Why is data transfer speed faster on huawei usb modem?

Question

Mobile Internet

On the tablet, the data transfer rate is very weak. Anywhere catches only 2g network. Although the antenna supports even 4g. On the smartphone, the Alcatel is also weak 2g, although it also catches 3g with other SIM cards. However, on an unlocked usb 4g modem, it already catches a confident 3g signal and the speed is excellent.