Radio communication range

This page explains factors that affect the quality of radio communication and technologies that enable Ajax devices to consistently transmit events and alarms with photo verification over long distances.
If you are a user
of the system, you will better understand the specifics of the operation of devices that ensure your security.
If you are a PRO
working with the system, you will be able to unleash the potential of Ajax radio protocols and avoid mistakes when installing devices.
is the radio protocol that provides two-way communication between an Ajax hub and devices.
is the radio protocol developed for transmission photos from the motion detectors with visual verification of alarms.

Maximum range

Radio communication data is transmitted via radio waves. Under ideal conditions, there are no obstacles or interference in the path of the waves, and they move from the transmitter to the receiver using the shortest path. It is in the open space conditions where the maximum communication range can be obtained. It is a generally accepted benchmark for comparing the capabilities of radio technologies, as well as equipment using radio communications.
Jeweller and Wings radio protocols have maximum communication ranges of 2,000 and 1, 700 meters accordingly.

Factors affecting the radio communication range

Under real-life conditions, radio waves collide with obstacles. Waves pass through certain obstacles without loss and reflect from others, but there are obstacles that absorb radio waves — the properties of the obstacles depend on the material, shape, and thickness. Rain, snow, dust, even very humid air may be insignificant, but they are obstacles, like people. As a rule, when faced with an obstacle, radio signal attenuates, losing some of its power.
The more obstacles the signal meets, the shorter the data transmission range. In addition, when reflected, radio waves change direction.

Effect of obstacle material on a radio signal

Depending on the material, obstacles can reflect radio waves, absorb them, depriving of some of the power, or have no effect on the radio signal. Such materials are called radiotransparent. The higher the signal absorption coefficient and the thicker the obstacle, the stronger the impact on radio transmission.

Low signal absorption coefficient — up to 3 dB

50% power loss, transmission range 30% shorter
  • Dry red brick 90 mm thick
  • Gypsum board 100 mm thick
  • Dry wood 80 mm thick
  • Glass 15 mm thick

Average signal absorption coefficient — 5-20 dB

Power reduces 10 times; transmission range reduces by 60%
  • Brick 250 mm thick
  • Breeze block 200 mm thick
  • Concrete 100 mm thick
  • Masonry 200 mm thick

More than 20 dB. Signal absorption coefficient

Power reduces more than 100 times; transmission range reduces by 70%
  • Concrete 300 mm thick
  • Reinforced concrete 200 mm thick
  • Aluminum and steel beams
  • Large aquarium filled with water

Obstacles reflecting signals

Signal strength decrease to 10%

On our frequencies, the signal will be reflected by an object with a straight surface and a size of at least 30×30 cm.
All surfaces reflect radio signals to some extent. But metals and mirrors do so in a greater degree.
All surfaces reflect radio signals to some extent. But metals and mirrors do so in a greater degree.

Calculating the radio communication range of Ajax devices

No theory — just practical trials with devices from retail distribution. The trials are carried out at a test site with minimum radio noise and favorable weather conditions: a constant exchange of data between the hub and the device is maintained, with the distance between them gradually increasing. As soon as the hub ceases to acknowledge the reception of events, the communication range is recorded. After confirming the value with several tests, the device is assigned the "communication range" characteristic.

This is an industry-standard approach to communication range determination required to compare devices within the same manufacturer's product line and competing solutions from different manufacturers.

Why Ajax devices have different radio communication ranges

On the device side, the data transmission range depends on the transmitter signal strength, antenna parameters, and receiver sensitivity. Jeweller radio protocol ensures two-way communication between devices. Therefore, each device both transmits and receives signals.
Detectors, relays, and other Ajax devices have different hardware components and antennas, different enclosure materials and power consumption — each factor affects the maximum range of data transmission and reception.
When assessing the communication range between two devices, one should focus on the device with a smaller maximum communication range. For example, if Hub has a range of 2,000 meters, and MotionProtect — 1,700 meters, these devices will be able to exchange data at a distance of up to 1,700 meters.
The radio communication range of an Ajax device is indicated on the packaging, in the user manual, and on the product page on the official website.

How the reliability of radio communication in Ajax systems is ensured

Multi-directional antennas

An Ajax hub/range extender has two multi-directional antennas for Jeweller frequencies oriented 90 degrees relative to one another.

Hubs with photo verification support have dedicated antennas for Wings frequencies. They are also oriented at an angle of 90 degrees relative to one another.

Low noise boards

The selection of quality components minimizes the internal noise of the board and devices.

Event delivery confirmation

The communication between an Ajax hub and system devices is two-way. That’s why, when transmitting an event, alarm or photo, a detector knows that the packets have been received by a hub, and a hub is informed about the successful receipt of a command by a detector (for example, to change the operation setting). If for some reason, the data is not delivered to the addressee, the sending is repeated until the receipt confirmation.

Adjustable pings of devices

Ajax allows setting the ping interval of devices by a hub of 12 to 300 seconds. In case of the minimum interval, a hub needs only 36 seconds to determine if the connection has been lost or the device has become faulty. And just 0.15 seconds later, a notification of the problem is received by the security company and users.

Radio frequency hopping

Ajax hubs use radio frequency hopping — automatic frequency change within a band according to a specific pattern. This ensures efficient protection against radio interference and signals interception: messages split into tiny packets are transmitted at different frequencies, and if a packet is not received by the addressee, it is sent on a different frequency when retransmitted. The Ajax system detects jamming of the radio air and notifies the security company and users about it.

Automatic power adjustment of the radio transmitter

It is not advisable to use the maximum power of radio transmitters in system devices on a regular basis — this makes the air noisy and increases energy consumption, accelerating the discharge of batteries. An Ajax hub analyzes the signal strength of the connected devices and adjusts the power of their transmitters taking into account the current radio environment of a facility.

Ajax radio communication range calculator

Calculator is a tool for theoretically calculating the quality of communication between a device and a hub/range extender at a certain distance, number, and nature of obstacles. It does not take into account all factors affecting radio communication and cannot be used to create a facility radio coverage map. Use the Ajax radio communication tests during installation.

Distance between hub and device












Distance m

We recommend using the range extender to expand the Jeweller radio communication coverage

Learn more

We recommend using the range extender to expand the Jeweller and Wings radio communication coverage

Learn more

Taking into account the number and variability of factors, as well as the complexity of assessing their impact on radio communication between devices in real-life conditions at the site, we insist on the need for a radio mapping and radio communication test when choosing the location of Ajax devices.

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