Merge remote-tracking branch 'origin/739-rf-channel-sim-improvements' into integration_2024_w09

common/utils/telnetsrv/DOC/telnetarch.md

@@ -21,11 +21,11 @@ The telnet server provides an API which can be used by any oai component to add
 
 telnet server source files are located in [common/utils/telnetsrv](https://gitlab.eurecom.fr/oai/openairinterface5g/tree/develop/common/utils/telnetsrv)
 
-1. [telnetsrv.c](https://gitlab.eurecom.fr/oai/openairinterface5g/tree/develop/common/utils/telnetsrv/telnetsrv.c) contains the telnet server implementation, including the implementation of the `telnet` CLI command. This implementation is compatible with all softmodem executables and is in charge of loading any additional `libtelnetsrv_<app> .so` containing code specific to the running executables.
-1.  [telnetsrv.h](https://gitlab.eurecom.fr/oai/openairinterface5g/tree/develop/common/utils/telnetsrv/telnetsrv.h) is the telnet server include file containing both private and public data type definitions. It also contains API prototypes for functions that are used to register a new command in the server.
+1. [telnetsrv.c](../telnetsrv.c) contains the telnet server implementation, including the implementation of the `telnet` CLI command. This implementation is compatible with all softmodem executables and is in charge of loading any additional `libtelnetsrv_<app> .so` containing code specific to the running executables.
+1.  [telnetsrv.h](../telnetsrv.h) is the telnet server include file containing both private and public data type definitions. It also contains API prototypes for functions that are used to register a new command in the server.
 1.  `telnetsrv_<XXX\>.c`: implementation of \<XXX\> CLI command which are delivered with the telnet server and are common to all softmodem executables. 
 1. `telnetsrv_<XXX\>.h`: include file for the implementation of XXX CLI command. Usually included only in the corresponding `.c`file
 1.  `telnetsrv_<app>_<XXX>.c`: implementation of \<XXX\> CLI command specific to the executable identified by \<app\>.These sources are used to create `libtelnetsrv_<app>.so` at build time.
-1.  [telnetsrv_CMakeLists.txt](https://gitlab.eurecom.fr/oai/openairinterface5g/blob/develop/common/utils/telnetsrv/telnetsrv_CMakeLists.txt): CMakelists file containing the cmake instructions to build the telnet server. this file is included in the [global oai CMakelists](https://gitlab.eurecom.fr/oai/openairinterface5g/blob/develop/cmake_targets/CMakeLists.txt).
+1.  [telnetsrv_CMakeLists.txt](../CMakeLists.txt): CMakelists file containing the cmake instructions to build the telnet server. this file is included in the [global oai CMakelists](../../../../cmake_targets/CMakeLists.txt).
 
 [oai telnet server home](telnetsrv.md)

common/utils/telnetsrv/DOC/telnetusage.md

@@ -26,7 +26,7 @@ Below are  examples of telnet sessions:
 *  [measur command](telnetmeasur.md)
 
 # telnet server parameters
-The telnet server is using the [oai configuration module](Config/Rtusage). Telnet parameters must be specified in the `telnetsrv` section. Some parameters can be modified via the telnet telnet server command, as specified in the last column of the following table.
+The telnet server is using the [oai configuration module](../../../../common/config/DOC/config/rtusage.md). Telnet parameters must be specified in the `telnetsrv` section. Some parameters can be modified via the telnet telnet server command, as specified in the last column of the following table.
 
