FACH capacity increase

[mirc84]

Hello,

I have read this thread and it's interesting.
http://www.finetopix.com/showthread....highlight=fach

I would like to know if there is a possibility to increase the FACH channel rate. I understand that the theoretical max capacity of FACH channel is 32kbps.
As we know the FACH channel is mapped onto S-CCPCH channel which, according to 3GPP TS 25.211 subclause 5.3.3.4 Table 18
S-CCPCH channel has different types of slots which can change the channel rate, thus increasing the SCCPCH ch rate.

I am wondering if we chose a different slot, will this increase the FACH channel rate (to the theoretical max speed of 32kbps)? (I also have in mind that FACH ch rate also depends on fach/pch multiplexing/scheduling. I do also know that changing the slot might not be a good idea due to interoperability with terminals).

I cannot find any information about this. Could you help?


Thank you!

[mirc84]

Nobody knows?

If you do some calculations you may get the following (Bandwidth = (TbSize*TbNum*1000)/(TTI*8))
TB size TB num TTI IUB Bw (bps)
RACH 360 1 20 2250
PCH 240 1 10 3000
FACH 2sccpch 360 1 10 4500
FACH 1sccpch 168 1 10 2100

If using a different TFS for 2sccpch implementation increases the bw to 4.5 kbps, is there any measure to increase the channel rate to 32kbps (as specified by therory)?