Skip to main content

Hello World

Overview​

The Hello World xApp is a basic xApp designed to verify the xApp's connectivity with NearRT-RIC. It prints out the status of connected E2-Nodes upon receiving an E42 Setup Response. It includes the following stages:

  • Init: initializes xApp based on configuration to set up the E42 connection with NearRT-RIC
  • xApp Logic: prints out the connected E2-Nodes stats
  • Exit: terminates xApp

Sequence Diagram​

Detail​

source code: hw.py

Init - Step 2 to 5​

xApp Logic - Step 6​

Develop your xApp logic to display the status of connected E2-Nodes. For instance, if no E2-Node is connected, display an empty table along with a message stating "No E2-Node connected." Conversely, if one or more E2-Nodes are connected, save their information and present it in a table.

  • Example 
    if not (len(conn) > 0):
        print("No E2-Node connected.")

    e2nodes_col_names = ["idx", "nb_id", "mcc", "mnc", "ran_type"]
    e2nodes_data = []
    for i in range(0, len(conn)):
        # NodeB ID
        nb_id = conn[i].id.nb_id.nb_id
        # PLMN
        mcc = conn[i].id.plmn.mcc
        mnc = conn[i].id.plmn.mnc
        # RAN type
        if conn[i].id.type == 0:
            ran_type = "ngran_eNB"
        elif conn[i].id.type == 2:
            ran_type = "ngran_gNB"
        elif conn[i].id.type == 5:
            ran_type = "ngran_gNB_CU"
        elif conn[i].id.type == 7:
            ran_type = "ngran_gNB_DU"
        else:
            ran_type = "Unknown"
        info = [i,
                nb_id,
                mcc,
                mnc,
                ran_type]
        # print(info)
        e2nodes_data.append(info)
    print(tabulate(e2nodes_data, headers=e2nodes_col_names, tablefmt="grid"))

  • Output
    • Case 1: no E2-Node connected 
      No E2-Node connected.
      +-------+---------+-------+-------+------------+
      | idx   | nb_id   | mcc   | mnc   | ran_type   |
      +=======+=========+=======+=======+============+
      +-------+---------+-------+-------+------------+
    • Case 2: one E2-Nodes connected 
      +-------+---------+-------+-------+------------+
      |   idx |   nb_id |   mcc |   mnc | ran_type   |
      +=======+=========+=======+=======+============+
      |     0 |       1 |   505 |     1 | ngran_gNB  |
      +-------+---------+-------+-------+------------+

Exit - Step 7​