osmo-pcu

Commit Graph

Author	SHA1	Message	Date
Daniel Willmann	efd5dbb168	tbf: Handle DL ACK/NACK poll timeout correctly If the PCU didn't receive the downlink ack/nack when it was polled there is no reason to assume it will arrive at a later time. In that case N3105 is already increased, but the next block sent should have a valid RRBP set as well to poll again. This can happen if either the BSN with the valid RRBP gets lost on the downlink or the DL ACK/NACK gets lost on the uplink path. Ticket: SYS#382 Sponsored-by: On-Waves ehf	2014-09-10 19:19:58 +02:00
Daniel Willmann	e481815583	tbf,bts: Keep track of new TBF for dl/ul assignment in m_new_tbf There are a couple of possibilities where one TBF is used to assign a new one: 1. Assign a DL TBF from a UL TBF 2. Assign a UL TBF from a DL TBF 3. Assign a DL TBF from a DL TBF which is in wait-release state (T3193 is running) In these cases the assignment is sent on the existing TBF and triggers the assignement of the new TBF (with different TFI/direction). The current code detects these situations by looking at dl/ul_ass_state and then chosing the TBF with the opposite direction (DL/UL) that has the same TLLI. This does not work in the case 3 above where a new DL TBF is triggered for a DL TBF. The current code reuses the old TBF (and TFI), but this violates the spec. This patch introduces a m_new_tbf member which is set to the new TBF to be assigned. When receiving a control ack the code looks up the n_new_tbf member of the tbf that requested the control ack and completes the ul/dl assignment. If the old TBF was in the wait release state (T3193 is running) it is released. From 3GPP TS 04.60 9.3.2.6: """ If the network has received the PACKET DOWNLINK ACK/NACK message with the Final Ack Indicator bit set to '1' and has new data to transmit for the mobile station, the network may establish a new downlink TBF for the mobile station by sending the PACKET DOWNLINK ASSIGNMENT or PACKET TIMESLOT RECONFIGURE message with the Control Ack bit set to '1' on PACCH. In case the network establishes a new downlink TBF for the mobile station, the network shall stop timer T3193. """ reuse_tbf() is modified to allocate a new TBF with a new TFI and trigger a dl assignment for that TBF on the old TBF. All pending data is moved to the new TBF. Ticket: SYS#382 Sponsored-by: On-Waves ehf	2014-09-10 19:04:46 +02:00
Daniel Willmann	ca102af92b	tbf: Split out UL/DL TBF methods into separate files tbf_ul.cpp for UL TBF methods tbf_dl.cpp for DL TBF methods This commit contains no code changes. Ticket: SYS#389 Sponsored by: On-Waves ehf	2014-08-12 19:24:49 +02:00

Author

SHA1

Message

Date

Daniel Willmann

efd5dbb168

tbf: Handle DL ACK/NACK poll timeout correctly

If the PCU didn't receive the downlink ack/nack when it was polled there
is no reason to assume it will arrive at a later time. In that case
N3105 is already increased, but the next block sent should have a valid
RRBP set as well to poll again.
This can happen if either the BSN with the valid RRBP gets lost on the
downlink or the DL ACK/NACK gets lost on the uplink path.

Ticket: SYS#382
Sponsored-by: On-Waves ehf

2014-09-10 19:19:58 +02:00

Daniel Willmann

e481815583

tbf,bts: Keep track of new TBF for dl/ul assignment in m_new_tbf

There are a couple of possibilities where one TBF is used to assign a
new one:

1. Assign a DL TBF from a UL TBF
2. Assign a UL TBF from a DL TBF
3. Assign a DL TBF from a DL TBF which is in wait-release state (T3193 is
   running)

In these cases the assignment is sent on the existing TBF and triggers
the assignement of the new TBF (with different TFI/direction).

The current code detects these situations by looking at dl/ul_ass_state
and then chosing the TBF with the opposite direction (DL/UL) that has
the same TLLI. This does not work in the case 3 above where a new DL TBF
is triggered for a DL TBF. The current code reuses the old TBF (and
TFI), but this violates the spec.

This patch introduces a m_new_tbf member which is set to the new TBF to
be assigned. When receiving a control ack the code looks up the
n_new_tbf member of the tbf that requested the control ack and completes
the ul/dl assignment. If the old TBF was in the wait release state
(T3193 is running) it is released.

From 3GPP TS 04.60 9.3.2.6:
"""
If the network has received the PACKET DOWNLINK ACK/NACK message with
the Final Ack Indicator bit set to '1' and has new data to transmit for
the mobile station, the network may establish a new downlink TBF for the
mobile station by sending the PACKET DOWNLINK ASSIGNMENT or PACKET
TIMESLOT RECONFIGURE message with the Control Ack bit set to '1' on
PACCH. In case the network establishes a new downlink TBF for the mobile
station, the network shall stop timer T3193.
"""

reuse_tbf() is modified to allocate a new TBF with a new TFI and trigger
a dl assignment for that TBF on the old TBF. All pending data is moved
to the new TBF.

Ticket: SYS#382
Sponsored-by: On-Waves ehf

2014-09-10 19:04:46 +02:00

Daniel Willmann

ca102af92b

tbf: Split out UL/DL TBF methods into separate files

tbf_ul.cpp for UL TBF methods
tbf_dl.cpp for DL TBF methods

This commit contains no code changes.

Ticket: SYS#389
Sponsored by: On-Waves ehf

2014-08-12 19:24:49 +02:00

3 Commits