 | name | type | default | description | dynamic |
 |:---:|:---:|:---:|:----|:----:|

doc/README.md

@@ -43,6 +43,7 @@ There is some general information in the [OpenAirInterface Gitlab Wiki](https://
 - [How to run a 5G-NSA setup](./TESTING_GNB_W_COTS_UE.md)
 - [How to run a 4G setup using L1 simulator](./L1SIM.md) _Note: we recommend the RFsimulator_
 - [How to use the L2 simulator](./L2NFAPI.md)
+- [How to use the OAI channel simulator](../openair1/SIMULATION/TOOLS/DOC/channel_simulation.md)
 - [How to use multiple BWPs](./RUN_NR_multiple_BWPs.md)
 - [How to run OAI-VNF and OAI-PNF](./RUN_NR_NFAPI.md) _Note: does not work currently_
 - [How to use the positioning reference signal (PRS)](./RUN_NR_PRS.md)

executables/lte-softmodem.h

@@ -170,9 +170,6 @@ extern void init_UE(int nb_inst,
 
 extern void init_thread(int sched_runtime, int sched_deadline, int sched_fifo, cpu_set_t *cpuset, char *name);
 
-extern void init_ocm(void);
-extern void init_ue_devices(PHY_VARS_UE *);
-
 PHY_VARS_UE *init_ue_vars(LTE_DL_FRAME_PARMS *frame_parms, uint8_t UE_id, uint8_t abstraction_flag);
 
 void init_eNB_afterRU(void);

executables/nr-softmodem.c

@@ -116,7 +116,6 @@ unsigned char NB_gNB_INST = 1;
 char *uecap_file;
 
 runmode_t mode = normal_txrx;
-static double snr_dB=20;
 
 #if MAX_NUM_CCs == 1
 rx_gain_t rx_gain_mode[MAX_NUM_CCs][4] = {{max_gain,max_gain,max_gain,max_gain}};

executables/nr-softmodem.h

@@ -28,7 +28,6 @@
   {"U" ,                    CONFIG_HLP_ULBM_PHYTEST,   0,                .u64ptr=&ulsch_slot_bitmap,          .defintval=0,                     TYPE_UINT64, 0},        \
   {"usrp-tx-thread-config", CONFIG_HLP_USRP_THREAD,    0,                .iptr=&usrp_tx_thread,               .defstrval=0,                     TYPE_INT,    0},        \
   {"uecap_file",            CONFIG_HLP_UECAP_FILE,     0,                .strptr=&uecap_file,                 .defstrval="./uecap_ports1.xml",  TYPE_STRING, 0},        \
-  {"s" ,                    CONFIG_HLP_SNR,            0,                .dblptr=&snr_dB,                     .defdblval=25,                    TYPE_DOUBLE, 0},        \
 }
 // clang-format on
 

openair1/PHY/TOOLS/calibration_test.c

@@ -14,7 +14,6 @@ int8_t threequarter_fs;
 uint64_t downlink_frequency[MAX_NUM_CCs][4];
 int32_t uplink_frequency_offset[MAX_NUM_CCs][4];
 int opp_enabled;
-static double snr_dB=20;
 THREAD_STRUCT thread_struct;
 uint32_t target_ul_mcs = 9;
 uint32_t target_dl_mcs = 9;

openair1/PHY/defs_L1_NB_IoT.h

@@ -551,9 +551,6 @@ typedef struct PHY_VARS_eNB_NB_IoT_s {
   int                           max_eNB_id, max_sync_pos;
   ///
   int                           N_TA_offset;                        ///timing offset used in TDD
-  /// \brief sinr for all subcarriers of the current link (used only for abstraction).
-  /// first index: ? [0..N_RB_DL*12[
-  double                        *sinr_dB;
   /// N0 (used for abstraction)
   double                        N0;
   ///
@@ -885,9 +882,6 @@ typedef struct {
   int              mac_enabled;
   /// Flag to initialize averaging of PHY measurements
   int              init_averaging;
-  /// \brief sinr for all subcarriers of the current link (used only for abstraction).
-  /// - first index: ? [0..12*N_RB_DL[
-  double           *sinr_dB;
   /// \brief sinr for all subcarriers of first symbol for the CQI Calculation.
   /// - first index: ? [0..12*N_RB_DL[
   double           *sinr_CQI_dB;

openair1/PHY/defs_UE.h

@@ -738,10 +738,6 @@ typedef struct {
   /// Flag to initialize averaging of PHY measurements
   int init_averaging;
 
