Terminology » WLAN » WiFi 4 vs WiFi 5: Key Differences Explained

WiFi 4 vs WiFi 5: Key Differences Explained

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This article compares WiFi 4 and WiFi 5, highlighting their differences in max speed, range, and other key parameters.

Introduction to WiFi

WiFi, short for Wireless Fidelity, is also known as WLAN (Wireless Local Area Network) because its operation is similar to a LAN. The technical specifications for WLAN are defined in the IEEE 802.11 series of standards.

A WiFi network consists of two main components:

WiFi Router or AP (Access Point): The central hub of the network.
WiFi Clients or Users: The devices that connect to the network.

The evolution of WiFi includes a series of 802.11 WLAN standards: 802.11b (WiFi 1), 802.11a (WiFi 2), 802.11g (WiFi 3), 802.11n (WiFi 4), 802.11ac (WiFi 5), 802.11ax (WiFi 6), and 802.11be (WiFi 7).

wlan

These different WLAN standards have been developed to improve speed, range, and security. WiFi uses multiple access methods to allow multiple devices to communicate on the same network using a single WiFi router simultaneously, as shown in the figure. These methods include:

CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance)
TDMA (Time Division Multiple Access)

WiFi employs MIMO (Multiple-Input Multiple-Output) technology, using multiple antennas for transmission and reception. MIMO improves throughput and reduces signal interference.

The Wi-Fi Alliance certifies WiFi products for interoperability and compliance with industry standards. WiFi technology is continuously evolving, bringing faster and more reliable wireless connectivity to homes, businesses, and public spaces.

WiFi 4 (802.11n)

The IEEE 802.11n standard is referred to as WiFi 4 and is the successor to IEEE 802.11g (WiFi 3). This standard introduced MIMO and Beamforming features. It also supports legacy WiFi versions.

Here are the key features of the WiFi 4 standard:

Operating Frequency Bands: 2.4 GHz and 5 GHz
Modulation Schemes: BPSK, QPSK, 16QAM, and 64QAM (Highest)
Subcarrier Spacing: 312.5 KHz
Bandwidth: 20 MHz, 40 MHz
MIMO Configurations: Up to 4 x 4
MU-MIMO: Not supported

WiFi 5 (802.11ac)

The IEEE 802.11ac standard is referred to as WiFi 5 and is the successor to IEEE 802.11n (WiFi 4). This standard also supports beamforming and multi-user MIMO features. There are two releases in WiFi 5, referred to as Wave 1 and Wave 2.

Key features of the WiFi 5 standard include:

Operating Frequency Bands: 5 GHz
Modulation Schemes: BPSK, QPSK, 16QAM, 64QAM, and 256 QAM (Highest)
Subcarrier Spacing: 312.5 KHz
Channel Bandwidths: 20 MHz, 40 MHz, 80+80 MHz, 160 MHz
MIMO Configurations: Up to 8 x 8
MU-MIMO: Supported in DL/UL

Difference Between WiFi 4 and WiFi 5

The following table compares WiFi 4 and WiFi 5 using various parameters such as max speed and coverage range:

Parameters	WiFi 4	WiFi 5
Max Speed (Maximum Throughput)	600 Mbps (Using 4x4 MIMO, 40 MHz BW and 400 ns GI)	6.93 Gbps (Using 8 spatial streams, MCS9 256QAM, Short Guard Interval (GI) and 160 MHz BW)
Range	70 meters (indoor), 250 meters (outdoor)	80 meters (indoor)
IEEE Standard	802.11n	802.11ac
Operating Frequency	2.4 GHz and 5 GHz	5 GHz only
Bandwidth (BW)	20 MHz, 40 MHz	20 MHz, 40 MHz, 80 MHz, 160 MHz
Data Mapping (PHY Layer)	BPSK, QPSK, 16QAM, 64QAM	BPSK, QPSK, 16QAM, 64QAM and 256 QAM
MIMO User Mode	Single User	Single User (802.11ac Wave 1), Multiple Users (802.11ac Wave 2)
Spatial Streams	4	3 (11ac Wave 1), 3-4 (11ac Wave 2)
Power Consumption	Lower, about 13 Watts	Higher, about 25+ Watts
MIMO Antenna Configuration	4x4	Upto 8x8

Conclusion

From the comparison between WiFi 4 and WiFi 5, we can see that WiFi 5 offers significantly higher maximum speeds (6.93 Gbps) compared to WiFi 4 (600 Mbps), thanks to its advanced PHY parameters and wider channel bandwidths. While WiFi 4 supports both 2.4 GHz and 5 GHz bands, WiFi 5 operates exclusively on the 5 GHz band. As WiFi technology continues to evolve, we can expect even faster speeds and greater ranges in future standards.