diff --git a/grc/trx/gsm_freq_hopping.xml b/grc/trx/gsm_freq_hopping.xml
new file mode 100644
index 0000000..9e71e53
--- /dev/null
+++ b/grc/trx/gsm_freq_hopping.xml
@@ -0,0 +1,33 @@
+<?xml version="1.0"?>
+<block>
+  <name>freq_hopping</name>
+  <key>gsm_freq_hopping</key>
+  <import>import grgsm</import>
+  <make>grgsm.freq_hopping($hopping_cmd)</make>
+<!--  <callback>set_fn_time_reference($init_fn, $init_time_secs, $init_time_fracs)</callback>-->
+  <param>
+    <name>Initial hopping command</name>
+    <key>hopping_cmd</key>
+    <value>pmt.to_pmt({'cmd': 'start', 'hopping_params': {'hsn': 1, 'maio': 0, 'ma': [1,2,3,4]} })</value>
+    <type>raw</type>
+    <hide>part</hide>
+  </param>
+
+  <sink>
+    <name>hopping_cmd</name>
+    <type>message</type>
+    <optional>1</optional>
+  </sink>
+
+  <sink>
+    <name>bursts_in</name>
+    <type>message</type>
+    <optional>1</optional>
+  </sink>
+
+  <source>
+    <name>bursts_out</name>
+    <type>message</type>
+    <optional>1</optional>
+  </source>
+</block>