-  /// \brief sinr for all subcarriers of the current link (used only for abstraction).
-  /// - first index: ? [0..12*N_RB_DL[
-  double *sinr_dB;
-
   /// \brief sinr for all subcarriers of first symbol for the CQI Calculation.
   /// - first index: ? [0..12*N_RB_DL[
   double *sinr_CQI_dB;

openair1/PHY/defs_eNB.h

@@ -616,10 +616,6 @@ typedef struct PHY_VARS_eNB_s {
   uint32_t max_peak_val;
   int max_eNB_id, max_sync_pos;
 
-  /// \brief sinr for all subcarriers of the current link (used only for abstraction).
-  /// first index: ? [0..N_RB_DL*12[
-  double *sinr_dB;
-
   /// N0 (used for abstraction)
   double N0;
 

openair1/PHY/defs_nr_UE.h

@@ -512,10 +512,6 @@ typedef struct PHY_VARS_NR_UE_s {
   /// Flag to initialize averaging of PHY measurements
   int init_averaging;
 
-  /// \brief sinr for all subcarriers of the current link (used only for abstraction).
-  /// - first index: ? [0..12*N_RB_DL[
-  double *sinr_dB;
-
   /// sinr_effective used for CQI calulcation
   double sinr_eff;
 

openair1/SIMULATION/TOOLS/DOC/arch.md

-# Channel simulation source files
-
-1. [random_channel.c](../random_channel.c) 
-1. [sim.h](../sim.h) 
-
-
-
-[channel simulation  main page](channel_simulation.md)
-[oai Wikis home](https://gitlab.eurecom.fr/oai/openairinterface5g/wikis/home)
\ No newline at end of file

openair1/SIMULATION/TOOLS/DOC/devusage.md

-### channel simulation  developer usage
-
-
-[Configuring the channel simulation](rtusage.md)
-
-[channel simulation main page](channel_simulation.md)
-[oai Wikis home](https://gitlab.eurecom.fr/oai/openairinterface5g/wikis/home)
\ No newline at end of file

