Introduced channel simulator in F1 RFSIM CI test scenario

    - adding a new test case
    - the test case simulate a DL radio channel with noise and runs Iperf test with such channel conditions
    - use CustomCommand class to send commands to a Telnet server
    - switched from netcat’s unsupported -N option (OpenBSD) to --send-only (Ncat 7.94) for compatibility with CI

re-sync CI test in F1 RFSIM

- to be used in the future, for CI of RRCReestablishment in RFSIM
- adding four new test cases (040021, 040022, 040023, 040023) to the RFSIM F1 configuration
- the test cases simulate a disruption of the radio channel, verify UE sync loss and resync
  and restore the original channel conditions
- use CustomCommand class to send commands to a Telnet server

temp xml

ci-scripts/xml_files/container_5g_f1_rfsim.xml

@@ -31,6 +31,7 @@
  000022
  000023
  020021
+ 030020
  030021
  030022
  100021
@@ -74,6 +75,14 @@
                 <ping_packetloss_threshold>5</ping_packetloss_threshold>
         </testCase>
 
+        <testCase id="030020">
+                <class>Custom_Command</class>
+                <desc>Simulate a DL radio channel with noise (3 dB)</desc>
+                <node>localhost</node>
+                <command>echo channelmod modify 0 noise_power_dB 3 | nc --send-only 192.168.71.181 8091</command>
+                <command_fail>yes</command_fail>
+        </testCase>
+
         <testCase id="030021">
                 <class>Iperf</class>
                 <desc>Iperf (DL/5Mbps/UDP)(30 sec)</desc>
@@ -94,6 +103,38 @@
                 <iperf_bitrate_threshold>90</iperf_bitrate_threshold>
         </testCase>
 
+        <testCase id="040021">
+                <class>Custom_Command</class>
+                <desc>Simulate a disruption of DL radio channel (ploss 55)(5 sec)</desc>
+                <node>localhost</node>
+                <command>echo channelmod modify 0 ploss 55 | nc -N 192.168.71.181 8091 &amp;&amp; sleep 5</command>
+                <command_fail>yes</command_fail>
+        </testCase>
+
+        <testCase id="040022">
+                <class>Custom_Command</class>
+                <desc>Get UE sync state (UE ID 0)</desc>
+                <node>localhost</node>
+                <command>echo ciUE sync_state 0 | nc -N 192.168.71.181 8091 | grep -E UE_NOT_SYNC</command>
+                <command_fail>yes</command_fail>
+        </testCase>
+
+        <testCase id="040023">
+                <class>Custom_Command</class>
+                <desc>Restoration of the original DL channel conditions (ploss 0)(5 sec)</desc>
+                <node>localhost</node>
+                <command>echo channelmod modify 0 ploss 0 | nc -N 192.168.71.181 8091 &amp;&amp; sleep 5</command>
+                <command_fail>yes</command_fail>
+        </testCase>
+
+        <testCase id="040024">
+                <class>Custom_Command</class>
+                <desc>Get UE sync state (UE ID 0)</desc>
+                <node>localhost</node>
+                <command>echo ciUE sync_state 0 | nc -N 192.168.71.181 8091 | grep -E UE_CONNECTED &amp;&amp; sleep 10</command>
+                <command_fail>yes</command_fail>
+        </testCase>
+
         <testCase id="100021">
                 <class>UndeployGenObject</class>
                 <desc>Undeploy all OAI 5G stack</desc>