UWB vs Zigbee | Difference between UWB and Zigbee
This page compares UWB vs Zigbee and mentions difference between UWB and Zigbee with respect to various comparison parameters.
What is UWB ?
UWB (Ultra Wide Band) technology uses spectrum larger than 500 MHz. In the year 2002, FCC has approved use of unlicensed spectrum within 3.1 to 10.6 GHz for UWB applications. It uses short duration EM (Electro-Magnetic) pulses for high speed data transfer over wide bandwidth (BW). UWB follows IEEE standard 802.15.4a/z. Due to its wide bandwidth it can be used for high data rate (~27 Mbps) communication. It is also popular due to its lower latency, low power consumption and high immunity to various interferences.
The figure depicts UWB network consisting of UWB anchors installed at various places. These anchors communicate with UWB tags and UWB smartphones, UWB lights and WiFi AP. The WiFi AP or router is interfaced with cloud via gateway. UWB technology is used for target sensor data collection from motion sensor, temperature sensor, light sensor etc. It can be used for precise location and tracking applications.
What is Zigbee ?
Zigbee is preferred over wifi and bluetooth to connect large number of battery powered devices. Zigbee is a short range wireless protocol. It used IEEE 802.15.4 physical layer and 2.4 GHz spectrum as used by WiFi and Bluetooth technologies. It operates at very low data rates ( 20 Kbps to 250 Kbps). Zigbee operates using mesh topology and routes data as per AODV protocol >>. Zigbee enabled device offers range of about 10-20 meters (indoors). Zigbee uses 128 bit AES encryption algorithm for secure communication. Zigbee node requires network join time of about 30 seconds compare to WiFi (~ 3 seconds) and bluetooth (~10 seconds). It supports upto 65000 devices (in theory) and 240 devices (in practice). Zigbee technology uses open source standard managed by zigbee alliance.
Zigbee uses three frequency bands viz. 868 MHz (in Europe), 915 MHz (US, Australia) and 2.4 GHz (other countries of the world). Zigbee uses different channels across these bands viz. channel 0 in 868 MHz, channels 1-10 in 915 MHz and channels 11-26 in 2.4 GHz band. For its operation, zigbee uses only one channel from these total channels.
Zigbee network consists of zigbee coordinator, router and end devices. Zigbee is used in various applications such as home automation, medical data collection, industrial control systems etc. Zigbee technology supports different topologies viz. star, mesh and tree.
Difference between UWB and Zigbee
Following table mentions difference between UWB and Zigbee with respect to various parameters.
| Features | UWB | Zigbee |
|---|---|---|
| Standard | IEEE 802.15.3a, IEEE 802.15.4, IEEE 802.15.4z | IEEE 802.15.4 |
| Frequency | sub GHz (500 MHz), lower band (3.5 to 4.5 GHz) and higher band (6.5 GHz to 10 GHz) | 868/915 MHz, 2.4 GHz |
| Range/Coverage | 10 meters | 10-100 meters |
| Bandwidth | 500 MHz to 7.5 GHz | 0.3/0.6 MHz; 2 MHz |
| Modulation | BPSK, QPSK | BPSK (+ ASK), O-QPSK |
| Number of RF channels | 16 (0 to 15) | 1/10; 16 |
| Nominal transmit power | -41.3 dBm/MHz | -25 dBm to 0 dBm |
| Data Protection | 32 bit CRC | 16 bit CRC |
| Latency | Low, in sub milliseconds range | High |
| Power consumption | High | Medium |
| Maximum Signal rate | 110 Mbps | 20/40 Kbps, 250 Kbps |
| Spreading technique | DS-UWB, MB-OFDM | DSSS |
| Basic cell architecture | Piconet | Star |
| Coexistence mechanism | Adaptive frequency hopping | Dynamic frequency selection |
| Extension of basic cell | Peer to peer | Cluster tree, mesh |
| Maximum number of cell nodes | 8 | > 65000 |
Summary: UWB is used for positioning, low latency and low power data transfer applications. Zigbee is used for smart home based IoT applications requiring thousands of nodes with wider coverage range.