<center><i class="fa fa-edit"></i> FlexRIC RIC implementation </center>

:::warning # <center><i class="fa fa-edit"></i> FlexRIC RIC implementation </center> ::: ###### tags: `FlexRIC` `TEEP` `Internship` :::success **Learning Objective:** The study objectives were to: - Explore files, structures and functions of RIC module - Understand the meaning of the files - Understand the connection of RIC to other modules ::: [TOC] ## Module 8: FlexRIC RIC implementation RIC, or Server Library, is the third module of FlexRIC. It contains iApps and the interface for connection to xApps. ![](https://i.imgur.com/s0kVlfe.png) ## 1. Source files of RIC implementation ``` ric ├── asio_ric.h ├── e2ap_ric.h ├── e2_node.h ├── endpoint_ric.h ├── iApps │ ├── influx.h │ ├── nng │ │ ├── keep_alive │ │ │ └── keep_alive_timer.h │ │ ├── msgs │ │ │ └── xapp_msgs.h │ │ ├── notify_nng_listener.h │ │ └── req_reply.h │ ├── redis.h │ ├── stdout.h │ └── string_parser.h ├── msg_handler_ric.h ├── near_ric_api.h ├── near_ric.h └── plugin_ric.h ``` |File | Function | Remarks | |---- | -------- | ------- | |[asio_ric.h](#211-asio_rich)|Asyn. IO|| |[e2ap_ric.h](#212-e2ap_ric.h)|E2AP|Encode/decode E2 MSG| |[e2_node.h](#213-e2_node.h)|E2 Node structure|| |[endpoint_ric.h](#214-endpoint_ric.h)|Endpoint|| |[msg_handler_ric.h](#2113-msg_handler_ric.h)|MSG Handler|Agent MSG Handlers| |[near_ric_api.h](#214-near_ric_api.h)|API to Near-RIC|| |[near_ric.h](#215-near_ric.h)|Main Near-RIC functionality|Event loop| |[plugin_ric.h](#216-plugin_ric.h)|SM Plugins|| |[influx.h](#215-influx.h), [redis.h](#216-redis.h), [stdout.h](#217-stdout.h) and [notify_nng_listener.h](#218-notify_nng_listener.h)|Listeners|Receive notifications from RIC Events and transfer it to InfluxDB, Redis, NNG or output| |[string_parser.h](#2112-string_parser.h)|Converts MAC, RLC, PDCP, Slice stats to string.|| |[req_reply.h](#2111-req_reply.h)|Request NNG reply from xApps|Runs in a separate thread| |[keep_alive_timer.h](#219-keep_alive_timer.h)|Timer|| |[xapp_msgs.h](#2110-xapp_msgs.h)|Typedefs of NNG xApps messages|| ## 2. FlexRIC RIC Block Diagram ### 2.1. Relationship between RIC files in FlexRIC ![](https://i.imgur.com/M4RWlHy.png) ___ #### 2.1.1. asio_ric.h Identical to `asio_agent.h` (see [FlexRIC Agent implementation](https://hackmd.io/69m_bUtkR76kExxteiudfg?view=)). ___ #### 2.1.2. e2ap_ric.h Identical to `e2ap_agent.h`. ___ #### 2.1.3. e2_node.h Contains a structure of E2 node. ```c= typedef struct{ global_e2_node_id_t id; accepted_ran_function_t* accepted; size_t len_acc; } e2_node_t ; ``` Also, contains functions for initialization and freeing E2 node. ```c= void init_e2_node(e2_node_t* n, global_e2_node_id_t const* id, size_t len_acc, accepted_ran_function_t accepted[len_acc]); void free_e2_node(e2_node_t* n); ``` ___ #### 2.1.4. endpoint_ric.h Identical to `endpoint_agent.h`. ___ #### 2.1.5. influx.h #### 2.1.6. redis.h #### 2.1.7. stdout.h #### 2.1.8. notify_nng_listener.h Listeners. They can optionally be associated with certain RIC functions, for example, receiving MAC stats (`MAC_STATS_V0`). They take received data and output it to: * stdout * Influx Database * Redis * NNG (Nanomessages) ```c= void notify_influx_listener(sm_ag_if_rd_t const* data); void notify_redis_listener(sm_ag_if_rd_t const* data); void notify_stdout_listener(sm_ag_if_rd_t const* data); void notify_nng_listener(sm_ag_if_rd_t const* data); ``` Here is an example of association (taken from `test/near_ric.c`): ```c= static void load_default_pub_sub_ric(near_ric_t* ric) { assert(ric != NULL); void* it = assoc_front(&ric->plugin.sm_ds); void* end_it = assoc_end(&ric->plugin.sm_ds); while(it != end_it){ const uint16_t *ran_func_id = assoc_key(&ric->plugin.sm_ds, it); subs_ric_t std_listener = {.name = "stdout listener", .fp = notify_stdout_listener }; register_listeners_for_ran_func_id(ric, ran_func_id, std_listener); subs_ric_t redis_listener = {.name = "redis listener", .fp = notify_redis_listener }; register_listeners_for_ran_func_id(ric, ran_func_id, redis_listener); subs_ric_t