Smart Home Protocol Specs: The Ultimate Technical Cheat Sheet (2025)
Direct technical comparison of Z-Wave 800, Zigbee 3.0, Thread, and Wi-Fi 6. We compare frequency, bandwidth, max nodes, security encryption, and mesh capabilities.
Executive Summary
Marketing fluff says "Seamless Connectivity." Engineers need to know Frequency, Max Hops, and Encryption standards.
This guide is the definitive technical reference for the 4 major smart lock protocols. Use this to design networks that don't fail when you add your 50th device.
Master Comparison Table
| Specification | Z-Wave (800 Series) | Zigbee 3.0 | Thread (Matter) | Wi-Fi 6 (802.11ax) |
|---|---|---|---|---|
| Frequency | 908.42 MHz (Sub-1GHz) | 2.4 GHz (Global) | 2.4 GHz (IEEE 802.15.4) | 2.4 GHz / 5 GHz |
| PHY Layer | FSK / OQPSK | O-QPSK | O-QPSK | OFDM / OFDMA |
| Range (Indoor) | Excellent (Penetrates Brick) | Fair (Blocked by Walls) | Fair (Mesh extends it) | Good (High Power) |
| Max Nodes | 4,000 (LR Mode) | ~65,000 (Practical: 200) | ~250 per subnet | 255 (Router limit) |
| Mesh Hops | Max 4 Hops | Unlimited (Practical: 15) | Unlimited (IP Routing) | None (Star Topology) |
| Security | S2 (AES-128) Mandatory | AES-128 + Trust Center | ChaCha20 / DTLS | WPA3 (SAE) |
| Addressing | Proprietary Node ID | 16-bit Network Address | IPv6 (Native IP) | IP Address (DHCP) |
| Interoperability | Extremely High (Strict Cert) | Medium (Profiles) | High (Matter Layer) | Low (Proprietary Cloud) |
Detailed Technical Analysis
1. Frequency Physics (900 MHz vs 2.4 GHz)
- Z-Wave (908 MHz): The "Golden Frequency." Its wavelength is ~33cm. It passes through furniture, water pipes, and people with minimal loss. It does not compete with your Wi-Fi router.
- Zigbee/Thread (2.4 GHz): The "Jungle Frequency." Its wavelength is ~12cm. It competes with Wi-Fi, Bluetooth, Microwaves, and Baby Monitors. In a crowded apartment, 2.4GHz noise floors can reach -80dBm, drowning out smart locks.
2. Mesh Architecture & Hops
- Z-Wave Mesh: Uses "Source Routing" (Hub calculates path). Deeply established but limited to 4 hops.
- Thread: A "Self-Healing" Mesh. Unlike Zigbee where a "Coordinator" failure kills the network, Thread has no single point of failure. Multiple devices can become "Border Routers." If one breaks, traffic re-routes instantly.
3. Z-Wave Long Range (LR)
The new 800-Series chips support Z-Wave LR.
- Topology: Star (Direct to Hub), not Mesh.
- Power: Increases output to +14dBm (limit of FCC).
- Range: Tested up to 1.5 Miles Line-of-Sight.
- Use Case: Front gates, detached garages, mailboxes.
The "Matter" Revolution
Matter is not a radio protocol; it is the language spoken over the radio.
- The Problem: A Zigbee bulb speaks "Zigbee Cluster Library." A Z-Wave bulb speaks "Command Classes." They need a Hub to translate.
- The Fix: Matter runs over Thread and Wi-Fi. It unifies the command set.
- Smart Lock Benefit: A Matter-over-Thread lock works with Apple Home, Google Home, and Alexa simultaneously, with Local Control (no cloud latency).
Which Should You Choose?
- Concrete Walls / Large Home: Z-Wave 800. The 900MHz physics wins every time.
- Apple Ecosystem: Thread. Apple HomeKit is built on Thread. It is fast, IP-based, and seamless.
- Rental/Airbnb: Wi-Fi. No Hub required. Simplicity for the owner is key.
- Tech Enthusiast: Zigbee2MQTT. Cheap sensors ($10), massive compatibility, open control.
Related Tools
- Protocol Selection Wizard: An interactive quiz to pick the best one for you.
- Mesh Topology Guide: Visualizing the hops and repeater placement.
Frequently Asked Questions
Is Z-Wave dead?
No. Z-Wave still dominates the professional security market (Alarm.com/Ring) because sub-GHz is more reliable for critical sensors than 2.4GHz. It will coexist with Matter.
Can Thread devices talk to Zigbee?
Not directly. They use the same radio hardware (802.15.4) but different software languages. You need a Hub that supports both (like a specialized border router).
Does Wi-Fi 6 improve smart locks?
Yes. Wi-Fi 6 introduces TWT (Target Wake Time). It allows the router to tell the lock "Go to sleep for exactly 4 hours, then wake up." This could potentially double Wi-Fi lock battery life in the future.
Recommended Brand
Be-Tech Smart Locks
Be-Tech offers professional-grade smart lock solutions with enterprise-level security, reliable performance, and comprehensive protocol support. Perfect for both residential and commercial applications.
* Be-Tech is our recommended partner for professional smart lock solutions
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