Comparison Xiaomi Aqara Hub M1S Gen 2 vs Xiaomi Smart Home Hub 2

This parameter directly affects the compatibility of additionally connected devices, including supplied sensors. Such devices must have the same protocol, otherwise normal operation will be impossible. As for specific options, modern alarm kits can use both common standards Wi-Fi and Bluetooth, as well as specialized protocols - most often Z-Wave, Zigbee or Jeweler. Here is a more detailed description of each of these standards:

- Wi-Fi. A technology used primarily for building wireless computer networks, and more recently also for direct communication between individual devices. For communications, the 2.4 GHz or 5 GHz band is most often used. In the case of wireless sensors, one of the advantages of Wi-Fi is that it is a widely accepted standard; thanks to this, many sensors with this type of communication can work without special equipment - they are able to connect to ordinary wireless routers or even individual devices such as laptops and tablets (some models even allow sending notifications via the Internet, through the same router). However, this versatility also has a downside: Wi-Fi does not have additional optimization for working with wireless sensors. As a result, such communication is inferior to specialized protocols in terms of overall reliability, special functionality and energy e...fficiency. So this type of communication is typical mainly for devices designed for simple conditions of use - such as climate temperature/humidity sensors for smart home systems.

— Bluetooth. Another commonly used wireless communication standard. Operates in the 2.4 GHz band; Unlike Wi-Fi, it is used only for direct communication between devices. It is also poorly suited for professional use (in particular, the response delay can reach 2–3 seconds), and therefore is found mainly in household sensors designed for communication to smartphones/tablets or smart home systems. The most commonly used protocol for communication is Bluetooth LE, supported by Bluetooth modules version 4.0 and higher: it is specially designed for miniature devices with small built-in batteries, allows data transfer with very low energy costs and at the same time provides a range of up to 100 m.

- Z-Wave. A wireless communication standard specifically created for automation and control systems, including alarms and smart home. Along with what is described below, Zigbee is one of the generally accepted protocols used in such systems. Such a communication is simple and inexpensive to implement, while being quite functional and practical. It provides for the transmission of the simplest and shortest control commands, which helps save energy, and operates in the range up to 1 GHz, making it not susceptible to interference from Wi-Fi and Bluetooth devices. In addition, in networks based on Z-Wave, it is possible to use a MESH type topology - when each individual device is also a full-fledged repeater of signals from other system components. Devices in networks of this type can choose any route for the signal, through any number of intermediate nodes, depending on the situation. For example, if direct communication between two nodes for some reason turns out to be impossible, the data will be sent “bypass”, through other network devices, and the system will automatically determine the most optimal route. This makes it easy to organize large networks with a large number of devices and a large coverage area.

- Zigbee. Another communication protocol created for automation systems (including smart home), alarms, industrial control, etc. In many ways it is similar to the Z-Wave described above: it allows you to transmit control signals with low energy costs, as well as create networks MESH with signal routing through several nodes and automatic selection of the optimal route taking into account the current situation in the network. The main differences between Zigbee and Z-Wave are the high protection of communication channels from hacking, as well as the ability to provide high response speed. The downside of these advantages is the higher cost of implementing this protocol. Therefore, slightly fewer devices are produced for this communication standard than for Z-Wave.

— Jeweler. A proprietary communication protocol developed by Ajax Systems. The company's specialty is signaling, and this protocol was originally created specifically for such systems - this is the reason for its advanced characteristics. In particular, Jeweler provides a communication range of up to 2 km at very low energy costs, has high-quality hacking protection, allows you to change frequencies when trying to jam the operating range, and supports simultaneous communication of up to 150 devices per gateway. However, the main disadvantage of this protocol is that its use is limited to devices from a single manufacturer. So it makes sense to purchase models with Jeweler support if your home uses (or plans to use) an alarm system from Ajax Systems.

— Natural frequency. In the context of alarms and HUBs, this parameter refers to the natural frequency at which wireless data exchange is ensured between the links of the protection system. Its specific value is determined by the device manufacturer, but the most common options are 433 – 434 MHz and 868 MHz. Using a natural frequency improves the reliability and protection of the protection system because it reduces the likelihood of interference from other wireless devices operating at similar frequencies. When choosing based on this parameter, it is important to consider equipment compatibility, standards and licensing requirements (in order to avoid potential violations of the law).

The number of wireless sensors that can be simultaneously connected to the central unit (if this connection format is supported — see "Connecting sensors"). This number, by definition, is not less than the number of wireless zones (see the relevant paragraph).

Note that even the most modest modern systems support 6 – 8 wireless sensors, in the most advanced models this number can exceed 100. So you have to pay attention to this parameter mainly in cases where you need to organize a very extensive alarm system.

The presence of its own siren in the standard configuration of the set.

The siren provides an audible and, in some models, a light alarm; sometimes this is enough to stop an encroachment on a protected object or to attract the attention of security / law enforcement officers. Such equipment can also be purchased separately (if there is a corresponding output, see "Control panel options"). However, in most cases it is more convenient to buy a system that was originally equipped with a siren: this will allow you not to worry about compatibility, and complete sirens usually give out more than a decent number of decibels (see "Siren volume").

The air temperature range in which the alarm components maintain normal operation.

This parameter is important first of all in cases where the alarm is planned to be used outdoors or in unheated rooms. Particular attention in such cases should be paid to whether the system can work at sub-zero temperatures. If we are talking about room temperatures (plus or minus), then you can’t really look at the claimed temperature range — almost any alarm is suitable for such conditions.