Effective range
The greatest distance at which the modem's built-in router is capable of providing communication via the Wi-Fi interface (see "Connection").
It should be taken into account that in fact the range strongly depends on a number of factors that are not related to the main specs of the modem: the presence of interference and obstacles in the signal path, the specs of the Wi-Fi module of the connected device, the battery charge in this device or the modem itself, etc. Therefore, the actual range indicators can be noticeably lower than the claimed ones: for example, when working through a wall, they are noticeably reduced. However, this spec quite clearly describes the overall range of the device, and comparisons of different models on it are quite acceptable.
Also note that it does not always make sense to purchase a device with a maximum range — although a long range provides additional convenience, it requires high transmitter power, which significantly increases the size and price of the modem. Therefore, when choosing, it is worth proceeding primarily from the intended scenarios of use. For example, if you need a 3G connection to access the Internet on the road from your tablet, a range of several metres will be enough. But for installation in a large private house, it makes sense to look for a model with increased effective range.
4G (LTE)
The 4G (LTE) mobile connection speed supported by the modem.
All modern LTE equipment is assigned one or another category (
Cat.3,
Cat.4,
Cat.6,
Cat.7,
Cat.9,
Cat.12,
Cat.13,
Cat.16,
Cat.18,
Cat.19,
Cat.20,
Cat.22), on which the transmission speed directly depends. This paragraph specifies both this category and specific speed indicators, moreover, in two parameters — for reception and for transmission. The transmission speed is always much lower, but given the specifics of mobile Internet access, this is usually not critical.
Note that equipment with different speed categories will be quite compatible with each other, however, the throughput will be limited by the capabilities of the slower device. It is also worth saying that this paragraph indicates the theoretical maximum; practical amounts can be noticeably lower (depending on the quality of the network coverage and the features of specific electronics). However, a modem with a higher speed category will perform faster in fact.
