Is someone could tell me, in which logical channel is first allocated the TFI
I am a little confuse about the first steps.
tell me if am right
Mobile receive his PTMISI in PCH of the CCCH
The mobile use RACH to answer and ask for a logical channel to communicate
in AGCH the information of the PDCH
(TS number and frequency) is given
and perhaps its TFI ?
unless the info of PDCH is already given in SI in BCCH
but I doubt that TFI is given in PACCH because in order to collect the info in PDCH we need the TFI
So for me TFI should be allocated in AGCH or PCH
but I need a confirmation
thank you very much
Logical channels are easy to understand once you try to put yourself in their shoes 🙂
Paging for GPRS is always the routing area (RA), defined by the couple Location Area Code (LAC) + Routing Area Code (RAC).
Most operators define RAC=0, so that there is only one RA per LA. This is sufficient in networks with low PS paging. Nowadays though, there might be a need to split 1 LA in 3 or 4 RA because there is heavy PS Paging generated by smartphones apps.
For example :