Changed data structures for TBF and PDCH instances, to allow multislot

The new data structure is required to define slot/TFI assigment for MS
with multislot capability.

Now there are two lists for TBFs: uplink and downlink. It is possible to
have different TBFs with same TFI in the same direction, as long as they
are assigned on different timeslots.

See tbf.txt for description.

Note: This does not implement any multislot support. It defines the new
data structure. Currently only the first slot is assigned.

1 files changed, 30 insertions, 0 deletions

diff --git a/src/tbf.txt b/src/tbf.txt
index 3c06b39c..57254ea3 100644
--- a/src/tbf.txt
+++ b/src/tbf.txt
@@ -109,3 +109,33 @@ Polling:
    - The received frame is bad (BFI).
    - The GSM indicates that the block should have been already received.
 
+Data structures of TBFs and PDCHs:
+
+  There is a global structure for BTS.
+
+  The BTS structure has 8 TRX structures.
+
+  Each TRX structure has 8 PDCH structures, one for each timeslot.
+
+  There are two linked lists of TBF instances:
+   - uplink TBFs
+   - downlink TBFs
+
+  Each TBF instance also has:
+   - a direction
+   - a TFI of range 0..31
+   - an array of 8 PDCH structures, one for each assigned timeslot
+   - in case of uplink TBF: an array of 8 USFs, one for each assigned timeslot
+
+  Each PDCH structure also has:
+   - an array of 32 uplink TBFs that are assigned to this PDCH
+   - an array of 32 downlink TBFs that are assigned to this PDCH
+
+  On creation of a new TBF, it links to all assigned PDCHs.
+  Each PDCH links to that TBF. The TBF is added to the list of TBFs.
+  In case of uplink TBF: The allocated USFs are stored for each timeslot.
+
+  On release of a TBF, the link to this PDCH is removed from all assigned
+  PDCHs. The TBF is removed from the list of TBFs. The TBF is destroyed.
+
+