Wi-Fi7 is here, should the access method of smart home appliances be unified?

In recent years, Wi-Fi specifications have been iterating rapidly. The Wi-Fi 6 standard was released in 2019, with the maximum rate increased from 3.5Gbps in Wi-Fi 5 to 9.6Gbps. In 2020, the Wi-Fi 6E standard was announced, adding support for the 6GHz spectrum. The first draft of the Wi-Fi 7 standard was released in 2021, and recently, another manufacturer demonstrated the Wi-Fi 7 technology on site and stated that terminal devices supporting Wi-Fi 7 will be launched in 2023.

According to the information released, Wi-Fi 7 (the corresponding international standard is 802.11be) will support three frequency bands: 2.4 GHz, 5 GHz and 6 GHz. Based on Wi-Fi 6, Wi-Fi 7 will expand the bandwidth from 160 MHz to 320 MHz, and support technologies such as 4096-quadrature amplitude modulation (4096-QAM), multi-resource unit (Multi-RU), multi-link operation, multi-user multiple input and multiple output enhancement (MU-MIMO), and multi-access point coordination (Multi-AP). The maximum speed of Wi-Fi 7 is at least three times that of Wi-Fi 6 (9.6 Gbps), and is expected to reach 46 Gbps.

Wi-Fi is the king of indoor wireless communication performance

Judging from the parameters, Wi-Fi6/Wi-Fi7 has reached the transmission rate ceiling of the current mainstream wireless communication technologies, especially the planned Wi-Fi7, which can not only handle 4K/8K video transmission, but also support augmented reality (AR), virtual reality (VR), online games, etc., which are applications with high requirements for data throughput and latency performance.

Whether it is Bluetooth, Zigbee or LoRa, the speed is at least 2 orders of magnitude lower than Wi-Fi. Although UWB has a higher speed than Bluetooth and Zigbee, it has no chance of winning compared with Wi-Fi6 or Wi-Fi7, and its penetration rate is low. It has not yet been widely used, and it will not be able to impact the market position of Wi-Fi technology in a short period of time. In terms of communication distance and configuration difficulty, Wi-Fi is not inferior to the above technologies.

As of the current time point, Wi-Fi is the performance king of indoor wireless communication technology. Wi-Fi has very prominent advantages in the competition in the smart home appliance wireless connection market.

First, mobile phones and laptops are now equipped with Wi-Fi as standard, and users can use their mobile phones or computers to manage other devices anytime and anywhere. This is the "mass base" of Wi-Fi technology in the smart home appliance market. Wi-Fi has a good "popularization foundation", low user learning cost, simple configuration, and convenient networking. These are advantages that other competing technologies cannot match except Bluetooth.

Secondly, in video devices such as TVs, projectors, AR, and VR, other competing technologies are unlikely to have sufficient speed to meet the wireless transmission requirements for high-quality video data such as 4K images. High-speed transmission applications are the foundation of Wi-Fi technology.

Third, more and more traditional home appliances are equipped with Wi-Fi as standard. Refrigerators, air conditioners, and washing machines without Wi-Fi can hardly be considered smart home appliances. We have entered the wireless network era, so these products support Wi-Fi technology from the genes.

Achieving high-performance Wi-Fi to overcome these issues

With a wide user base and increasingly better performance indicators, Wi-Fi technology has shown a trend of dominating the smart home appliance market. However, higher performance indicators usually mean that end product developers need to deal with greater challenges.

Taking the implementation of the RF part as an example, Wi-Fi 5 supports 256QAM, while Wi-Fi 6 supports 1024QAM. The increase in QAM places higher linearity requirements on the RF part. (EVM) requires the setting to reach -47dB. At this time, an RF front-end module specially optimized for EVM is required to ensure that the final product can pass the certification.

The upgrade from Wi-Fi 5 to Wi-Fi 6 also increases the sensitivity requirements of the receiver, so the noise coefficient of the receiving path must be reduced. In addition, the evolution of Wi-Fi standards has increasingly higher requirements for power consumption, and achieving high performance at the power consumption level is a challenge for RF design. Increased power consumption means increased heat in the RF module, which reduces overall system performance while affecting data throughput, coverage, and anti-interference capabilities.

In addition, more and more devices use Power over Ethernet (PoE). Power over Ethernet has great limitations on the power of the device. The terminal product must maximize the RF output power under PoE power supply and optimize the RF front-end performance, so the power consumption is low.