More fast? #16

Hi! I think this is not a issue, better a question or a doubt.

Exist any method to make more fast? I explain me :

For example for send a message , take at least 5000 ms ( 5 seconds)
I attempt to reduce the delay time, but in some cases get a ERROR.
For another when receive a msg, at least 2~3 seconds to get.

Actually i was using a old SIM800L (2G) with the Pubsubclient library and the time is very low than with the sim7600E.
Is there any option to reduce the time?

Sorry in advanced, excuse me for my english, is a little bad.

  Serial.println("Publishing Message: LED ON");
  mySerial.println("AT+CMQTTTOPIC=0,8"); //AT Command for Setting up the Publish Topic Name
  **delay(1000);**
  mySerial.println(Publish); //Topic Name
  **delay(1000);**
  mySerial.println("AT+CMQTTPAYLOAD=0,1"); //Payload length
  **delay(1000)**;
  mySerial.println("a"); //Payload message
  **delay(1000);**
  mySerial.println("AT+CMQTTPUB=0,1,60"); //Acknowledgment
  **delay(1000);**