What Is a WiFi Spectrum Analyzer and Why Should I Use One?

What Is Wi-Fi Spectrum Analysis?

A WiFi spectrum analysis is the process of measuring the WiFi signal in a certain area and determining its strength. A WiFi spectrum analysis is typically performed to find interference that negatively impacts wireless performance and to eliminate it.

WiFi networks are broadcasted either on the 2.4, 5 GHz, or 6 GHz frequency band. Each of these three frequency bands is divided into multiple channels, which provide a degree of separation of individual networks.

Ideally, no two WiFi networks should run on the same channel, but this is seldom possible in practice. Because of the steep rise of mobile and IoT (Internet of Things), the WiFi frequency spectrum has never been more crowded.

But it’s not just WiFi networks themselves that cause interference and corrupt other WiFi signals, most common electronic devices can create interference and noise as well. That includes microwave ovens, Bluetooth devices, car alarms, CCTV wireless surveillance video cameras, and cordless phones.

Without WiFi spectrum analyzers, locating the exact source of interference would be unreasonably difficult. Fortunately, there are many excellent WiFi spectrum analyzer software solutions available today, and many of them, including NetSpot, are so easy to use that even home users without any IT training can use them to optimize their home networks and say goodbye to slowdowns and connection drops.

Why Do Interference and Noise Affect WiFi (802.11) Networks?

If you’re wondering why interference affects WiFi networks in the first place, then we applaud you for asking the right question. The answer to this otherwise complicated problem is simple: WiFi devices exchange data by radio waves.

Radio waves are a type of electromagnetic radiation that can be emitted by all kinds of devices found in most homes and offices, including smartphones, dumb phones, Bluetooth keyboards and mice, smart meters, and more. In fact, all objects that are warm emit some radio waves, including the Earth itself.

When multiple sources of radio waves are located in the same general area, it’s like when multiple people talk at the same time next to one another and their voices turn to noise. That’s why it’s always a good idea to proactively eliminate as many noise sources as possible using a paid or free WiFi spectrum analyzer.

Which Wi-Fi Spectrum Analyzer Should I Use?

A good WiFi spectrum analyzer should meet certain criteria. It should be able to pick up all signals on the 2.4 GHz, 5 GHz and 6 GHz frequencies and identify all 802.11 networks.

802.11 technology is a set of media access control (MAC) and physical layer (PHY) specifications for implementing wireless local area networks, and there are several different 802.11 protocols used by modern wireless routers and devices today. The following three are by far the most common:

• 802.11g: has a throughput of 54 Mbit/s using the 2.4 GHz band. 802.11g hardware is fully backward compatible with the previous 802.11 specification, 802.11b, 802.11g suffers from the same interference as 802.11b in the already crowded 2.4 GHz range.
• 802.11n: has a throughput of 600 Mbit/s using either the 2.4 or 5 GHz frequency band. 802.11n uses a wireless-networking standard that uses multiple antennas to increase data rates, MIMO (multiple-input and multiple-output). 802.11n doubles the channel width, from 20 MHz to 40 MHz, which results in slightly more than double the data rate over the congested 2.4 GHz band.
• 802.11ac: developed from 2008 through 2013 and published in December 2013 in the IEEE Standards Association, 802.11ac has a multi-station throughput of at least 1 Gbit/s and single-link throughput of at least 500 Mbit/s. It extends the channel with to 160 MHz and adds more MIMO spatial streams (up to eight) and downlink multi-user MIMO (up to four clients).
• 802.11ax: developed from 2014 through 2019 and officially published in February 2021 by the IEEE Standards Association, 802.11ax, also known as WiFi 6, is designed to improve efficiency and performance in high-density environments. It offers a multi-station throughput of up to 9.6 Gbit/s and introduces Orthogonal Frequency-Division Multiple Access (OFDMA) for better spectrum efficiency. It supports up to 160 MHz channel width, includes up to eight MIMO spatial streams, and introduces uplink and downlink multi-user MIMO for enhanced network capacity. Additionally, 802.11ax improves power efficiency with Target Wake Time (TWT), allowing devices to schedule when they wake up to transmit data, reducing power consumption.

Besides latest 802.11 protocols, a good RF spectrum analyzer should also be able to check security settings and understand the four most commonly used Wi-Fi security protocols, which are WEP, WPA, WPA2 and WPA3.

• WEP: ratified in 1997, WEP (Wired Equivalent Privacy) is a security algorithm for IEEE 802.11 wireless networks. In 2004, WEP was declared deprecated by the IEEE due to its weak security. While there are still many networks that WEP, the security they provide couldn’t hold up to any serious hacking attempts.
• WPA: Wi-Fi Protected Access is a security protocol and security certification program developed by the Wi-Fi Alliance as a replacement for WEP. Available since 2003, WPA includes a Message Integrity Check, which is designed to prevent an attacker from altering and resending data packets, replacing the cyclic redundancy check (CRC) that was used by the WEP standard.
• WPA2: while not perfect, WPA2 is the most commonly used WiFi security protocol and security certification program today, and it includes an AES-based encryption mode as well as support for CCMP (Counter Mode Cipher Block Chaining Message Authentication Code Protocol).
• WPA3: while not without its challenges, represents the latest advancement in WiFi security protocols and certification programs. It builds upon the foundation laid by WPA2, introducing enhanced features aimed at improving both security and user experience. WPA3 incorporates stronger encryption methods, including a mandatory use of the more secure AES-GCM (Advanced Encryption Standard with Galois/Counter Mode) for encryption, which offers improved confidentiality and integrity. Additionally, it introduces Simultaneous Authentication of Equals (SAE), which strengthens the handshake process, making it more resilient against offline dictionary attacks. While WPA3 aims to provide a more robust security framework, its adoption is still growing as users transition from WPA2.

NetSpot not only supports the full breadth of 802.11 protocols and WiFi security protocols but it also is able to generate a comprehensive visual survey of WiFi signal, clearly highlighting all areas of signal weakness.

For quick assessments, NetSpot offers the so-called Inspector Mode, which instantly collects every detail about surrounding WiFi networks and presents the gathered information as an interactive table.

NetSpot runs on both macOS and Windows, and you can try it for free to see how this popular wireless spectrum analyzer can help you uncover hidden sources of interference that prevent you from enjoying your internet connection to the fullest.

How to Read a Wi-Fi Spectrum Analysis?

Unlike traditional WiFi spectrum analyzers, which show graphical representations of the RF energy in the monitored spectrum, NetSpot presents interactive tables and charts that clearly display all important information at a glance. Here are some of the things you can learn about available WiFi networks:

• Channel number: Every WiFi network broadcasts on a specific channel, and using the least cluttered non-overlapping channel is essential for achieving the best performance possible.

• Band: The three dominant WiFi bands (2.4 GHz, 5 GHz and 6 GHz) have vastly different characteristics, so it’s important to know which band a network is broadcasted on.

• Signal strength: WiFi signal strength is expressed in dBm, which stands for decibels relative to a milliwatt. Insufficient signal strength can make it impossible to perform more bandwidth-intensive tasks, such as video streaming.

• Noise: Measured in -dBm format (0 to -100), noise indicates the amount of background noise in the analyzed environment. Too much noise can cause interference and negatively affect performance.

In addition to interactive tables and charts, NetSpot can also perform site surveys and present the gathered data in the form of detailed visualizations. These visualizations can show everything from the wireless transmit rate to frequency band coverage.

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