this is a rather large commit that is hard to split because
it touches quite a few components.
It's a preparation patch for adding NR split bearers in the next
step.
We realized that managing RLC and PDCP bearers for both NR and LTE
in the same entity doesn't work. This is because we use the LCID
as a key for all accesses. With NR dual connectivity however we
can have the same LCID active at the same time for both LTE and NR
carriers.
The patch solves that by creating a dedicated NR instance for RLC/PDCP
in the stack. But then the question arises for UL traffic on, e.g. LCID 4
what PDCP instance the GW should use for pushing SDUs. It doesnt' know
that. And in fact it doesn't need to. It just needs to know EPS
bearer IDs. So the next change was to remove the knowledge of what
LCIDs are from the GW. Make is agnostic and only work on EPS bearer IDs.
The handling and mapping between EPS bearer IDs and LCIDs for LTE
or NR (mainly PDCP for pushing data) is done in the Stack because
it has access to both.
The NAS also has a EPS bearer map but only knows about default and
dedicated bearers. It doesn't know on which logical channels they
are transmitted.
this commit adds a complete DL HARQ entity to the MAC of the UE.
It also refactors demux into an own class and adapts the PHY-MAC
interface to use the new MAC capabilities.
inspired by accepted (but not yet merged) PR to include the
(unique_)byte_buffer_t for MAC/PHY interfacing, this patch adds
a few more useful bits to that. Buffer management for UL data is now
done in MAC and only a pointer to the data is passed in the UL action.
* Move Tx softbuffer to MAC (until UL HARQ class is ready)
* Remove temparal data member in cc_worker
* Remove memcpy after packing MAC PDU
after adding the thread-safe PCAP writer functionality to the EUTRA
MAC object it became clear that we don't wont to replicate the
same for the NR object.
This patch therefore refactors the class that now supports both EUTRA and
NR rats. The old mac_nr_pcap.[h/cc] has been deleted. All test-cases
and usages now use the new object that needs to pass the RAT type in
the ctor.
this patch addresses the last open point of #2160
this patch refactors the SDU queuing and dropping policy of the RLC and PDCP layer.
the previous design had issues when packets have been generated at a higher
rate above the PDCP than they could be consumed below the RLC.
When the RLC SDU queues were full, we allowed two policies, one to block on the write
and the other to drop the SDU. Both options are not ideal because they either
lead to a blocking stack thread or to lost PDCP PDUs.
To avoid this, this patch makes the following changes:
* PDCP monitors RLC's SDU queue and drops packets on its north-bound SAP if queues are full
* a new method sdu_queue_is_full() has been added to the RLC interface for PDCP
* remove blocking write from pdcp and rlc write_sdu() interface
* all writes into queues need to be non-blocking
* if Tx queues are overflowing, SDUs are dropped above PDCP, not RLC
* log warning if RLC still needs to drop SDUs
* this case should be avoided with the monitoring mechanism
Andre Puschmann
Xavier Arteaga
Codebot
Francisco
David Rupprecht
faluco
Pedro Alvarez
Ismael Gomez
Francisco Paisana