During re-establishment we still have a valid SIB1 so we don't decode it
again. Then the UE never moves out of UE_RECEIVING_SIB, making
re-establishment impossible. This fixes addresses this.
Fixes: 11b87d8744 ("NR UE: RRC layer now explicitly tells MAC layer
when the RA procedure can be started)"
[E2 agent] Multi RC REPORT service styles support
Issue: unforeseen capability of having the same RAN Parameter ID across
different REPORT service styles.
Solution: keep only RAN Parameter IDs from REPORT styles that are
supported by OAI. Implement sequence array where each element is
combination of RIC request ID (unique per RIC SUBSCRIPTION) and Event
Trigger Definition. This way we can properly check further conditions
for a certain RAN Parameter ID. (e.g. if xApp is subscribed to RRC
Connected and/or other modes, for "RRC State Changed To" RAN Parameter
ID)
Next steps: for new RAN Parameter ID, add new sequence array.
Issue: unforeseen capability of having the same RAN Parameter ID across different
REPORT service styles.
Solution: keep only RAN Parameter IDs from REPORT styles that are supported by OAI.
Implement sequence array where each element is combination of RIC request ID (unique per RIC SUBSCRIPTION)
and Event Trigger Definition. This way we can properly check further conditions for a certain RAN Parameter ID.
(e.g. if xApp is subscribed to RRC Connected and/or other modes, for "RRC State Changed To" RAN Parameter ID)
Next steps: for new RAN Parameter ID, add new sequence array.
Co-authored-by: Bischoff <tano.bischoff@hhi.fraunhofer.de>
Co-authored-by: Shrinish Donde <shrinish.donde@hhi.fraunhofer.de>
Co-authored-by: Khanh Toan Pham <khanh.toan.pham@hhi.fraunhofer.de>
fix NTN LEO scenarios
- gNB: add support for NTN parameter ta-CommonDrift-r17
- NR UE: fix application of NTN TA information
- NR UE: add command line parameter ntn-initial-time-drift to compensate
time drift during initial sync
- NR UE: fix writeTimestamp inconsistencies
- NR UE: add MAC state UE_RECEIVING_SIB ensuring to start RA only after
successfully receiving SIBs
- rfsimulator: update earth radius for LEO simulation to match UE
position in ue.conf file
- update conf files for NTN LEO scenario
- update description how to run NTN scenarios in RUNMODEM.md
- fix: ta-Common is a round-trip-time, not a one-way delay
- NR UE: simplify calculation of next_tx_slot_and_frame by moving up
assignment of duration_rx_to_tx
- cellbarredNTN indicates notbarred in SIB1 if NTN access is available
- Removed b66 NTN and enabled B254 NTN conf file in CI
- NR UE: RRC layer now explicitly tells MAC layer when the RA procedure
can be started
- move NTN LEO config to band 254 and update doc/RUNMODEM.md
Closes#901
Refactor and extend NAS Registration Request
Extended NAS Registration Request generation and encoding according to
8.2.6 of 3GPP TS 24.501. Main topics:
- NAS Registration Type
- NAS KSI
- integrity protection
- NAS container encoding
Improvements:
- Add 5GMM Modes in NAS
- Introduced 5GMM state machine
Fixes:
- add 5GMM Capability IE to Registration Request
- closes#881, #819
The aggregation level search order for PDCCH candidates is modified:
- the search starts from desired_agg_level_index, which is a value from 0 to 4
proportial to pdcch_cl_adjust.
- pdcch_cl_adjust is a value between 0 and 1 that indicates PDCCH channel quality
by averaging HARQ DTX rate. A value of 0 means perfect channel, a value o 1 means
impaired channel.
E1AP enc/dec lib improvements
This MR is including some fixes and improvements for the E1AP library,
focusing mostly on Bearer Context Management:
- struct reorganization: split setup and modification request messages
into distinct structures, ensuring compliance with 3GPP TS 38.463
specifications
- add encoding/decoding sub-functions for different IEs
- improvements to Bearer Context Management: Implemented various
improvements to the E1 Bearer Context Setup Response and Request,
including the adoption of encoding/decoding sub-functions for
different IEs
- use lib functions whenever need (e.g. cp_bearer_context_setup_request
in cucp_cuup_e1ap.c)
- handle optional struct members as pointers
- updated copy/equality check utility functions
EDIT: The MR is also including the changes from !3222 (closed):
> While testing E1 with security enabled for DRBs, it was found that
> data traffic was not functional.
