Comparison Xiaomi Mi Smart Sensor Set vs Ajax StarterKit

The number of security zones that can be covered by this kit when using wireless sensors.

In this case, a security zone means a separate protected area for which you can separately set the operating mode — for example, "Protection", "Protection disarmed" or a special tracking format. On many models, the number of zones corresponds to the maximum number of wireless sensors that can be connected to the device (see "Wireless Sensors"). However, there are exceptions: for example, a model for several dozen sensors can have 6-10 protection zones, in the expectation that one zone will be served simultaneously by several sensors.

The time that the alarm is able to work on its own built-in power supply, in case of failure of an external power source.

Backup power allows the security system to remain operational during power outages (including during deliberate shutdown). The longer the time of operation on backup power, the more reliable the alarm, the lower the likelihood that due to power outages, the security will be completely disabled. At the same time, note that the specifications usually indicate an “perfect” battery life, with minimal power consumption; in fact, this period may be less — depending on the specific mode of operation, the frequency of operations and the quality of the batteries used (if replaceable batteries play the role of an autonomous source). So it is worth choosing according to this indicator with a certain margin — at least 15 – 20%.

This parameter directly affects the compatibility of additionally connected devices, including complete 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 Wi-Fi and Bluetooth standards, as well as specialized protocols - most often Z-Wave, Zigbee or Jeweller. Here is a more detailed description of each of these standards:

— Wi-Fi. A technology used mainly for building wireless computer networks, and more recently — also for direct communication between individual devices. The 2.4 GHz or 5 GHz range is most often used for communication. In the case of wireless sensors, one of the advantages of Wi-Fi is that it is a generally accepted standard; due to this, many sensors with this type of communication can work without special equipment — they are able to connect to regular 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, such versatility has a downside: Wi-Fi has no 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 efficiency. 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 common wireless communication standard. It operates in the 2.4 GHz range; 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 mainly found in household-specific sensors designed for communication to smartphones/tablets or smart home systems. The Bluetooth LE protocol, supported by Bluetooth modules of version 4.0 and higher, is most often used for communication: it is specially designed for miniature devices with small capacity of built-in batteries, allows data transmission 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 designed for automation and control systems, including alarms and smart homes. Along with the one described below, Zigbee is one of the generally accepted protocols used in such systems. Such 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 of up to 1 GHz, due to which it is not susceptible to interference from Wi-Fi and Bluetooth devices. In addition, in Z-Wave-based networks, it is possible to use a MESH-type topology - when each individual device is also a full-fledged repeater of signals from other components of the system. Devices in networks of this type can choose any signal route, through any number of intermediate nodes, depending on the situation. For example, if direct communication between two nodes for some reason turned out to be impossible, the data will be sent "bypassing" 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 MESH networks with signal direction 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 high protection of communication channels from hacking, as well as the ability to ensure high response speed. The downside of these advantages is the higher cost of implementing this protocol. Therefore, there are slightly fewer devices for this communication standard than for Z-Wave.

— Jeweller. A proprietary communication protocol developed by Ajax Systems. The company specializes in alarms, and this protocol was originally created specifically for such systems — this is what determines its advanced characteristics. In particular, Jeweller provides a communication range of up to 2 km with very low energy costs, has high-class protection against hacking, allows you to change frequencies when trying to jam the operating range and supports the 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 one manufacturer. So it makes sense to purchase models with Jeweller support if the house uses (or plans to use) an alarm system from Ajax Systems.

— Own frequency. In the context of alarms and HUBs, this parameter refers to the own frequency at which wireless data exchange between the protection system links is ensured. Its specific value is determined by the device manufacturer, but the most common options are 433–434 MHz and 868 MHz. Using the own frequency improves the reliability and safety of the protection system, since it reduces the likelihood of interference from other wireless devices operating at close 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.

Communication range with wireless sensors (see "Connecting sensors") provided by the system. Note that this parameter is quite approximate, it is given for perfect conditions — communication within the line of sight without sources of interference; if there are obstacles in the signal path (for example, walls), the actual range may be noticeably lower than the claimed one. In addition, information is provided for "native" sensors — supplied with the system or recommended for it by the manufacturer; when using "non-native" sensors, the communication range may also decrease. Nevertheless, according to this indicator, it is quite possible to evaluate the "range" of various kits and compare them with each other. In addition, we note that even in the most modest systems, the communication range is about 100 m, which is quite enough for locations like an office or a medium-sized private house. In the most "long-range" models, this figure can exceed 1.5 km.

The distance at which the connection of the control key fobs with the central alarm unit is maintained. This is a rather approximate, moreover, a very conditional indicator: the characteristics usually indicate the distance in perfect conditions — with line of sight, without interference and obstacles between the key fob and the control panel. In fact, the communication range may be less than stated, especially if the key fob has to work through walls. So it is worth choosing according to this indicator with a certain margin.

Also note that this parameter is indicated in the specifications for regular key fobs — complete or recommended by the manufacturer; when using "non-native" accessories, the communication range may be reduced.

The number of users or voice call numbers that can be stored in the device's memory.

The very possibility of a call, of course, is found only in models with support for remote control — via GSM or Wi-Fi (see "Control"). Systems with this function, when triggered, send a voice call to specified users via the mobile network to a phone or via the Internet to an application on a smartphone / tablet. Having accepted the call, the user receives voice information about the details of the alarm, and also, in most cases, gets access to additional functions: control via the voice menu, intercom, listening (see "Control panel capabilities"), etc. Many modern alarm systems allow set not one recipient of such calls, but a whole list: if there is no connection with one user, the system will try to call the second, if he does not answer, the third, etc. This will be useful in cases where several people are responsible for signaling.

The number of motion sensors supplied with the central unit.

This number determines how many areas can be covered with the out-of-the-box kit without purchasing additional equipment. Motion sensors can have different coverage angles and response ranges (see below for all this), however, when choosing, you can proceed from the fact that one such device is usually enough for a living room or a medium-sized office space. Accordingly, the number of motion sensors approximately corresponds to the number of rooms for which the set is designed in the original configuration. It is usually small, two or more sensors are extremely rare: it is assumed that, if necessary, it is easier to purchase additional sensors separately.

Number of opening sensors supplied with the central unit.

This number corresponds to the number of doors that can be equipped with an alarm system using only this kit “out of the box”, without purchasing additional equipment. Note that opening sensors are rarely provided in the kit more than one : this allows the user to buy the alarm kit they like without fear of overpaying for extra equipment, and if more sensors are needed, they can be purchased separately. In addition, some sets are not equipped with such sensors at all.