Arduino gsm shield not responding. gsmAccess.begin() doesnt work - arduino

Question

I'm trying to get my arduino GSM shield working with the example "Send SMS" code provided. However, when I upload and compile the program, the serial monitor displays "SMS Messages Sender" and nothing else occurs.
I am using Arduino uno r3 and gsm sim 900. powered gsm with 5V 1.5A. I have connected arduino pins 7&8 to pins 7&8 of gsm. I have connected the gsm to ground too.
When I use SoftwareSerial.h it works. But I wish to use GSM.h library which now isn't working. Any help please
// include the GSM library
#include <GSM.h>
// PIN Number for the SIM
#define PINNUMBER ""
// initialize the library instances
GSM gsmAccess;
GSM_SMS sms;
// Array to hold the number a SMS is retrieved from
char senderNumber[20];
void setup() {
// initialize serial communications and wait for port to open:
Serial.begin(9600);
while (!Serial) {
; // wait for serial port to connect. Needed for native USB port only
}
Serial.println("SMS Messages Receiver");
// connection state
bool notConnected = true;
// Start GSM connection
while (notConnected) {
if (gsmAccess.begin(PINNUMBER) == GSM_READY) {
notConnected = false;
} else {
Serial.println("Not connected");
delay(1000);
}
}
Serial.println("GSM initialized");
Serial.println("Waiting for messages");
}
void loop() {
char c;
// If there are any SMSs available()
if (sms.available()) {
Serial.println("Message received from:");
// Get remote number
sms.remoteNumber(senderNumber, 20);
Serial.println(senderNumber);
// An example of message disposal
// Any messages starting with # should be discarded
if (sms.peek() == '#') {
Serial.println("Discarded SMS");
sms.flush();
}
// Read message bytes and print them
while (c = sms.read()) {
Serial.print(c);
}
Serial.println("\nEND OF MESSAGE");
// Delete message from modem memory
sms.flush();
Serial.println("MESSAGE DELETED");
}
delay(1000);
}
i expected this code to enable me to receive message and i can modify it to store the message in variables

Answer 1

Your problem is probably the wiring.
Your board (Arduino UNO R3) has its UART (the one you intend to use when you define Serial.begin(9600) on pins 0 RX and 1 TX. See here for the schematic and picture below (top right corner with tags TX and RX).
Software emulated serial works because you're defining pins 7 and 8 to be the emulated UART TX and RX signals.