UWB vs WiFi | Difference between UWB and WiFi
This page compares UWB vs WiFi and mentions difference between UWB and WiFi 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 WiFi ?
WiFi (Wireless Fidelity) follows different 802.11 series of WLAN IEEE standards viz. 802.11b, 802.11a, 802.11g, 802.11n, 802.11ac, 802.11ax etc. These standards are developed to support various RF frequencies and data rates. The WiFi technology has been developed to avoid use of wires in LAN (Local Area Network) connections between computing devices. WiFi is easy to setup, offers mobility for internet users and delivers very high data rate speed (~ Gbps range) of connections.
IEEE 802.11 standard defines PHY layer and MAC layer specifications. WLAN network consists of APs (Access Points) or routers and Stations. It follows one of the two architectures viz. infrastructure and ad-hoc. WLAN devices use CSMA/CA protocol to avoid collisions when two or more stations try to send WiFi signals simultaneously.
Difference between UWB and WiFi
Following table mentions difference between UWB and WiFi with respect to various parameters.
| Features | UWB | WiFi |
|---|---|---|
| Standard | IEEE 802.15.4 series (802.15.4a, 802.15.4z) | IEEE 802.11 series (11b, 11a, 11g, 11n (WiFi 4), 11ac (WiFi 5), 11ax (WiFi 6) ) |
| Frequency | Three bands viz. sub GHz (500 MHz), lower band (3.5 to 4.5 GHz) and higher band (6.5 GHz to 10 GHz) | 2.4 GHz, 5 GHz, 7 GHz |
| Accuracy | < 30 cm | < 5 to 15 meters |
| Range/Coverage | < 100 meters | < 150 meters |
| Data Communication | Less, Up to 27 Mbps | More, Up to 1 Gbps |
| Secure ranging | Very secure, Distance Time Bounded Protocol | Can be spoofed using relay attack |
| Scalability (Or density) | > 10s of thousands of tags | 100s to a 1000s tags |
| Infrastructure cost | Lower | Higher |
| Reliability | Strong immunity to multi-path and interference | Very sensitive to multi-path, obstructions and interference |
| Modulation schemes used in PHY layer | BPM, BPSK | BPSK, 16-QAM, 64-QAM, 256-QAM, 1024-QAM and OFDM / OFDMA |
| Indoor positioning technique | AoA (ANGLE OF ARRIVAL), ToF ( time of flight ) | RSSI (received signal strength indication) |
| Bandwidth | 500 MHz | Upto 40 MHz at 2.4 GHz, Upto 160 MHz at 5 GHz |
| Number of RF channels | 16 (across all three bands) | 14 (In 2.4 GHz band), 24 (802.11n) to 27 (802.11a) (In 5 GHz band) , 26 ( In 4.9 GHz band) |
| Data Protection | 32 bit CRC | 8 bit CRC or 16 bit CRC based on wifi standard version |
| Latency to get XYZ | Lower, in sub milliseconds range (typically) | higher, greater than 3 seconds (typically) |
| Power consumption | Low to medium | Medium |
| Battery type required | coin cell | Lithium battery |
Summary: UWB is preferred for lower latency, better energy efficiency and accurate positioning applications. WiFi is preferred for high data rate communication.