def callsign_decode(rawcall):
    """
        Decodes the AX25 encoded callsign
    """

    s = ''
    
    for i in range(0, 6):
        ch = chr(ord(rawcall[i]) >> 1)
        
        if ch == ' ':
            break
            
        s += ch
                                    
    ssid = (ord(rawcall[6]) >> 1) & 0x0f
      
    if s.isalnum() == False:
        return ''
        		   
    if ssid > 0:            
        s += "-%d" % (ssid)

    return s