- This topic has 4 replies, 1 voice, and was last updated 13 years, 3 months ago by fedem.
9th October 2008 at 07:58 #54087fedemGuest
checking the table 5 clause 7 spec 45.002 (3GPP), they say that we can configure the CCCH downlink blocks mixing BCCH/AGCH/PCH.
That’s ok … but … a couple of options have no blocks at all for AGCH. It seems that only BCCH and PCH are present in these cases. How can it possible ? How can the MS receive the ImmediateAssignment ?
thanks in advance to clarify that.
fedem9th October 2008 at 11:48 #54088pixGuest
that’s too strange to be true 🙂 actually, it’s possible to allocate AGCH dynamically. In case there is no AGCH traffic at all, it might be possible that the BCCH does not carry any AGCH.
pix9th October 2008 at 13:08 #54089fedemGuest
thanks pix for your reply.9th October 2008 at 13:09 #54090MicheleGuest
It’s possible to configure the number of blocks reserved for AGCH (only used for immediate assignment handling) and the remaining CCCH blocks of the multiframe 51 (9 – num_AGCH – eventually BCCH) can be used for PCH.
But speaking about PCH blocks is the same as AGCH, in fact in case there is no any PCH block to send on air, a check about the presence of Immediate Assignments pending is performed.
It’s however reccomended to set at least an AGCH block.9th October 2008 at 14:31 #54091fedemGuest
yes, this sounds good.
Now I’ve found this in 44.018 (par.126.96.36.199.3.1):
The network may allocate a dedicated channel to the mobile station by sending an IMMEDIATE ASSIGNMENT
message or IMMEDIATE ASSIGNMENT EXTENDED message in unacknowledged mode on the same CCCH
timeslot on which it has received the CHANNEL REQUEST. There is no further restriction on what part of the
downlink CCCH an IMMEDIATE ASSIGNMENT message or IMMEDIATE ASSIGNMENT EXTENDED message
can be sent.
So it seems that there is no a strict rule about CCCH blocks definition, except for some scheduling of some basic sysinfos.
grazie e ciao 🙂