title: AT command - USSD
body: <p>I'm using <a href="https://en.wikipedia.org/wiki/Minicom" rel="nofollow noreferrer">Minicom</a> (serial port software for Linux) for interacting with my GSM modem. Actually now I'm trying to use one of my mobile-provider's services with AT commands.</p>
  <p>Here I say, I want to see my balance:</p>
  <pre><code>AT+CUSD=1,*555*87*1234#
  
  OK
  
  +CUSD: 1,&quot;this service will deduct you 5cent from your balance, to continue please enter 1&quot;,15
  </code></pre>
  <p>So, here I sent &quot;1&quot;, but nothing happened and the session got closed.</p>
  <pre><code>AT+CUSD=1,1
  
  OK
  </code></pre>
  <p>Nothing happened, but the session closed.</p>
  <p>With a normal phone, after entering 1, I will get my current balance.</p>