openair1/SIMULATION/TOOLS/DOC/rtusage.md

-## configuring the channel simulation
-Oai channel simulation is using the [config module](../../../config/config.md) to get its parameters at init time. The [telnet server](../../telnetsrv/DOC/telnetsrv.md) includes a set of commands which can be used to dynamically modify some channel model parameters
-
-All channel simulation parameters are defined in the `channelmod` section. Most parameters are specific to a channel model and  are only used by the rfsimulator.
-
-### global parameters
-
-| name | type | default | description |
-|:---:|:---:|:---:|:----|
-| `max_chan` | integer | `25` | Maximum number of channel model that can be defined in the system. Must be greater than the number of model definitions  in the model list loaded at init time. |
-| `modellist` | character string | `DefaultChannelList` | Name of the channel models list to load at init time. |
-
-### Model lists
-
-Several model lists can be defined in the oai configuration file. One, defined by the `modellist` parameter is loaded at init time. In the configuration file each model list item describes a channel model using a group of parameters:
-
-| parameter name | type | default | description |
-|:---:|:---:|:---:|:----|
-| `model name` | character string | mandatory |name of the model, as used in the code to retrieve a model definition|
-| `type` |                  | `AWGN` | name of the channel modelization algorithm applied on rf signal. The list of available model types can be listed via the [telnet server](../../telnetsrv/DOC/telnetsrv.md) or by entering an invalid type name |
-| `ploss_dB` |   real (float)   |  | path loss of the channel, in dB |
-| `noise_power_dB` |  real (double)   |  | noise of the channel in dB |
-| `forgetfact` |  real (double)   |  |  |
-| `offset` |     integer      |  |  |
-| `ds_tdl` |   real double    |  |  |
-
-Channel simulation parameters can also be specified on the command line:
-
-```bash
-./lte-softmodem -O ../../../ci-scripts/conf_files/enb.band7.tm1.50prb.usrpb210.conf --noS1 --rfsim --rfsimulator.options chanmod --rfsimulator.serveraddr enb --telnetsrv --channelmod.modellist modellist_rfsimu_2 --channelmod.modellist_rfsimu_2.[1].offset 120
-```
-### Using the telnet server to modify channel simulator parameters
-The telnet server includes a `channelmod` command which can be used to dynamically modify some channel model parameters. This command is only available when channel simulation is enabled (via `rfsimulator.options chanmod` option when running the rfsimulator.  `channelmod` command has its own help:
-
-```
-$ telnet 127.0.0.1 9090
-Trying 127.0.0.1...
-Connected to 127.0.0.1.
-Escape character is '^]'.
- 
-softmodem_enb> help
-.....................................
-   module 6 = channelmod:
-      channelmod help 
-      channelmod show <predef,current>
-      channelmod modify <channelid> <param> <value>
-   module 7 = rfsimu:
-      rfsimu setmodel <model name> <model type>
-softmodem_enb> channelmod help
-channelmod commands can be used to display or modify channel models parameters
-channelmod show predef: display predefined model algorithms available in oai
-channelmod show current: display the currently used models in the running executable
-channelmod modify <model index> <param name> <param value>: set the specified parameters in a current model to the given value
-                  <model index> specifies the model, the show current model command can be used to list the current models indexes
-                  <param name> can be one of "riceanf", "aoa", "randaoa", "ploss", "noise_power_dB", "offset", "forgetf"
-softmodem_enb> 
-
-```
-
-
-
-
-
-
-
-The [rfsimulator documentation](../../../../radio/rfsimulator/README.md ) has also some specific information when using the channel simulation via this tool. 
-
-[channel simulation main page](channel_simulation.md)
-[oai Wikis home](https://gitlab.eurecom.fr/oai/openairinterface5g/wikis/home)

openair1/SIMULATION/TOOLS/random_channel.c

@@ -72,8 +72,6 @@ static telnetshell_cmddef_t channelmod_cmdarray[] = {
 
 static telnetshell_vardef_t channelmod_vardef[] = {{"", 0, 0, NULL}};
 
-static double snr_dB=25;
-static double sinr_dB=0;
 static unsigned int max_chan;
 static channel_desc_t **defined_channels;
 static char *modellist_name;
@@ -2261,14 +2259,6 @@ int modelid_fromstrtype(char *modeltype) {
   return modelid;
 }
 
-double channelmod_get_snr_dB(void) {
-  return snr_dB;
-}
-
-double channelmod_get_sinr_dB(void) {
-  return sinr_dB;
-}
-
 void init_channelmod(void) {
   paramdef_t channelmod_params[] = CHANNELMOD_PARAMS_DESC;
   int numparams = sizeofArray(channelmod_params);

