<?xml version="1.0"?>
<block>
  <name>Up/Down-link splitter</name>
  <key>gsm_uplink_downlink_splitter</key>
  <import>import grgsm</import>
  <make>grgsm.uplink_downlink_splitter()</make>
  <sink>
    <name>in</name>
    <type>message</type>
    <optional>1</optional>
  </sink>
  <source>
    <name>downlink</name>
    <type>message</type>
    <optional>1</optional>
  </source>  
  <source>
    <name>uplink</name>
    <type>message</type>
    <optional>1</optional>
  </source>  
</block>