SIM900.h - how to listen to SoftwareSerial?

Official Hardware Retired GSM Shield
1

Hi, I am trying to switch listening between SIM900 and TinyGPS+ but I have no idea what is the name of SoftwareSerial used by SIM900 library.

My GPS is:

SoftwareSerial ss(10, 11);

so I can listen it with

ss.listen();

but I dont know how to listen to SIM900.

Here is my code:

#include <TinyGPS++.h>
#include <SoftwareSerial.h>
#include "SIM900.h"
#include "sms.h"
 
SMSGSM sms;
char latitude[12];
char longitude[12];
char textnav[180];
char number[]="123123123";
char message[180]="123";
char pos;
char *p;
 
static const int RXPin = 7, TXPin = 8;
static const uint32_t GPSBaud = 9600;
 
// The TinyGPS++ object
TinyGPSPlus gps;
 
// The serial connection to the GPS device
SoftwareSerial ss(RXPin, TXPin);
 
void setup()
{
  Serial.begin(115200);
  ss.begin(GPSBaud);
  if (gsm.begin(2400))
   Serial.println("\nstatus=READY");
 else Serial.println("\nstatus=IDLE");
}
 
void loop()
{
 pos=sms.IsSMSPresent(SMS_UNREAD);
 Serial.println((int)pos);
 if((int)pos>0&&(int)pos<=20){
   Serial.print("Incomming message, POS=");
   Serial.println((int)pos);
   message[0]='\0';
   sms.GetSMS((int)pos,number,message,180);
   p=strstr(message,"PASSWORD");  
   
   if(p){
     Serial.println("Success");
 
          while (ss.available() > 0)
    gps.encode(ss.read());
 
  if (gps.location.isUpdated())
  {
        strcpy(textnav, "comgooglemaps://?q=");
        dtostrf(gps.location.lat(), 1, 6, latitude);
        strcat(textnav,latitude);
        strcat(textnav,",");
        dtostrf(gps.location.lng(), 1, 6, longitude);
        strcat(textnav,longitude);
        Serial.println(textnav);
        sms.SendSMS(number, textnav);
        delay(1000);
         
  }
 
   }
   
   }
 
   sms.DeleteSMS((int)pos);
 
 
 
 delay(2000);
}