openair1/SIMULATION/TOOLS/sim.h

@@ -264,8 +264,6 @@ typedef enum {
 #define CHANNELMOD_HELP_MODELLIST "<list name> channel list name in config file describing the model type and its parameters\n"
 // clang-format off
 #define CHANNELMOD_PARAMS_DESC {  \
-  {"s"      ,                     CONFIG_HLP_SNR,                     PARAMFLAG_CMDLINE_NOPREFIXENABLED,  .dblptr=&snr_dB,              .defdblval=25,                    TYPE_DOUBLE, 0}, \
-  {"sinr_dB",                     NULL,                               0,                                  .dblptr=&sinr_dB,             .defdblval=0 ,                    TYPE_DOUBLE, 0}, \
   {"max_chan",                    "Max number of runtime models",     0,                                  .uptr=&max_chan,              .defintval=10,                    TYPE_UINT,   0}, \
   {CHANNELMOD_MODELLIST_PARANAME, CHANNELMOD_HELP_MODELLIST,          0,                                  .strptr=&modellist_name,      .defstrval="DefaultChannelList",  TYPE_STRING, 0}, \
 }
@@ -302,18 +300,11 @@ typedef struct {
   double r_re_UL[NUMBER_OF_eNB_MAX][2][30720];
   double r_im_UL[NUMBER_OF_eNB_MAX][2][30720];
   int RU_output_mask[NUMBER_OF_UE_MAX];
-  int UE_output_mask[NUMBER_OF_RU_MAX];
   pthread_mutex_t RU_output_mutex[NUMBER_OF_UE_MAX];
   pthread_mutex_t UE_output_mutex[NUMBER_OF_RU_MAX];
-  pthread_mutex_t subframe_mutex;
-  int subframe_ru_mask;
-  int subframe_UE_mask;
   openair0_timestamp current_ru_rx_timestamp[NUMBER_OF_RU_MAX][MAX_NUM_CCs];
   openair0_timestamp current_UE_rx_timestamp[MAX_MOBILES_PER_ENB][MAX_NUM_CCs];
-  openair0_timestamp last_ru_rx_timestamp[NUMBER_OF_RU_MAX][MAX_NUM_CCs];
-  openair0_timestamp last_UE_rx_timestamp[MAX_MOBILES_PER_ENB][MAX_NUM_CCs];
   double ru_amp[NUMBER_OF_RU_MAX];
-  pthread_t rfsim_thread;
 } sim_t;
 
 

radio/rfsimulator/README.md

@@ -12,6 +12,29 @@ As much as possible, it works like an RF board, but not in real-time: It can
 run faster than real-time if there is enough CPU, or slower (it is CPU-bound
 instead of real-time RF sampling-bound).
 
+# Architecture
+
+High-level flowchart of the RF Simulator, including the channel simulation feature:
+
+```mermaid
+flowchart TD
+    subgraph ide1 [RX]
+    RU[ru_thread]-->|FH southbound|FH[rx_rf]
+    FH-->read
+    read -->|apply channel model|rxAddInput
+    end
+    subgraph ide2 [RFSim initialization]
+    A[load_lib] -->|load RFSIM lib| B[device_init]
+    B[device_init] -.-> |set trx_read_func|read[rfsimulator_read]
+    rxAddInput --> FH 
+    B -->cfg[rfsimulator_readconfig]
+    cfg -->|read RFSIM CL options|C{rfsimu_params}
+    C -->|chanmod|loadchannel[load_channellist]
+    C -->|saviq|E[saveIQfile]
+    loadchannel-->|new SCM|scm[new_channel_desc_scm]
+    end
+```
+
 # Build
 
 ## From [build_oai](../../../doc/BUILD.md) script
@@ -44,46 +67,19 @@ default the RF simulator device will try to connect to host 127.0.0.1, port
 have to pass `--rfsimulator.serveraddr server` on the command line, or specify
 the corresponding section in the configuration file.
 
-The RF simulator is using the configuration module, and its parameters are defined in a specific section called "rfsimulator".
-
-| parameter            | usage                                                                                                             | default |
-|:---------------------|:------------------------------------------------------------------------------------------------------------------|----:|
-| serveraddr           | ip address to connect to, or `server` to behave as a tcp server                                                      | 127.0.0.1 |
-| serverport           | port number to connect to or to listen on (eNB, which behaves as a tcp server)                                    | 4043 |
-| options              | list of comma separated run-time options, two are supported: `chanmod` to enable channel modeling and `saviq` to write transmitted iqs to a file | all options disabled  |
-| modelname            | Name of the channel model to apply on received iqs when the `chanmod` option is enabled                           | AWGN |
-| IQfile               | Path to the file to be used to store iqs, when the `saviq` option is enabled                                      | /tmp/rfsimulator.iqs |
+The RF simulator is using the configuration module, and its parameters are defined in a specific section called "rfsimulator". Add the following options to the command line in order to enable different RFSim features:
 
