Vehicle Tracking System Error

We are trying to make a vehicle tracking system using sim808, gps and gsm antenna, arduino uno, but we have a problem. When we run the codes, there is no answer to the phone and this is the screen. The message that appears on the screen is blank. Normally, the incoming number and location should be displayed.

We use this codes:

#include <DFRobot_sim808.h>
#include <SoftwareSerial.h>

#define MESSAGE_LENGTH 160
char message[MESSAGE_LENGTH];
int messageIndex = 0;
char MESSAGE[300];
char lat[12];
char lon[12];
char wspeed[12];

char phone[16];
char datetime[24];

#define PIN_TX    10
#define PIN_RX    11
SoftwareSerial mySerial(PIN_TX,PIN_RX);
DFRobot_SIM808 sim808(&mySerial);//Connect RX,TX,PWR,

void setup()
{
  mySerial.begin(9600);
  Serial.begin(9600);

  //******** Initialize sim808 module *************
  while(!sim808.init())
  {
      Serial.print("Sim808 init error\r\n");
      delay(1000);
  }
  delay(3000);

  if( sim808.attachGPS())
      Serial.println("Open the GPS power success");
  else 
      Serial.println("Open the GPS power failure");
      
  Serial.println("Init Success, please send SMS message to me!");
}

void loop()
{
  //*********** Detecting unread SMS ************************
   messageIndex = sim808.isSMSunread();

   //*********** At least, there is one UNREAD SMS ***********
   if (messageIndex > 0)
   { 
      Serial.print("messageIndex: ");
      Serial.println(messageIndex);
      
      sim808.readSMS(messageIndex, message, MESSAGE_LENGTH, phone, datetime);
                 
      //***********In order not to full SIM Memory, is better to delete it**********
      sim808.deleteSMS(messageIndex);
      Serial.print("From number: ");
      Serial.println(phone);  
      Serial.print("Datetime: ");
      Serial.println(datetime);        
      Serial.print("Recieved Message: ");
      Serial.println(message); 

    while(!sim808.getGPS())
    {
      
    }

   
      Serial.print(sim808.GPSdata.year);
      Serial.print("/");
      Serial.print(sim808.GPSdata.month);
      Serial.print("/");
      Serial.print(sim808.GPSdata.day);
      Serial.print(" ");
      Serial.print(sim808.GPSdata.hour);
      Serial.print(":");
      Serial.print(sim808.GPSdata.minute);
      Serial.print(":");
      Serial.print(sim808.GPSdata.second);
      Serial.print(":");
      Serial.println(sim808.GPSdata.centisecond);
      Serial.print("latitude :");
      Serial.println(sim808.GPSdata.lat);
      Serial.print("longitude :");
      Serial.println(sim808.GPSdata.lon);
      Serial.print("speed_kph :");
      Serial.println(sim808.GPSdata.speed_kph);
      Serial.print("heading :");
      Serial.println(sim808.GPSdata.heading);
      Serial.println();
  
      float la = sim808.GPSdata.lat;
      float lo = sim808.GPSdata.lon;
      float ws = sim808.GPSdata.speed_kph;
  
      dtostrf(la, 6, 2, lat); //put float value of la into char array of lat. 6 = number of digits before decimal sign. 2 = number of digits after the decimal sign.
      dtostrf(lo, 6, 2, lon); //put float value of lo into char array of lon
      dtostrf(ws, 6, 2, wspeed);  //put float value of ws into char array of wspeed
    
      sprintf(MESSAGE, "Latitude : %s\nLongitude : %s\nWind Speed : %s kph\nMy Module Is Working. Mewan Indula Pathirage. Try With This Link.\nhttp://www.latlong.net/Show-Latitude-Longitude.html\nhttp://maps.google.com/maps?q=%s,%s\n", lat, lon, wspeed, lat, lon);
      
  
       Serial.println("Sim808 init success");
       Serial.println("Start to send message ...");
    
       Serial.println(MESSAGE);
       Serial.println(phone);
  
       sim808.sendSMS(phone,MESSAGE);
  
      //************* Turn off the GPS power ************
      sim808.detachGPS();
  
      
   }
}

Please edit your post to add code tags (select, "</>" button in post editor).