GPRS sms unknown 302 error [SOLVED]

Hello all,

I am using the GPRS V2 by seedstudio (seen here) with an arduino Uno. I am using the demo code code shown in the link to send an SMS using an unlocked AT&T go phone SIM card. Everything thing seems to execute fine but after executing the code I receive a 302 Error, meaning the operation (sending the SMS) is not an allowed AT command. What could be the cause of this error?

#include <SoftwareSerial.h>
#include <String.h>

SoftwareSerial gprsSerial(7,8);
 
void setup()
{
  gprsSerial.begin(19200); // GPRS shield baud rate 
  Serial.begin(19200);   
  delay(100);
}
 
void loop()
{
 
  if (Serial.available()) // if there is incoming serial data
   switch(Serial.read()) // read the character
   {
     case 't': // if the character is 't'
       SendTextMessage(); // send the text message
       break;
     case 'd': // if the character is 'd'
       DialVoiceCall(); // dial a number
     case 'p':
       pinTest();
       break;
 
   } 
 
  if (gprsSerial.available()){ // if the shield has something to say
    Serial.write(gprsSerial.read()); // display the output of the shield
  }
}

void pinTest()
{
  gprsSerial.println("AT+CPIN?");
  delay(100);
  gprsSerial.println("AT+COPS?");
}
/*
* Name: SendTextMessage
* Description: Send a text message to a number
*/
void SendTextMessage()
{
  Serial.println("Sending Text...");
  gprsSerial.println("AT+CMEE=1");
  delay(50);
  gprsSerial.println("AT+CMGF=1"); // Set the shield to SMS mode
  delay(100);
  // send sms message, the phone number needs to include the country code
  gprsSerial.println("AT+CMGS = \"+15555550159\"");
  delay(100);
  gprsSerial.println("TEST SUCCESS"); //the content of the message
  delay(100);
  gprsSerial.println((char)26);//the ASCII code of the ctrl+z is 26 (required according to the datasheet)
  //delay(100);
  gprsSerial.println();
  //Serial.println("Text Sent.");
}
 
/*
* Name: DialVoiceCall()
* Description: Can call/dial a phone number
*/
void DialVoiceCall()
{
  gprsSerial.println("ATD+15555550159;");//dial the number, must include country code
  delay(100);
  gprsSerial.println();
}

The issue was the GPRS shield would time out and disconnect to the network because I did not realize it was necessary to battery power the Arduino. xP I assumed the connection to the serial port was all that was needed.