Navigating the next frontier of Wi-Fi 7 performance

In wireless communications, the advancement of Wi-Fi® 7 opens a new era of ultra-fast networks and reliable connectivity. Like other technological revolutions, they usually come with growing pains. The importance of comprehensive radio frequency (RF), signalling, and throughput testing cannot be overstated. Such testing is not merely procedural, but a critical step to ensure that Wi-Fi 7 can deliver its promised performance not as an individual device but as a network.

BY XIANG LI, INDUSTRY SOLUTION MARKETING ENGINEER AT KEYSIGHT TECHNOLOGIES

Wi-Fi 6 and 6E set new benchmarks for wireless performance, significantly improving network efficiency, capacity, and speed. RF testing ensures the efficient use of spectrum and minimised interference while signalling tests verify the effective communication between devices and access points. Throughput testing, on the other hand, confirms that the theoretical speed improvements translate into real-world benefits for users.

Before the introduction of Wi-Fi 7 standards, Wi-Fi networks were never meant to carry massive numbers of devices. Manufacturers mostly focus on testing under non-signalling conditions, which means engineers can bypass the standard communication protocols and directly access the physical layer of the wireless device for testing. It simplifies the testing process and focuses on the raw performance. However, it ignores the fact that there could be hundreds of other wireless
devices with complex environmental and channel conditions.

Wi-Fi 7 enables a massive number of devices for both industry and household users, such as phones, smart devices, IoTs, industrial IoTs, routers, range extenders and access points, and customer premise equipment (CPE). Wi-Fi 7 networks will offer distinct advantages in crowded settings, such as airports, stadiums, hospitals, and smart factories. Figure 1 and 2 show how complex the future Wi-Fi network will look. Ignoring the standard communication protocols and other network conditions is not a good idea if manufacturers want their Wi-Fi 7 devices to perform consistently and reliably.

Not to mention, the Wi-Fi standard promises enhanced speed and efficiency by introducing advanced features such as 320 MHz channel bandwidth, 4096-QAM, and Multi-Link Operation (MLO). The complexity of these features requires a more systematic testing approach, one that can accurately simulate real-world environments and satisfy Wi-Fi 7 standards. Additionally, CPE is experiencing significant growth in popularity as cell operators are adopting 5G technology fast. This market expansion requires devices to have seamless transitions between Wi-Fi and cellular networks. Therefore, CPE manufacturers and network operators need to work together and run additional tests to ensure their products and networks are compatible with Wi-Fi 7 and 5G technologies.

RF testing with signalling: The foundational step towards excellence
Evaluating RF performance with signalling emulates how a device under test (DUT) operates in real-world conditions. Analysing the transmission (Tx) and reception (Rx) capabilities is essential for ensuring the device performs as end users expect.

In Wi-Fi development, for both access points (AP) and clients, it’s important to start with RF performance assessment and then progress through the protocol layers. Any deficiencies on the RF layer can impact all subsequent tests at higher levels. RF testing enables isolation of the RF layer Tx and Rx operation.

Transmitter power measurements
The transmitted power is a critical parameter that directly influences the performance and compatibility of the device in a wireless network. Capturing the boundaries for the maximum transmitted power output and the power envelope helps to reduce the risk of interference with other devices operating within the same frequency spectrum. This is particularly important in environments where multiple devices share the same band.

To accurately assess the performance related to transmitted power, engineers need to set up the AP or client device to operate at specific power levels. These levels depend on testing objectives, whether for routine evaluation or for diagnosing problems. Typically, tests involve operating the DUT at its highest or lowest power output during the most intense part of a transmission cycle. This approach is designed to push the device to its operational limits, thereby uncovering any potential weaknesses or failure points.