-## How to use the RF simulator options
+| CL option                       | usage                                                                          | default                |
+|:---------------------           |:-------------------------------------------------------------------------------|----:                   |
+|`--rfsimulator.serveraddr <addr>`| ip address to connect to, or `server` to behave as a tcp server                | 127.0.0.1              |
+|`--rfsimulator.serverport <port>`| port number to connect to or to listen on (eNB, which behaves as a tcp server) | 4043                   |
+| `--rfsimulator.options`         | list of comma separated run-time options, two are supported: `chanmod`, `saviq`| all options disabled   |
+| `--rfsimulator.options saviq`   | store IQs to a file for future replay                                          | disabled               |
+|`--rfsimulator.options chanmod`  | enable the channel model                                                       | disabled               |
+|`--rfsimulator.IQfile <file>`    | path to a file to store the IQ samples to (only with `saviq`)                  | `/tmp/rfsimulator.iqs` |
+|`--rfsimulator.wait_timeout`     | wait timeout when no UE is connected                                           | 1                      |
 
-To define and use a channel model, the configuration file needs to include a
-channel configuration file. To do this, add `@include "channelmod_rfsimu.conf"`
-to the end of the configuration file, and place the channel configuration file
-in the same directory. An example channel configuration file is
-[`ci-scripts/conf_files/channelmod_rfsimu.conf`](../../ci-scripts/conf_files/channelmod_rfsimu.conf).
-
-Add the following options to the command line to enable the channel model and the IQ samples saving for future replay:
-```bash
---rfsimulator.options chanmod,saviq
-```
-or just:
-```bash
---rfsimulator.options chanmod
-```
-to enable the channel model.
-
-set the model with:
-```bash
---rfsimulator.modelname AWGN
-```
-
-Example run:
-
-```bash
-sudo ./nr-softmodem -O ../../../targets/PROJECTS/GENERIC-LTE-EPC/CONF/gnb.band78.tm1.106PRB.usrpn300.conf --parallel-config PARALLEL_SINGLE_THREAD --rfsim --phy-test --rfsimulator.options chanmod --rfsimulator.modelname AWGN
-```
-
-where `@include "channelmod_rfsimu.conf"` has been added at the end of the file, and `ci-scripts/conf_files/channelmod_rfsimu.conf` copied to `targets/PROJECTS/GENERIC-LTE-EPC/CONF/`.
+Please refer to this document [`SIMULATION/TOOLS/DOC/channel_simulation.md`](../../openair1/SIMULATION/TOOLS/DOC/channel_simulation.md) for information about using the RFSimulator options to run the simulator with a channel model.
 
 ## 4G case
 
@@ -133,9 +129,9 @@ sudo ./nr-uesoftmodem --rfsim --phy-test --rfsimulator.serveraddr <TARGET_GNB_IP
 
 Notes:
 
-1. This starts the gNB and UE in the `phy-test` UP-only mode where the gNB is started as if a UE had already connected. See [RUNMODEM.md](../../doc/RUNMODEM.md) for more details.
+1. This starts the gNB and UE in the `phy-test` UP-only mode where the gNB is started as if a UE had already connected. See [`RUNMODEM.md`](../../doc/RUNMODEM.md) for more details.
 2. `<TARGET_GNB_IP_ADDRESS>` should be the IP interface address of the remote host running the gNB executable, if the gNB and nrUE run on separate hosts, or be omitted if they are on the same host.
-3. To enable the noS1 mode, `--noS1` option should be added to the command line, see again [RUNMODEM.md](../../doc/RUNMODEM.md).
+3. To enable the noS1 mode, `--noS1` option should be added to the command line, see again [`RUNMODEM.md`](../../doc/RUNMODEM.md).
 4. To operate the gNB/UE with a 5GC, start them using the `--sa` option. More information can be found [here](../../../doc/NR_SA_Tutorial_OAI_CN5G.md).
 