>
> The problem was that security settings were modified in the PDCP
> reestablishment happening when receiving Bearer Context Modification
> Request.
>
> So some restructuring was done.
>
> The actual fix is in 18176297, the others are for support. Basically
> we introduce a boolean to check if the security settings are present in
> Bearer Context Modification Request and we change PDCP security settings
> only if they are.
>
> (Note that in OAI CU security settings are not sent in Bearer Context
> Modification Request, so we could also remove all this, but we need to
> be compatible with other cu-up and/or cu-cp.)
Added Support of 35Mhz,45Mhz,70Mhz Bandwidth
Added Support of 35Mhz,45Mhz,70Mhz Bandwidth for 30Khz Subcarrier
Spacing, Also added 35Mhz, 45Mhz bw for 15Khz Subcarrierspacing.
Referred Spec TS 38.101 v18.6.0 section 5.3.2, table 5.3.2-1
Reset E1 UE contexts after E1 Setup Response
38.463 sec. 8.2.3 says
> This procedure also re-initialises the E1AP UE-related contexts (if
> any) and erases all related signalling connections in the two nodes
> like a Reset procedure would do.
Hence, delete all contexts after reception of E1 Setup Response. This
minimizes a risk of receiving an E1 bearer setup req for an existing UE,
which currently leads to an assert [we trust the CU-CP does not send the
same UE ID twice, as we only "mirror" the existing UE ID]. After this
MR, this is what happens if these entities fail:
- CU-CP fails: all context lost implicitly, upon reconnection, both DU
and CU-UP reset all contexts (like "start from zero")
- DU fails: CU-CP triggers NGAP UE context release request immediately
(radio connection with UE lost), all UE contexts attached to this DU
cleared (like "start from zero" for affected DU)
- CU-UP fails: initially, nothing (UE has no user plane); upon
reconnection of CU-UP, CU-CP triggers NGAP UE context release request
(cause radio connection with UE lost) and sends F1 Reset to DU, all UE
contexts associated to this DU cleared (like "start from zero")
for the last case, a possible improvement could be to use the F1 Reset
message to only clear affected UE conetxts. I chose not to do this,
because this MR is very big now already, and possible "victim" UEs
that were not at that CU-UP will reconnect as well
In Bearer Context Modification Request, the security information
field is needed only if we change the PDCP algorithms/keys. Since we
don't, no need to pass it.
Let's keep the old code, maybe the current understanding of the
specifications is wrong.
If the Bearer Context Modification Request does not contain security
information, the PDCP entity shall keep the currently configured security
settings.
Passing -1 for ciphering_algorithm and integrity_algorithm is the way
to implement this logic.
Check if the IE is memory allocated to deal with presence/absence of this information
element in Bearer Context Modification Request and add encoding/decoding
in the code.
Note that for decoding the integrity settings may be absent, in which
case we consider NIA0 to be used (no integrity protection). To be refined
if needed.
And for encoding, we always encode integrity settings, even if it's NIA0.
May also be refined if needed.
This was not a big problem, but we were advertising wrong
algorithm and deriving keys using this wrong algorithm in case
DRB ciphering and/or integrity was not active. (Say SRBs
are configured with NIA2 but DRBs are configured without
integrity, we would advertise NIA2 and send the integrity
key derived for NIA2, instead of NIA0 for both.)
It was not a problem because in the PDU Session Resource To Setup
item, there is "securityIndication" which we use to effectively
activate/deactivate the ciphering and/or integrity.
But it did not look clean to see a SecurityInformation with
incorrect data when inspecting the message in wireshark.
So let's use the correct values.
We could also not include the SecurityInformation if both ciphering
and integrity are not used, and only include ciphering if integrity
is not used (because integrity settings are optional).
