TFP Frame on AbisoverIP or AbisOptimisat

I read a doc (ericsson) talking about Abis optimisation and Abis over IP,
and they talk about TFP frame.
Some one have an idea about a TFP frame
I think that TFP stand for
Traffic forwarding Protocol

refresh about Abis Optimisation:
instead of using (31+1)64kbits TS, on Abis Optimisation, we are using Super Channel (SC)
A SC is a group of at least 8 to 31 TS.
A BTS is able to receive (in Ericsson) 4 SC that are grouped themselves in what we call a SuperChannelGroup SCGR
Traffic and signaling are sent on the SC using a packet protocol.
Using the method of super channel allow to save bandwith
If we use Abis over IP, we still use super channel, but they are talking about TFP-frame and P-GSL frame
The P_GSL frame are the frame that carry I think the GPRS traffic
But what about the TFP frame?