If you are having a problem with your Sun Broadband Wireless signal you can hack it by puting an external antenna.
It will loose your waranty!
Instructions from djinsonic.com
Huawei E220 is built with an internal antenna, that means you can‘t attach an adapter to use third-party antennas commonly employed in areas with bad GSM/HSDPA coverage. Resources on the web stated there is a hidden connector inside the device. Further inspection of the cover proved that there is a hole preparation above this socket. Unfortunately, measurements have shown this jack is not wired to the GSM module. (red circle on the photo)
During my experimentation with a unipole GSM antenna attached to my roof, I accidentally touched the internal antenna‘s metal resonator (red arrow) with the lead wire. The module immediately started communicating with the network, and this was also audible on my stereo nearby that was turned on (loud). The actual wiring used was a cut-off WiFi pigtail that fits in the FME jack on the external anntennas cable.
When I tried to disassemble the device, I broke the „safety pin“ inside, which is in fact a screw holding the two pieces together. This screw can be accessed after removing the top cover (the one that has a bump for the LED indicator). This way one could open the device with enough care and thus leave the warranty untouched.
An important part is the ground connection of the RF cables shield/braid. It should be attached to the metal casing of the GSM module (green arrow), using cellotape is effective. Grounding wire MUST NOT touch the HOT wire attached to the metal strips of the internal antenna. Their shorting can cause damage to the module. Using foil shielding over the insulated wire connection and the cases top part fixes RF leakage.
I assume using directional high-gain antennas with the device can further improve the achieved signal rates.
Please read the full article HERE