 ## Store and replay
@@ -152,65 +148,9 @@ The file format is successive blocks of a header followed by the I/Q array. If y
 
 The format intends to be compatible with the OAI store/replay feature on USRP.
 
-## Channel simulation
-
-When the `chanmod` option is enabled, the RF channel simulator is called.
-
-In the current version all channel parameters are set depending on the model name via a call to:
-```bash
-new_channel_desc_scm(bridge->tx_num_channels,
-                     bridge->rx_num_channels,
-                     <model name>,
-                     bridge->sample_rate,
-                     bridge->tx_bw,
-                     0.0, // forgetting_factor
-                     0,   // maybe used for TA
-                     0);  // path_loss in dB
-```
-Only the input noise can be changed on command line with the `-s` parameter.
-
-With path loss = 0 set `-s 5` to see a little noise. `-s` is a shortcut to `channelmod.s`. It is expected to enhance the channel modelization flexibility by the addition of more parameters in the channelmod section.
+## How to use OAI RFSIM with a channel model
 
-Example to add a very small noise:
-```bash
--s 30
-```
-to add a lot of noise:
-```bash
--s 5
-```
-
-Example run commands:
-```bash
-sudo ./nr-softmodem -O ../../../targets/PROJECTS/GENERIC-LTE-EPC/CONF/gnb.band78.tm1.106PRB.usrpn300.conf --parallel-config PARALLEL_SINGLE_THREAD --rfsim --phy-test --rfsimulator.options chanmod --rfsimulator.modelname AWGN
-
-```
-# Real time control and monitoring
-
-Add the `--telnetsrv` option to the command line. Then in a new shell, connect to the telnet server, example:
-```bash
-telnet 127.0.0.1 9090
-```
-once connected it is possible to monitor the current status:
-```bash
-channelmod show current
-```
-
-see the available channel models:
-```bash
-channelmod show predef
-```
-
-or modify the channel model, for example setting a new model:
-```bash
-rfsimu setmodel AWGN
-```
-setting the pathloss, etc...:
-```bash
-channelmod modify <channelid> <param> <value>
-channelmod modify 0 ploss 15
-```
-where `<param>` can be one of `riceanf`, `aoa`, `randaoa`, `ploss`, `offset`, `forgetf`.
+Please refer to this document [`channel_simulation.md`](../../openair1/SIMULATION/TOOLS/DOC/channel_simulation.md) to get familiar with channel simulation in RFSIM and to see the list of commands for real-time usage with telnet.
 
 # Caveats
 

radio/rfsimulator/simulator.c

@@ -206,17 +206,6 @@ static int allocCirBuf(rfsimulator_state_t *bridge, int sock)
 
   if ( bridge->channelmod > 0) {
     // create channel simulation model for this mode reception
-    // snr_dB is pure global, coming from configuration paramter "-s"
-    // Fixme: referenceSignalPower should come from the right place
-    // but the datamodel is inconsistant
-    // legacy: RC.ru[ru_id]->frame_parms.pdsch_config_common.referenceSignalPower
-    // (must not come from ru[]->frame_parms as it doesn't belong to ru !!!)
-    // Legacy sets it as:
-    // ptr->channel_model->path_loss_dB = -132.24 + snr_dB - RC.ru[0]->frame_parms->pdsch_config_common.referenceSignalPower;
-    // we use directly the paramter passed on the command line ("-s")
-    // the value channel_model->path_loss_dB seems only a storage place (new_channel_desc_scm() only copy the passed value)
-    // Legacy changes directlty the variable channel_model->path_loss_dB place to place
-    // while calling new_channel_desc_scm() with path losses = 0
     static bool init_done=false;
 
     if (!init_done) {