Re: IP over DVB-S2

[Fausto Vieira <fvieira@sunaut.uab.es>]

Due to the different length sizes for the data fields, clearly the first 
objective is:
- Support multiple IP packets in one data field.

A not so obvious one is the support for packet segmentation.
For me, I would be in favour of making this optional. When you have 
large data fields, you loose at maximum 11999 bytes (8*MTU-1 bit).
But of small data fields this is quite important.
Of course, the delay could have important consequences. Imagine the 
scenario where you transmit the first part of the packet in one data 
field. In the next scheduler slot, the user is experiencing bad channel 
conditions and if you transmit in the same data field, the user will 
receive the packet corrupted. This would mean that by system design, the 
segmented packets would need to be outside the mechanism that decides 
the appropriate Coding and modulation rate.

I don't know if I was very clear with this example.



--
Fausto Vieira
Researcher
Dpt. Telecomunicació i d'Enginyeria de Sistemes
ETSE - UNIVERSITAT AUTÒNOMA DE BARCELONA
Campus Universitari, s/n
08193 Bellatera Barcelona SPAIN
Phone :(34) 935813843
Fax   :(34) 935814031