The SIM800L is available in Pakistan. Sim800L is a cheap and portable GSM module breakout board with all the capabilities of the larger SIM900 gsm module and shields.  Smallest SIM800L GPRS GSM Module has a microSIM card core board quad-band TTL serial port. This is a GPRS GSM module based on the SIMCom SIM800L, which is a GSM GRPS Quad-Band module. You can add voice, text, SMS, and data to your project with this module. Sim800L is an ideal solution for M2M applications, suitable for automotive, industrial and PDA, personal tracking, electricity environment detection, wireless POS, smart metering, and other M2M applications, to provide comprehensive GSM / GPRS text messaging, voice and data transmission services.

Here is an image of the product with external antenna

Tutorial:

SPECIFICATION Of SIM800L GSM Module.

1. Quad-band 850/900/1800/1900MHz
2. GPRS mobile station class B
3. Supports Real-Time Clock
4. Supply voltage range 3.4V ~ 4.4V
5. Supports A-GPS
6. Supports 3.0V to 5.0V logic level
7. Micro SIM Card
8. Compact size 23mm x 35mm x 5.6mm
9. Low power consumption, 1mA in sleep mode
10. GPRS multi-slot class12 connectivity: max. 85.6kbps (down-load/up-load)
11. Controlled by AT Command (3GPP TS 27.007, 27.005 and SIMCOM enhanced AT Commands).

DOCUMENTS

1. Datasheet
2. AT Command Manual
3. TCP-IP Application Note
4. IP Application Note
5. SSL Application Note
6. Email Application Note
7. Software library

TUTORIALS

1. http://www.ayomaonline.com/programming/quickstart-sim800-sim800l-with-arduino/
2. http://www.seeedstudio.com/recipe/358-the-ultimate-child-tracker.html

Package Included:

1 x Pre Soldered Headers SIM800L GSM Module Registered With PTA