MPUs & MCUs


Smarter IoT starts with Wi-Fi 6 dual band adoption


By Rossella Guiot, central marketing manager – connectivity, Renesas; Ture Nielsen, product marketing manager, Renesas; and Lior Weiss, senior director - connectivity & Wi-Fi, Renesas


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n the rapidly evolving world of the Internet of Things (IoT), the choice of Wi-Fi frequency band is more than a technical detail; it is a strategic decision that directly impacts network performance, reliability, latency, range, and power consumption. With Wi-Fi now operating across the 2.4GHz, 5GHz, and the newly introduced 6GHz bands (via Wi-Fi 6E), understanding the strengths and trade-offs of each is essential for designing robust IoT systems.


The shift from single-band to dual-band connectivity


Many early IoT devices were built around Wi-Fi 4, relying solely on the 2.4GHz band. While this band offers broad coverage and better penetration through walls, it suffers from congestion and interference due to limited channel availability. Today, dual-band support, enabling operation on both 2.4GHz and 5GHz, is a foundational design principle for modern IoT ecosystems.


Dual-band connectivity enables devices to intelligently select the optimal band based on range, bandwidth, and power constraints, ensuring resilient coverage, efficient spectrum utilization, and coexistence across diverse deployment scenarios. By leveraging the complementary strengths of both frequency bands, IoT networks can achieve the balance of reach, reliability, and responsiveness required to sustain large-scale, mission- critical connectivity in the evolving digital landscape.


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To demonstrate the practical advantages of 5GHz, a smart building Wi-Fi environment was simulated. Multiple networks operated simultaneously, revealing stark differences between the two bands:  2.4GHz band: Limited to three primary channels, leading to congestion and interference.


5GHz band: Offers eleven or more 14 April 2026


Spectrum of the environment as measured


Figure 1. Wi-Fi test set-up


A Wi-Fi analyzer application was used to examine the frequency spectrum present in the described environment.


Measurement set-up


Figure 2. Wi-Fi EK-RA6W1 evaluation kit (DUT)


The EK-RA6W1 evaluation kit (DUT) was connected over Wi-Fi to an Android phone configured as a Soft AP, enabling wireless data exchange between the two devices. The tests were conducted in an open office space with multiple active Wi-Fi networks and electronic devices operating in the same frequency bands. The goal was to analyze the device’s performance under real-world conditions.


As depicted in Figure 3, the 2.4GHz spectrum appeared heavily congested due to overlapping networks, which may cause higher latency and degraded performance. In contrast, Figure 4 demonstrates that the 5GHz spectrum was more evenly distributed across channels, reducing interference and improving connectivity.


Throughput


Although both the 2.4GHz and 5GHz bands were tested using the same 20MHz channel bandwidth, the 5GHz band consistently delivered significantly higher throughput. This performance boost is largely attributed to the cleaner, less congested spectrum available in the 5GHz band.  Reduced retransmissions: In the 2.4GHz band, limited channel availability and high device density often lead to interference and packet collisions.


 More available channels: The 5GHz band offers a wider selection of non-overlapping channels.


 Lower interference: With less overlap from other technologies like Bluetooth, Zigbee, and microwave ovens, the 5GHz


channels, significantly reducing interference and enabling higher data rates. This cleaner spectrum translates into tangible user benefits: faster throughput, lower latency, lower power consumption, and a more reliable connection, especially in environments with many connected devices.


Performance testing: throughput, latency, and power consumption A series of tests was conducted in a typical congested environment using an access point connected to the Device Under Test (DUT) placed at a fixed distance. Measurements were taken for both 2.4GHz and 5GHz bands.


Components in Electronics www.cieonline.co.uk Figure 3. Wi-Fi 2.4GHz spectrum


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