tbf: Use TLLI as ID if TFI not yet assigned
Currently the old TFI is always used as ID when a
PACKET DOWNLINK ASSIGNMENT is generated. This fails
if the old TBF has not been fully assigned yet. The
MS will then ignore the PDA.
This commit changes write_packet_downlink_assignment to accept
an additional parameter old_tfi_is_valid and uses the new TBF's
TLLI instead of the olf TFI if that parameter is set to false.
Sponsored-by: On-Waves ehf
diff --git a/src/encoding.cpp b/src/encoding.cpp
index a5e5064..9471fff 100644
--- a/src/encoding.cpp
+++ b/src/encoding.cpp
@@ -274,8 +274,9 @@
/* generate downlink assignment */
void Encoding::write_packet_downlink_assignment(RlcMacDownlink_t * block,
- uint8_t old_tfi, uint8_t old_downlink, struct gprs_rlcmac_tbf *tbf,
- uint8_t poll, uint8_t rrbp, uint8_t alpha, uint8_t gamma, int8_t ta_idx,
+ bool old_tfi_is_valid, uint8_t old_tfi, uint8_t old_downlink,
+ struct gprs_rlcmac_tbf *tbf, uint8_t poll, uint8_t rrbp,
+ uint8_t alpha, uint8_t gamma, int8_t ta_idx,
uint8_t ta_ts, bool use_egprs)
{
// Packet downlink assignment TS 44.060 11.2.7
@@ -295,9 +296,14 @@
block->u.Packet_Downlink_Assignment.Exist_PERSISTENCE_LEVEL = 0x0; // PERSISTENCE_LEVEL: off
- block->u.Packet_Downlink_Assignment.ID.UnionType = 0x0; // TFI = on
- block->u.Packet_Downlink_Assignment.ID.u.Global_TFI.UnionType = old_downlink; // 0=UPLINK TFI, 1=DL TFI
- block->u.Packet_Downlink_Assignment.ID.u.Global_TFI.u.UPLINK_TFI = old_tfi; // TFI
+ if (old_tfi_is_valid) {
+ block->u.Packet_Downlink_Assignment.ID.UnionType = 0x0; // TFI = on
+ block->u.Packet_Downlink_Assignment.ID.u.Global_TFI.UnionType = old_downlink; // 0=UPLINK TFI, 1=DL TFI
+ block->u.Packet_Downlink_Assignment.ID.u.Global_TFI.u.UPLINK_TFI = old_tfi; // TFI
+ } else {
+ block->u.Packet_Downlink_Assignment.ID.UnionType = 0x1; // TLLI
+ block->u.Packet_Downlink_Assignment.ID.u.TLLI = tbf->tlli();
+ }
block->u.Packet_Downlink_Assignment.MAC_MODE = 0x0; // Dynamic Allocation
block->u.Packet_Downlink_Assignment.RLC_MODE = 0x0; // RLC acknowledged mode