BIM vs Цифровой двойник: ключевые отличия и преимущества в строительстве

Wireless Technologies in Building Automation Systems: What to Choose and Where the Limits Are

Ten years ago, the question "wired or wireless sensor network" didn't even come up — you'd just run the cable, end of story. Today, in a smart building project, this question is decided separately for each subsystem. And there's no universal answer.

This article was prompted by research by M. Zhabborova for a thesis project, supervised by U.T. Aliev, on implementing wireless data exchange technologies in building life-support systems. (Tashkent University of Information Technologies)

What makes the work interesting is that it doesn't try to sell wireless solutions as a replacement for wired ones. Instead, it shows where wireless communication works — and where using it isn't justified at all.

We ran the study's conclusions through Uspace's own field engineering experience. We break down what clients usually find hard to grasp.

Why Switch to Wireless Networks at All

Let's look at three main reasons:

• First: Running cable in an existing building always means hassle. Dirty work, wall chasing, ceiling teardowns, coordination with tenants. For a business center at 90% occupancy, that means direct losses from downtime on leased space.
• Second: Open-plan layouts — facilities are designed flexibly. Partitions move, zones regularly change purpose. Cable can't keep up with that, but a wireless sensor can be installed in five minutes.
• Third: Battery power. Some monitoring points physically have no power source nearby, and running a cable there is inconvenient or impractical.

That said, the study's authors make an important caveat we fully agree with: a wireless subsystem is a supplement to the wired infrastructure, not a full replacement for it. For critical control circuits — ventilation actuators, chiller pumps, fire suppression systems — only wired channels and redundant wired emergency control lines should be used.

Comparing Technologies: Speed, Power Consumption

There are seven main contenders for building automation systems. Each has its own niche, and confusing or mixing them up is a common mistake at the design stage.

• Wi-Fi (IEEE 802.11): the workhorse with high speed: IP cameras, multimedia panels, mobile clients. The downside is power consumption, which makes Wi-Fi practically unsuitable for autonomous battery-powered sensors. But it can be a good solution in places where constant power supply can be arranged.
• Zigbee (IEEE 802.15.4): a standard designed specifically for buildings. Low power consumption (a CR2032 battery-powered sensor lasts around 2 years), mesh topology support with self-healing, a theoretical capacity of 65,000 nodes. In practice — and this matters — we recommend not exceeding 40–50 nodes per gateway. Speed is modest: 20–250 kbit/s, but that's fine for the slow processes in automation.
• Thread: a relative of Zigbee, but with IPv6 support and encryption. Compatible with the Matter standard — an open smart home ecosystem adopted by the Connectivity Standards Alliance in 2022 to enable interoperability between devices from different manufacturers.
• Bluetooth Low Energy and Bluetooth Mesh: the main application area in buildings: contactless access via smartphone, indoor positioning via beacon signal, and lighting control.
• LoRaWAN: the only technology on this list built for kilometers, not meters. Line-of-sight range is 15–20 km, in dense urban development — 1–5 km. Speed is low (0.3–50 kbit/s), used where data only needs to be transmitted very rarely — for example, once a day. Handy for water, heat, and electricity meters.
• Z-Wave: operates in the sub-gigahertz band, less common in office systems because part of the protocol is closed, but it remains the standard for security alarm systems.
• LTE/NB-IoT: licensed LTE band, range up to 10 km. Used where a site has no radio infrastructure and it's easier to connect to a cellular carrier's network.

Where Wireless Communication Hits the Limits of Physics

Three serious limitations that can force a project redesign.

• Signal attenuation in structures. A 20 cm thick reinforced concrete wall eats up 15–25 dB of signal at 2.4 GHz. Metallized glass (low-E, installed specifically for the building's energy efficiency) — up to 30 dB. This creates a funny paradox: the more energy-efficient the facade, the worse the wireless network works inside it.
• Congestion in the 2.4 GHz band. Wi-Fi, Bluetooth, and Zigbee all operate in it simultaneously. Channels interfere with each other, and speed and network quality drop.
• Power consumption. The less frequent the polling, the longer the battery life. For example, switching from a 1-minute polling interval to 10 minutes increases sensor battery life 7–8 times. That means during operation, batteries need replacing not once a year, but once every five years.

Wireless systems are often convenient to use in large open spaces (warehouses, boiler rooms, pump stations). Here, it's economically justified.

Zigbee: Never for Fire Alarm Systems

Wireless systems carry risks of significant delay or connection loss due to how they're built. Signals can be jammed, monitoring nodes is harder, and transmission delays can be substantial.

For transmitting temperature readings once a minute — nobody will notice. For a fire alarm command or gas shutoff in an emergency — that's critically too much.

That's why international standards (NFPA 72, ASHRAE Guideline 36-2021) require wired channels with guaranteed delivery for fire protection and emergency control systems.

This is exactly the design principle Uspace has used for years, and the study confirms it with calculations: critical infrastructure — wired communication; telemetry and slow peripherals, slow processes — can be wireless.