influx_listener = {.name = "influx listener", .fp = notify_influx_listener }; register_listeners_for_ran_func_id(ric, ran_func_id, influx_listener); subs_ric_t nng_listener = {.name = "nanomsg listener", .fp = notify_nng_listener }; register_listeners_for_ran_func_id(ric, ran_func_id, nng_listener); it = assoc_next(&ric->plugin.sm_ds, it); } } ``` Here, all three listeners are associated with each RIC function. ___ #### 2.1.9. keep_alive_timer.h ```c= /* * Naive timer that expires every exp_time_ms and calls the function fun(void* data) */ void init_keep_alive_timer(uint32_t exp_time_ms, void (*fun)(void*), void* data); void stop_keep_alive_timer(void); ``` ___ #### 2.1.10. xapp_msgs.h Structures of NNG xApp messages, for example: ```c= typedef enum{ XAPP_MAC_REPORT, XAPP_RLC_REPORT, XAPP_PDCP_REPORT, XAPP_RRC_REPORT, XAPP_SLICE_REPORT, } xapp_report_e; typedef enum{ XAPP_ANS_OK, XAPP_ANS_UNKNOWN_ID, XAPP_ANS_ERROR, XAPP_ANS_NOT_IMPLEMENTED } xapp_request_answer_e; ``` ___ #### 2.1.11. req_reply.h Creates separate threads which wait for NNG messages from xApps. ```c= void init_req_reply_server_ping(req_reply_server_arg_t* arg); void init_req_reply_server_msg(req_reply_server_arg_t* arg); void stop_req_reply_server_ping(void); void stop_req_reply_server_msg(void); ``` ___ #### 2.1.12. string_parser.h Converts MAC, RLC, PDCP, Slice stats to string. ```c= void to_string_mac_ue_stats(mac_ue_stats_impl_t* stats, int64_t tstamp, char* out, size_t out_len); void to_string_rlc_rb(rlc_radio_bearer_stats_t* rlc, int64_t tstamp, char* out, size_t out_len); void to_string_pdcp_rb(pdcp_radio_bearer_stats_t* pdcp, int64_t tstamp, char* out, size_t out_len); void to_string_slice(slice_ind_msg_t const* slice, int64_t tstamp, char* out, size_t out_len); ``` ___ #### 2.1.13 msg_handler_ric.h Similarly to `msg_handler_agent.h`, it defines functions to handle messages from Agent and from xApps. ___ #### 2.1.14. near_ric_api.h API to near-RIC. Provides interface for initializing and stopping RIC, as well as for RIC Services, subscribing and unsubscribing for updates from Agent. ```c= void init_near_ric_api(void /* const char* addr , int port*/ ); void stop_near_ric_api(void); void report_service_near_ric_api(/*global_e2_node_id_t const* id,*/ uint16_t ran_func_id, const char* cmd ); void rm_report_service_near_ric_api(/*global_e2_node_id_t const* id,*/ uint16_t ran_func_id, const char* cmd ); void control_service_near_ric_api(uint16_t sm_id, const char* cmd); void insert_service_near_ric_api(uint16_t sm_id, const char* cmd); void policy_service_near_ric_api(uint16_t sm_id, const char* cmd); void load_sm_near_ric_api(const char* file_path); // Observer pattern. Interface for subscription/publish for xApps typedef struct{ void (*update)(const char* data); } subs_t; void susbscribe_near_ric(/*global_e2_node_id_t const* id,*/ uint16_t sm_id, subs_t subscription); void unsusbscribe_near_ric( /*global_e2_node_id_t const* id,*/ uint16_t sm_id, subs_t subscription); ``` ___ #### 2.1.15. near_ric.h Main source file for Near-RIC related functionality. For example, `near_ric_t` initialization, freeing, generating requests, register listeners: ```c= near_ric_t* init_near_ric(const char* addr); void start_near_ric(near_ric_t* ric); void free_near_ric(near_ric_t* ric); size_t num_conn_e2_nodes(near_ric_t* ric); void report_service_near_ric(near_ric_t* ric, /*global_e2_node_id_t const* id,*/ uint16_t ran_func_id, const char* cmd); void rm_report_service_near_ric(near_ric_t* ric, /*global_e2_node_id_t const* id,*/ uint16_t ran_func_id, const char* cmd); void control_service_near_ric(near_ric_t* ric, /*global_e2_node_id_t const* id,*/ uint16_t ran_func_id, const char* cmd); static void register_listeners_for_ran_func_id(near_ric_t* ric, uint16_t const* ran_func_id, subs_ric_t subs) static ric_control_request_t generate_control_request(near_ric_t* ric, sm_ric_t* sm, sm_ag_if_wr_t* wr ) ``` ___ #### 2.1.16. plugin_ric.h Identical to `plugin_agent.h`.

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