Comparison TP-LINK Archer T2UH vs TP-LINK Archer T4U

The method of connection to a PC (or other electronics) provided in the adapter (see "Device type").

Note that modern adapters can be conditionally divided into external and internal. The first variety uses a classic USB port — usually according to the USB 2.0 or USB 3.2 gen1 standard ; such adapters are useful when Wi-Fi is needed only occasionally, or when installing an internal adapter is difficult or impossible (for example, if the PC case is still under warranty and you do not want to disassemble it). Internal models, in turn, are connected mainly via PCI-E, less often via PCI or M.2. However, in all cases, the internal adapter is a board that is attached to the expansion slot on the PC motherboard; this option is especially handy if you want to add a permanent Wi-Fi connection to a traditional desktop computer.

And here is a more detailed description of each specific option:

— USB 2.0. A version of USB that is considered obsolete: in particular, the data transfer rate in it does not exceed 480 Mbps, and the power supply is low. Nevertheless, this is quite enough for Wi-Fi equipment, such devices are inexpensive, and you can connect them to the ports of a newer version — USB 3.2 gen1 or gen2 (except that adapters are required for USB-C type hardware connectors). Therefor...e, many external adapters are still produced with this particular version of USB.

— USB 3.2 gen 1. The successor to USB 2.0, formerly known as USB 3.0 and USB 3.1 gen1. Delivers faster speeds — up to 4.8Gbps — and more power. However, in Wi-Fi equipment, such features are not often required, so this type of connection is provided mainly in fairly advanced adapters, where a simpler USB 2.0 no longer allows you to realize all the capabilities of the device.

— PCI-E. One of the most common interfaces for connecting internal peripherals. It is widely used in modern motherboards (even small "motherboards" most often have several of these slots), which is why it is also popular among Wi-Fi adapters. At the same time, wireless adapters are most often connected via PCI-E 1x, which allows you to install them in any free slot (both PCI-E 1x and 4x and even 16x). Note that such a connection allows you to use external antennas — a plate with antennas or with inputs for connecting them can be placed on the back panel of the PC case (similar to how, for example, graphics card outputs are placed). The connection speed via PCI-E depends on the version, but nowadays it is usually at least 1 Gbps — this is quite enough for most cases.

— PCI. An interface for connecting expansion cards, which is the predecessor of the PCI-E described above. Nowadays, it is considered obsolete, but it is still found in "motherboards" — based on the installation of components that do not require high speeds and powerful power. Wi-Fi adapters are quite suitable for these criteria, so you can still find models with this type of connection on the market. One of the advantages of such adapters is that they do not take up PCI-E slots that other, more demanding cards might need.

— M.2. Comparatively new interface used primarily for miniature internal components; Wi-Fi adapters with such a connection are also basically miniature modules with an internal antenna. When buying such an adapter, it is worth remembering that the M.2 standard mainly describes the physical type of connector, and the connection can be made using PCI-E or SATA technology. At the same time, Wi-Fi modules use PCI-E, but the M.2 connectors on the motherboard can only support SATA. Therefore, before buying, it's ok to clarify the availability and specific location of M.2 PCI-E ports on the motherboard. Regarding the capabilities of M.2, it is worth noting that it allows you to achieve even higher speeds than the more traditional PCI-E, with a small size of the connector itself.

The maximum speed provided by the device when communicating wirelessly in the 2.4 GHz band.

This range is used in most modern Wi-Fi standards (see above) - as one of the available or even the only one. The theoretical maximum for it is 600 Mbit. In reality, Wi-Fi at a frequency of 2.4 GHz is used by a large number of client devices, from which congestion of data transmission channels emerges. Also, the number of antennas affects the speed performance of the equipment. It is possible to achieve the speed declared in the specification only in an ideal situation. In practice, it can be noticeably smaller (often by several times), especially with an abundance of wireless technology simultaneously connected to the equipment. The maximum speed at 2.4 GHz is specified in the characteristics of specific models to understand the real capabilities of Wi-Fi equipment. As for the numbers, according to the capabilities in the 2.4 GHz band, modern equipment is conditionally divided into models with speeds up to 500 Mbit inclusive and over 500 Mbit.

The maximum speed supported by the device when communicating wirelessly in the 5 GHz band.

This range is used in Wi-Fi 4, Wi-Fi 6 and Wi-Fi 6E as one of the available bands, in Wi-Fi 5 as the only one (see "Wi-Fi Standards"). The maximum speed is specified in the specifications in order to indicate the real capabilities of specific equipment - they can be noticeably more modest than the general capabilities of the standard. Also, in fact, it all depends on the generation of Wi-Fi. For example, devices with Wi-Fi 5 support can theoretically deliver up to 6928 Mbit (using eight antennas), with Wi-Fi 6 support up to 9607 Mbit (using the same eight spatial streams). The maximum possible communication speed is achieved under certain conditions, and not every model of Wi-Fi equipment fully satisfies them. Specific figures are conditionally divided into several groups: the value up to 500 Mbit is rather modest, many devices support speeds in the range of 500 - 1000 Mbit, indicators of 1 - 2 Gbps can be attributed to the average, and the most advanced models in class provide a data exchange rate of over 2 Gbps.

