Encryption
Key (SEK) and the Program Encryption Key (PEK). The STKM is
equivalent to an ECM in CAS in a subscription TV system. The
lifetime of the SEK and PEK is very short and must be changed
every few seconds. The STKM is sent via the broadcast channel
and is a small message (100 to 130 bytes). Some broadcasters may
send it in every RS frame to prevent it from increasing channel
change time.
See ATSC A/153 Part 6 Service Protection and ATSC A/154 ATSC
Mobile DTV Recommended Practice.
Trust Authority
The trust authority is an independent agency that administers the
public key infrastructure for the service protection system. The
authority issues unique digital certificates to each MDTV receiver at
the time of manufacturing. In the case of ATSC MDTV, the Open
Mobile Video Coalition has selected Neustar Inc. as the MDTV Trust
Authority. They also will manage the full lifecycle of MDTV trust
relationships from registration to ordering, delivery, authentication,
status checking and revocation.
Unique Device ID
A Device ID is required to uniquely identify the device, which then
becomes an enabler of multiple features such as data collection.
This may be the subjectKeyIdentifier in the x.509 certificate
assigned by the OMVC’s trust authority.
Wake-up Function
There are two types of wake-up functions. The first is based on the
user of the MDTV receiver programming in a specific time to turn on
thus reminding the viewer that a desired program is available. The
programming of this feature might be as simple as clicking on a
specific listing from the program guide.
The second is a function in the ATSC MDTV receiver that will
respond to a specific alerting message and bring the receiver to
operation while it is normally not in use. The function periodically
samples the broadcast transmission looking for the alert code.
