2.4 GHz vs 5 GHz WiFi: Advantages and Disadvantages

This page compares the advantages and disadvantages of 2.4 GHz and 5 GHz WiFi.

It covers the pros and cons of each, helping you decide which is best for your needs.

Introduction

LAN (Local Area Network) refers to a wired network connecting computing devices like PCs, laptops, hubs, and switches using Ethernet cables. However, laying Ethernet cables can be difficult or impossible in certain situations.

To overcome this, Wireless Local Area Networks (WLANs), popularly known as WiFi, were developed. WLAN uses ISM frequency bands, specifically 902-928 MHz, 2400-2483.5 MHz, and 5725-5850 MHz.

WiFi follows the IEEE 802.11 series of standards, operating similarly to a traditional LAN but with a wireless interface. IEEE 802.11 defines PHY (layer-1) and MAC (layer-2) specifications to provide various QoS levels, security, data rates, and distances.

Figure-1: Traditional LAN

Figure-2: Wireless LAN

WLAN can be implemented in two ways: ad-hoc mode and infrastructure mode.

Ad-hoc mode is suitable for a small number of mobile users and doesn’t require an Access Point (AP) or router.

Infrastructure mode uses APs (Access Points) or routers. A group of stations associated with an AP is called a Basic Service Set (BSS). Multiple BSSs are connected to each other and to a Distributed System (DS) by APs. This forms the WLAN architecture.

The AP (Access Point), also known as a WiFi router, provides interoperability between wired computing devices and WiFi devices. It’s typically connected to a single broadband internet connection, allowing multiple WiFi devices to share it for high-speed browsing.

Both 2.4 GHz and 5 GHz frequencies are used in various WiFi standards. Let’s explore these frequencies.

The figure below illustrates the frequency spectrum of both 2.4 GHz and 5 GHz. As you can see, 2.4 GHz has fewer cycles in the same time period as 5 GHz. In the electromagnetic spectrum, 5 GHz is considered a higher frequency than 2.4 GHz.

Figure-3: 2.4 GHz vs 5 GHz waveforms

The following table outlines various features of IEEE 802.11 standards, including 11b, 11a, 11g, 11n, 11ac, and 11ax.

Table-1: 802.11 WiFi Standards

2.4 GHz WiFi

Figure-4: 2.4 GHz WiFi Channels

The figure shows the 2.4 GHz channels used in WiFi networks by routers or APs (Access Points) and Stations (STAs) or clients.

Among all channels, channel-1, channel-6, and channel-11 are non-overlapping, separated by 25MHz. The remaining channels overlap, sharing some frequency spectrum.

Key features of 2.4 GHz WiFi:

• Better coverage range

• Universally compatible

• Used in the 802.11b standard

• Lower bandwidth than 5 GHz

• Higher interference due to widespread use. Only three non-overlapping channels (1, 6, and 11) are available.

  2.4 GHz WiFi is commonly used in large hotels needing coverage in numerous rooms and outdoor areas, as well as in pubs and restaurants requiring cheaper WiFi for customers and facing multiple walls.

5 GHz WiFi

Figure-5: 5 GHz WiFi Channels

The figure shows the 5 GHz channels used in WiFi networks.

There are 25 pre-defined channels, starting from 36, 40, 44, 48, and going up to 149, 153, 157, 161, and 165.

UNII-1 Channels are for domestic applications and are the best to use among 5GHz WiFi channels.

These channels are used for various bandwidths (20 MHz, 40 MHz, 80 MHz, 160 MHz) in different WLAN standards.

Key features of 5 GHz WiFi:

• Faster network speed
• Less interference than 2.4 GHz
• More bandwidth options available
• Shorter range than 2.4 GHz

5 GHz WiFi is often found in cafes attracting working professionals, and hotels with meeting rooms and business events.

Benefits or Advantages of 2.4 GHz WiFi

Here are the benefits of a 2.4 GHz WiFi system:

• Better coverage: Offers better coverage distances, approximately 150 feet indoors and 300 feet outdoors.
• Penetration: The 2.4 GHz RF signal easily passes through walls, floors, and solid objects.
• Licensing: It uses the ISM frequency band, which does not require licensing.
• Cost: 2.4 GHz WiFi devices are generally less expensive.

Drawbacks or Disadvantages of 2.4 GHz WiFi

Here are the drawbacks of a 2.4 GHz WiFi system:

• Speed: Supports lower speeds, around 450 Mbps to 600 Mbps.
• Bandwidth: It supports lower bandwidth.
• Interference: Many wireless devices use the 2.4 GHz frequency. With only three non-overlapping channels compared to the 23 used by 5 GHz WiFi, it suffers from more interference.
• Channel count: It supports fewer channels than 5 GHz WiFi.
• Congestion: It is prone to congestion.

Benefits or Advantages of 5 GHz WiFi

Here are the benefits of a 5 GHz WiFi system:

• Speed: Offers fast speeds, approximately 1300 Mbps (~1.3 Gbps).
• Bandwidth: It supports higher bandwidth (20 MHz/40 MHz/80 MHz/160 MHz) in different WLAN standards.
• Channel count: It supports more channels than 2.4 GHz WiFi.
• Interference: Suffers from less interference compared to 2.4 GHz WiFi.

Drawbacks or Disadvantages of 5 GHz WiFi

Here are the drawbacks of a 5 GHz WiFi system:

• Coverage: Supports shorter coverage distances, approximately 50 feet indoors and 100 feet outdoors.
• Cost: 5 GHz WiFi devices and routers (i.e., APs) are more expensive.
• Penetration: The 5 GHz RF signal has a shorter wavelength and therefore cannot easily pass through walls, floors, and solid objects.
• Compatibility: The network isn’t used by common wireless devices, as it requires 5 GHz specific WiFi APs or routers.