RFZigbee vs WirelessHART: A Detailed Comparison
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This article compares Zigbee and WirelessHART technologies, highlighting their key differences and similarities.
Zigbee
Zigbee is a lightweight wireless networking protocol designed for simple packet data communication. It’s built upon the IEEE 802.15.4 specifications for the physical (PHY) and Medium Access Control (MAC) layers. Zigbee utilizes Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) for channel access.
A Zigbee network consists of three primary device types:
- Zigbee Coordinator: Manages the network.
- Zigbee Router: Extends the network range.
- Zigbee End Devices: Simple devices with limited functionality.
Zigbee operates on several frequency bands, including 868 MHz, 915 MHz, and 2.4 GHz. The 2.4 GHz band is the most popular globally. Depending on the antenna, transmitter output power, and frequency, Zigbee can cover distances ranging from approximately 10 to 100 meters.
Zigbee supports mesh networking, enabling robust and reliable communication. It offers a data rate of approximately 250 Kbps and can accommodate up to 65,000 devices in a single network. The latest version of the standard is Zigbee 3.0.
Zigbee 3.0 enhances interoperability between different application profiles. This allows devices from various application areas to communicate and form a single, unified network. For example, a Zigbee light bulb can seamlessly interact with a Zigbee-enabled healthcare device on the same network.
WirelessHART
WirelessHART is another wireless communication technology, commonly used in industrial automation applications.
Key features of WirelessHART include:
- TDMA/CSMA Based: Employs a combination of Time Division Multiple Access (TDMA) and Carrier Sense Multiple Access (CSMA) for efficient channel access.
- Wireless Mesh Networking: Supports mesh topology for reliable communication.
- Network Components: A WirelessHART network consists of field devices, a gateway, a network manager, a security manager, and handheld devices.
- Frequency Band: Operates in the 2.4 GHz band, utilizing 16 channels with a 5 MHz spacing.
- Security: Supports 128-bit Advanced Encryption Standard (AES) encryption for secure communication.
Zigbee vs. WirelessHART: Key Differences
The following table summarizes the key differences and similarities between Zigbee and WirelessHART:
| Features | Zigbee | WirelessHART |
|---|---|---|
| Topology supported | Star and Mesh | Star and Mesh |
| Frequency Bands | 868/915 MHz, 2.4 GHz | 2.4 GHz |
| Standard | IEEE 802.15.4 | IEEE 802.15.4, HART comm. protocol |
| MAC mechanism | CSMA/CD | TDMA |
| Channel Hopping | Not supported | Supported |
| Ability to cope with large networks | No | Yes |
| Latency and reliability determinism | No | Yes |
| Built-in security features | Yes | Yes |
| Wireless mesh routing | Supported | Supported |
| Data rate | 250 Kbps | 250 Kbps |
| Range | about 100 meters | about 100 meters |
| Power consumption | Low | Medium |
| Cost | Medium | Medium |
