Adaptation field use in ULE / MPG2-TS specification

[Tor Brekke <tor.brekke@nbs.nera.no>]

Hello, 

I am jumping into this discussion at
a fairly late stage. Having just read the ULE draft I have to make a comment
about the use of the adaptation field though. In the draft it says that
"TS Packets from a ULE Encapsulator MUST be sent with an AFC value
of '01'", i.e. without adaptation field. Now the adaptation field
contains a private field which according to the MPG2-TS specification (ISO/IEC
13818-1) can be used to transmit system dependent data.  
Now to the question: Why is this limitation
imposed on ULE?  

I have two main reasons to ask this.

1) Firstly there is ongoing work to
use the private adaptation field for network internal signalling in the
DVB-RCS standard. This means that ULE will not work over DVB-RCS systems
employing the adaptation field signalling. 
2) As far as I have been able to determine
all other encapsulation forms over MPG2-TS are transparent to the adaptation
field, i.e. the adaptation field and payload are handled independently
(even though there may be an implicit connection between them). It seems
strange to break this logicinf the MPG2- TS mechanism for a new encapsulation
type. 

Best Regards
Tor Brekke
Nera Broadband Satellite AS.