Download speeds of LTE/3G/HSPA data connections and connection reliability are heavily dependent on the available signal quality. The signal strength depends on the distance to the base station, your equipment and on the surroundings of your work place. You can compensate for weak elements in this chain by using a suitable additional, external antenna. With an appropriate antenna one can typically improve data throughput by a factor of 2 to 10.
The graph below shows the throughput of the cellular connection while downloading a large file from a website. In this case, a Huawei E160 3G USB stick was used together with the and the external antenna mounted outside on the wall of the house. The speed of the download was 3-6 times higher with external antenna than without, which improves the user experience is significantly.