gr-gsm/grc/receiver/gsm_receiver.xml

<?xml version="1.0"?>
<block>
  <name>GSM Receiver</name>
  <key>gsm_receiver</key>
  <import>import gsm</import>
  <make>gsm.receiver($osr, $arfcn)</make>

  <param>
    <name>Oversampling ratio</name>
    <key>osr</key>
    <value>4</value>
    <type>int</type>
  </param>

  <param>
    <name>ARFCN</name>
    <key>arfcn</key>
    <value>0</value>
    <type>int</type>
  </param>

  <param>
    <name>Num Streams</name>
    <key>num_streams</key>
    <value>1</value>
    <type>int</type>
  </param>
  <check>$num_streams &gt;= 0</check>
  
  <sink>
    <name>in</name>
    <type>complex</type>
    <nports>$num_streams</nports>
  </sink>

  <source>
    <name>bursts</name>
    <type>message</type>
    <optional>1</optional>
  </source>
  
  <source>
    <name>measurements</name>
    <type>message</type>
    <optional>1</optional>
  </source>
</block>