get message form tcp server

arduino code:

#include "SIM900.h"
#include "SoftwareSerial.h"
#include "inetGSM.h";

float tempC = 0, dregn = 0;
int numdata, led = 13, state, flag = 0;
InetGSM inet;

void setup() 
{
  pinMode(led, OUTPUT);
 
  Serial.begin(9600);
  Serial.println("GSM Shield ArduiCar");

 
  if (gsm.begin(9600)){
    Serial.println("Software Serial begin at 9600");
    gsm.forceON();
  }  
    
    gsm.SimpleWriteln("AT+CIPMODE=1");
    delay(2000);
    if (inet.attachGPRS("internet.tele2.lt", "", "")){
      Serial.println("APN Settings ok! Starting GPRS Connection!");
      gsm.SimpleWriteln("AT+CIFSR");
      delay(5000);
      gsm.WhileSimpleRead();
      inet.connectTCPServer(5000);
      delay(5000);
      Serial.println("\nTCP Server waiting at port: 5000");
      Serial.println("\n"); }
}

void loop() {
  state = gsm.read();
  if (state == 'o'){
    digitalWrite(led, HIGH);
    Serial.println("ON");
  }else if (state == 'f'){
    digitalWrite(led, LOW); 
    Serial.println("OFF");
  }
}

float temp(){
  delay(500);
  tempC = analogRead(5);
  delay(500);
  tempC = (5.0 * tempC * 100.0) / 1024.0;
  return tempC;
}

float dreg(){
  delay(500);
  dregn = analogRead(4);
  //dregn = dregn / 1023 * 100;
  delay(500);
  return dregn;
}

and PHP

$service_port = '5000';
$address = '90.142.176.220';
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
$result = socket_connect($socket, $address, $service_port);
socket_write($socket, 'o');
echo socket_read($socket,100);