RRCTL is a simple protocol (inspired by Osmocom's L1CTL) that allows
an external NAS entity to control the RRC layer of srsUE. The most
notable primitives are PLMN search, selection, and PDU transfer.
The protocol assumes traditional master-slave communication, where
one side (an external NAS entity) initiates various processes,
while the other (srsUE) executes them and indicates the outcome.
Each RRCTL message starts with a header that can be defined as follows:
+-------------------------------+--------------------------+
| Message type | 6 bits |
+-------------------------------+--------------------------+
| Message sub-type | 2 bits |
+-------------------------------+--------------------------+
| Spare (RFU) | 8 bits |
+-------------------------------+--------------------------+
| Payload length | 2 octets (big endian) |
+-------------------------------+--------------------------+
| Payload (optional) | (see payload length) |
+-------------------------------+--------------------------+
The following message types are defined at the moment:
- RRCTL_RESET - reset internal state of the external NAS interface
(does nothing for now, may be useful in the future);
- RRCTL_PLMN_SEARCH - initiates PLMN (carrier) search on pre-configured
EARFCN (Absolute Radio Freqency Number);
- RRCTL_PLMN_SELECT - binds the UE to one of the previously detected
carriers (see RRCTL_PLMN_SEARCH) defined by a
given pair of MCC and MNC;
- RRCTL_CONN_ESTABLISH - establishes connection to the serving cell
(previously selected using RRCTL_PLMN_SELECT)
with a given cause and NAS PDU;
- RRCTL_CONN_RELEASE - releases previously established dedicated connection
(currently does nothing because the RRC layer does
not expose any API for that);
- RRCTL_DATA - encapsulates a received (Downlink) or to be transmitted
(Uplink) NAS PDU (the former also contains LCID).
Each message type has at least two of the following sub-types:
- RRCTL_REQ - request (usually comes from an external NAS entity),
used to initiate some process (e.g. PLMN search);
- RRCTL_IND - indication that something has happened without a prior
request (for example, a Downlink NAS PDU was received);
- RRCTL_CNF - confirmation (positive conslusion) of the requested task;
- RRCTL_ERR - negative conslusion of the requested task (error).
The protocol definition (enums ans structs) and codec functions are
defined in a separate namespaces: 'rrctl::proto' and 'rrctl::codec'
respectively. The codec functions may throw exceptions of type
'rrctl::codec::error' if something goes wrong.
This function does not modify the input buffer. Let's make it
possible to pass 'const uint8_t *' pointers without loosing
the const qualifier and making GCC unhappy.
This function does not modify any fields of the structure. Without
the 'const' qualifier it's impossible to call to_number() through
a const pointer of type 'struct plmn_id_t'.
reported/provided by user softdev86 in https://github.com/srsLTE/srsLTE/issues/566
author tested with local 4 port cell. I am not able to verify locally but
it looks ok, we'll revise later if needed.
When using srsLTE with Lime devices, calibration was performed before any configuration steps have happened, thus making calibration values invalid. Removing Lime specific calibration step from rf_soapy_imp makes so that devices will be automatically calibrated by SoapyLMS on rf_soapy_start_stream call.
Tested and working with srsENB using LimeSDR-USB v1.4 and LimeSDR-Mini v1.2 boards.
when the default RF args are used, NULL is passed as argument
to the RF driver. In this case, we should use the previous
SoapySDRDevice_enumerate() and let Soapy pick the device
when releasing PUCCH/SRS (see 5.3.13 in 36.331) we need to reset the SR config as well.
In our case, SR is handled by MAC so we need to (re-)configure MAC, not all of
MAC though, just SR.
- s1 handover composite state simplified
- the eNB now starts a HO cancellation when it receives an invalid
Handover Command
- the FSM log now prints the current state when it receives an unhandled
event
This patch adds version string to the 'libsrslte_rf' library.
This results in the library being built as
libsrslte_rf.so.20.04.2
with the following symbolic links
libsrslte_rf.so.0 -> libsrslte_rf.so.20.04.2
libsrslte_rf.so -> libsrslte_rf.so.0
The SRSLTE_SOVERSION variable should be increased with each backwards
incompatible change of the library.
Signed-off-by: Jan Remes <jan.remes@invasys.com>
Vadim Yanitskiy