Connected devices, up to
The largest number of devices that can be simultaneously connected to the modem via Wi-Fi (see "Connection").
The presence of this limitation is due to the fact that processing network requests from several devices at once requires a fairly large amount of computing resources, and there are not so many of them in miniature electronics like wireless modems. However, even inexpensive models can support about 5 – 6 devices, which is more than enough for most cases; and in more advanced modems, this number can reach 10.
Memory card slot
The presence
of a slot for memory card in the design of the modem. Memory cards are very popular in modern electronics as removable storage media; in wireless modems, there are two main options for working with them. The first one provides use as an external card reader, for exchanging information between the card and the device to which the modem is connected via USB (see below); Simply put, installing a card turns the modem into a "flash drive" with removable storage. And in models with Wi-Fi (see "Type"), it may also be possible to work as a server that provides access to the contents of the memory card to all wireless devices connected to the modem. As for the types of cards, the most common support for the microSD standard is that they are small enough to be easily combined with compact wireless modem cases. Note that even within the same standard of memory cards there are several varieties, and before buying it's worth to clarify which of them the device is compatible with.
SIM card slot
The presence
of a slot for a SIM card in the design of the modem. The abbreviation SIM stands for Subscriber Identification Module, and this is the main purpose of these cards — binding the device to a specific subscriber account (personal account, mobile number, etc.). Note that in this case, the term SIM refers to both the original cards of this standard used in GSM networks, and USIM used in 3G W-CDMA networks (with all relevant add-ons, see "Transmission Technologies"). The presence of a SIM slot is mandatory for modems that support the mentioned communication technologies — they practically do not use firmware for binding to the operator's network.
R-UIM card slot
The presence
of a slot for an R-UIM card in the modem design. The purpose of such cards is similar to the SIM cards described above, but they are used in networks based on CDMA (and, accordingly, in modems with EV-DO support, see "Transmission Technologies"). Note that, unlike devices for GSM and UMTS networks, for CDMA modems a slot for this type of card is not a mandatory element of equipment — many such devices are tied to the network by changing the firmware, which is why operators of such communication may not use R-UIM at all. Therefore, although in general the use of cards is simpler and more convenient for the user than flashing, however, the choice of the presence or absence of an R-UIM slot depends on the requirements of the network with which the modem is planned to be used.
Display
The presence of a
display in the design of the modem. Even the simplest screens used in modern modems are very versatile and capable of displaying almost any service information about the operation of the device (and sometimes not only purely service information). Due to this, this feature provides much more opportunities to inform the user than various indicators. At the same time, we note that this feature is found only in Wi-Fi modems (see above) designed for stand-alone use. This is due to the fact that in models that are connected to another device via USB, the screen of the external device is used for displaying this information, and it simply does not make sense to equip the modem with its own display.
Battery capacity
The capacity of the battery installed in the modem with the corresponding type of power supply (see below).
The higher the capacity, the longer the battery is able to work without recharging, all other things being equal. However, note that the situation of "other things being equal" is almost not found in modern wireless modems. First, different data transmission technologies (see above) have different power consumption; secondly, even models supporting the same standards can differ in power consumption (and battery life) due to design differences. Therefore, this indicator in most cases is purely reference information, and even very similar models can only be compared approximately. When choosing, it is worth focusing primarily on the claimed specs of the battery life (see below).
Operating time (internet browsing)
The maximum operating time of the modem with battery power (see "Power") on a single charge in Internet browsing mode. Such power is typical for Wi-Fi routers, therefore, usually, Internet browsing is supposed to provide access to the World Wide Web for an external Wi-Fi device.
This spec is the main indicator of battery life for any battery-powered modem, because it describes the time of using it for its main purpose without recharging. At the same time, you should know that this indicator is measured under certain "perfect" conditions; the actual operating time depends on a number of factors, including the intensity of browsing, the amount of data transferred, the number of connected devices and the distance to them, the cellular network signal strength, etc. Therefore, in fact, the battery life of the modem may be somewhat lower. Nevertheless, it is quite possible to compare different models with each other according to the operating time stated in the specs.