Arduino Nano and SIM 808 GSM+GPRS working

I am working on a GPS relatime tracker and I am using SIM808 GPS+GPRS+GSM+Bluetooth sheild which is interfaced to arduino Nano.
I have been trying to setup a TCP connection between my server and my client which is my nano. But whenever I try to establish a connection I am getting reply as TCP closed. I have activated and the GPRS and used AT+CIFSR and other commands like CGACT, CIICR, etc. But no luck in establishing the connection.
I have read that GPS and GPRS do not work at the same time for the above mentioned sheild.
If so, what is my alternative to GPS or GPRS which can work at 9 V and 100ma.
If no, please help me out with the setting up and sending of GPS data from the device to server.