— External. Outdoor antennas tend to be larger than indoor antennas, and they usually have swivel mounts that allow the rod to be placed in the optimal position, regardless of the position of the device itself. All this has a positive effect on signal strength. In addition, there are removable external antennas — if desired, they can be replaced with more powerful ones. The main disadvantage of this option can be called bulkiness.

— Internal. Antennas located inside the case are considered less advanced than external ones. In most cases, they are smaller, and the performance depends on the position of the device (although many manufacturers use technologies to compensate for this effect). At the same time, equipment with internal antennas has a neat appearance without unnecessary protruding parts.

— External / internal. The presence in the device at once of both types of antennas described above (in this case, there may be more than one of those and others). The presence of several antennas improves the quality of communication, but if they are all external, the device may turn out to be too bulky. Therefore, in some models of routers, a compromise is used: part of the antennas is hidden in the case, which has a positive effect on compactness and appearance.

The presence of a removable antenna(or several antennas) in the design of the device.

Only external antennas can be made removable (see "Type of antennas"). This design is especially convenient for storage and transportation: it allows you to remove external equipment, making the device less bulky. In addition, many devices with this feature allow replacement of standard antennas with others (for example, more powerful ones or with a more optimal radiation pattern). Some of these models are even initially sold without antennas — in the expectation that the user will choose them himself, at his discretion; such equipment is not needed for domestic use, but it can be very convenient when selecting high-quality professional equipment. On the other hand, the detachable design reduces the reliability of the antenna mounting, increases the possibility of failures at the connection point, and increases the cost of the device. Therefore, most modern Wi-Fi equipment is still equipped with fixed antennas.

— WPA. An encryption protocol created as a temporary solution to the most critical vulnerabilities of the WEP described below. It uses a more advanced encryption algorithm, as well as the transmission of passwords in encrypted form. However, the reliability of this standard also turned out to be insufficient, so an improved version, WPA2, was developed.

— WEP. Historically, the first encryption protocol used in wireless networks. It uses encryption from 64-bit to 256-bit, the latter option is considered strong in itself, however, the standard's own vulnerabilities allow a specialist to hack such a communication channel without much difficulty. As a result, WEP is completely obsolete, its support is provided mainly for compatibility with the simplest equipment (especially since it is technically easy to provide this support).

— WPA2. The most popular security standard in modern Wi-Fi equipment. At one time, it became an important update to the original WPA: in particular, the AES CCMP algorithm was introduced into WPA2, which is extremely difficult to crack. Over time, however, some vulnerabilities were identified in this protocol, which led to the development of a more advanced WPA3; however, WPA3 is just beginning to be massively implemented, and in most Wi-Fi devices, WPA2 remains the most advanced standard.
It is worth noting two nuances. First, WPA2 is available in two versions — personal and corporate; in this case, we are talking about pers...onal, corporate options are placed in paragraph "802.1x". Secondly, support for this standard is guaranteed to also be compatible with WEP and original WPA.

— WPA3. A fundamental improvement to WPA2, introduced in 2018, addressing weaknesses identified in WPA2 in the 14 years since it went live. This standard introduced four key innovations:

• Improved security for public networks. Unlike its predecessor, WPA3 encrypts the traffic between the gadget and the router / access point, even if the network is public and does not require a password.
• Protection against the KRACK vulnerability, which allowed hacking the WPA2 communication channel at the time the connection was established. The SAE algorithm is responsible for this protection — more advanced than the previously used PSK. In particular, when establishing a connection via SAE, both devices are considered equal (in PSK, the receiver and transmitter were clearly defined) — this does not allow an attacker to “wedge” between devices using KRACK methods.
• Easy Connect feature — simplifies connection to Wi-Fi networks for devices that do not have displays (in particular, smart home components). Each of these devices will have a QR code on the body, and to connect to the network, it will be enough to scan this code using a smartphone / tablet already connected to this network. However this function is not directly related to WPA3, WPA2 is sufficient for its operation; however, mass adoption of Easy Connect should be expected at the same time as WPA3.
• Improved encryption algorithms for sensitive data, suitable even for government agencies and defense enterprises. However, this feature is relevant mainly for the corporate version of WPA3 — and support for this version is indicated as "802.1x" (see below, in this case we are talking mainly about the personal version of this standard).

In many devices, upgrading from WPA2 to WPA3 can be done in software by installing a new firmware version. However, if support for this protocol is important to you, it is best to choose equipment where such support is initially provided. Also note that the presence of WPA3 is almost guaranteed to also be compatible with WPA2.

— 802.1x. In this case, it implies support for corporate security standards — most often the corresponding versions of the WPA2 protocols, in new devices also WPA3. For example, if the specifications indicate "802.1x" in addition to "WPA3", then this means that this model supports both personal and corporate versions of WPA3. As for the differences between similar versions, one of them is the support for a separate authentication server in corporate protocols. In other words, when using this function, data on accounts and access rights are stored separately from Wi-Fi equipment, on a special secure server, and it is this server that in each case checks the data of the connected equipment and decides whether to allow or deny access.