Hi, you will need an additional CRC9 connector for Huawei E355.
Panel and Yagi Antennas are mono-directional, which maximizes transmission distances.
Commonly used outdoor for direction finding, remote communication.
It is used to point at the nearest cell tower if your entire area is affected by low or poor reception/signal.
This will improve speed, reception, signal and stability.
Omni Antenna is multi-directional with 360 ° radiation.
Being multi-directional, it is also suitable for use as a repeater or for a network base station too.
Commonly used for covering range in near distance.
It is also used to prevent blockages where your area is with good coverage but due to blockage you're facing low signal or reception.

Regards