But then if only integrity is used, we still need to include
ciphering, setting algorithm to NEA0 (no ciphering), because
the ciphering settings are always included.
This logic is too complex, let's use the simple one to always
include SecurityInformation with NEA0 and/or NIA0 if ciphering
and/or integrity is not activated.
As in deba3ae066 ("Reset CU-UP E1 UE contexts after E1 Setup
Response"), the CU-CP should reset the E1 UE contexts after E1 Setup
Response. 38.463 sec. 8.2.3 says
> This procedure also re-initialises the E1AP UE-related contexts (if
> any) and erases all related signalling connections in the two nodes like
> a Reset procedure would do.
In the case of CU-CP, this is a bit more complicated. More precisely, we
need to wait for the CU-UP to be available again before informing the DU
about the loss (implemented via an F1 Reset message), because otherwise,
the UE might reconnect immediately, before the CU-UP is online again.
Hence, on connection loss, we mark affected UEs (by setting their E1
association ID to 0); as long as the CU-UP does not connect, nothing
will happen (but UEs don't have user plane). Upon CU-UP connecting
again, we request release of the UEs via NGAP (similarly to what is done
if the DU goes offline, see invalidate_du_connections()), free the UE
contexts locally, and send an F1 Reset message to the DU, because
38.473 sec 8.2.1.2.1 says
> a failure at the gNB-CU [...] has resulted in the loss of some or
> all transaction reference information [...] a RESET message shall be
> sent to the gNB-DU.
The core should accept and send an NGAP release command message; since
no UE contexts are to be found (already deleted), the CU-CP will just
send a release complete (together with some warnings).
It might be possible to more gracefully handle the situation (e.g., as
described in 38.401 section 8.9.5 "Change of gNB-CU-UP"), but
- we lack the PDCP SN exchange
- the current procedure has the advantage of being equivalent to
"restart of the entire gNB", with less downtown.
The next commit will use rrc_remove_ue() to delete a CU(-CP+-UP)
context. However, we don't send NGAP UE context release at that moment
(we will instead *request* the release); more generally, it's not clear
that every user of rrc_remove_ue() wants to actually send this message.
Hence, refactor the code by separately calling
rrc_gNB_send_NGAP_UE_CONTEXT_RELEASE_COMPLETE() where appropriate.
Bearer context setup request and modification request messages
differ in various IEs according to 9.2.2 of 3GPP TS 38.463, e.g.
the Bearer context setup request does not contain a list of
DRBs to modify and does not contain an UP TL configuration.
Thus, the goal of this commit is to split the setup request message
and the modification request into two different structs:
* adopt e1ap_bearer_mod_req_t where necessary (e.g. fill_e1_bearer_modif)
Also, reorganized existing struct members according to specs:
* remove irrelevant struct members from the setup request
* group members from the same IEs into structs
* set optional struct members IEs as pointers
* add and adopt enc/dec/cp/eq lib functions for single IEs
* add UP_TL_information_t struct with TEID and TL address info and adopt in stack
* use int instead of long for count types
* update the relevant copy/equality check utility functions
Extra:
* add a function to handle Security Information in RRC in the process
* add create_up_tl_info and adopt in unit tests
38.463 sec. 8.2.3 says
> This procedure also re-initialises the E1AP UE-related contexts (if
> any) and erases all related signalling connections in the two nodes like
> a Reset procedure would do.
Hence, delete all contexts after reception of E1 Setup Response. This
minimizes a risk of receiving an E1 bearer setup req for an existing UE,
which currently leads to an assert [we trust the CU-CP does not send the
same UE ID twice, as we only "mirror" the existing UE ID].
* Without a valid 5G NAS security context:
* Send REGISTRATION REQUEST with cleartext IEs only.
* After activating a security context via Security Mode Control:
wrap the entire REGISTRATION REQUEST (with both non-cleartext and cleartext)
in a NAS message container IE, include it in SECURITY MODE COMPLETE
* With a valid 5G NAS security context:
* If non-cleartext IEs are needed, wrap the entire message in a NAS message container IE and cipher it.
* If only cleartext IEs are needed, send the message directly without the NAS message container IE.
Francesco Mani