WiFi 7 is coming, but is it really reliable?

There is no fastest, only faster.

WIFI6 has just become popular, and WIFI7 is here.

Following the launch of WIFI6 (802.11ax), the new standard 802.11be (Extremely High Throughput) was proposed. By analogy, the WIFI Alliance will name the 802.11be standard as WIFI7.

What is WiFi7?

You may wonder why we are already researching WIFI 7 when WIFI 6 is not yet popular? There is no need to be confused, because WIFI 7 is still in the standard-setting stage, and it may take five years for it to be commercially popularized. WIFI 7 is faster than WIFI 6 and has very sensitive signal detection. The most likely standard to become Wi-Fi 7 is the IEEE 802.11be standard under development, which is a direct relative of Wi-Fi 6, the 802.11ax standard.

In the WIFI 7 standard, the 6G frequency band will be added to broaden the bandwidth of network transmission. WIFI 7 can work in 2.4G, 5G, and 6G frequency bands at the same time. Combined with CMU-MIMO technology, WIFI 7 can theoretically reach a maximum network transmission speed of 30Gbps, while the maximum network transmission speed of WiFi 6 is only 9.6Gbps.

In 802.11ax, also known as WiFi 6, the standard uses 1024-QAM modulation, while 802.11be (WiFi 7) is expected to continue to upgrade the modulation method and directly use 4096-QAM, which will expand the transmission data capacity and lay the foundation for a maximum rate of 30Gbps.

However, WiFi 7 is not perfect. For example, the 320MHz ultra-high bandwidth of WiFi 7 can only be achieved with the help of the new 6GHz wireless band. This means that 802.11be cannot achieve its maximum speed on the WiFi 6 compatible band; and on the wireless band where 802.11be technology can really reach full speed, it is actually not backward compatible with previous WiFi standards.

And if you want to really enjoy the network bandwidth of up to 30Gbps claimed by the technology, you need a super wireless network card with 16 antennas, and secondly, you need to buy a wireless router with 16 antennas. The reason for such high-specification equipment is that 802.11be doubles the number of concurrent data streams (MIMO) from the maximum of 8 in this generation to a maximum of 16, and secondly, 802.11be adds the "Cooperative Multi-User Multiple Input Multiple Output (CMU-MIMO)" function.

WiFi7 will have a significant impact on the RF front-end market

Information technology is changing with each passing day, which has benefited mankind and made life difficult for workers in the electronics and chip industries. But it is precisely because of this hardship that workers in these industries like us have opportunities.

Different WiFi technologies have different requirements for RF products. The further you move towards WIFI6 and WIFI7, the higher the requirements for the RF front-end and the higher the requirements for the process.

(1) WIFI4, 802.11n:

2.4G routers have entered thousands of households, and the opportunity for the RF front end is 2.4G FEM, mainly due to the demand for high power. Medium and low power have been integrated. Skyworks and Qorvo no longer update products of this standard. Early products use gallium arsenide technology.

(2) WIFI5, 802.11ac:

This standard introduces the 5.8GHz frequency band, enabling 2.4G and 5.8G dual-band routers. The RF front-ends will include 2.4G FEM and 5.8G FEM.

2.4G FEM, in the beginning, was added to every router. Later, the output power of the RF front end integrated in the router platform could reach 19~20dBm, so it was basically no longer needed. Skyworks has provided 2.4G FEM using gallium arsenide and 2.4G FEM using silicon germanium (SiGe) process. Qorvo sticks to gallium arsenide process.

5.8G FEM, 7 years ago, Skyworks first launched the 5.8G FEM with GaAs process, with an output power of 20dBm@EVM-35dB. Later, a 2*2 packaged SiGe 5.8G FEM was made, which was unsuccessful. The cost was good, but the performance was worse. Qovor insisted on making GaAs 5.8G FEM. Later, the MTK platform adopted the DPD function, and the output power of the integrated 5.8G FEM was also increased to 19dBm, and the opportunities for adding 5.8G FEM were reduced.

(3) WIFI6, 802.11ax:

For 2.4G FEM, Skyworks and Qorvo have all turned to the SiGe process, and the performance tests show that it is quite good. GF is still the best SiGe process, and it is also the foundry chosen by foreign manufacturers. The SiGe process has high R&D costs and is difficult to design. There is a shortage of R&D talents familiar with this process in China. The advantage is that the simulation in the design stage is more accurate and the production consistency is high, but the cost is similar to that of GaAs.

The current of the FEM developed by the silicon germanium (SiGe) process is slightly better. Comparing the gallium arsenide WIFI6 FEM developed by Sanwuwei and the latest FEM of SKY, the operating current of Sanwuwei FEM is [email protected]@DVM-43dB, while the operating current of SKY FEM is [email protected]@DVM-43dB, a difference of 15mA.

For 5.8G FEM, Skyworks and Qorvo both use GaAs process. The experience of foreign R&D on these two processes is that both processes can be used, but the SiGe process is always a little bit worse than the GaAs process. As the requirements for design and performance become higher, the SiGe process becomes more and more incapable, and the GaAs process has to be used.

In terms of WIFI6 main chip technology, especially the underlying software protocol, MTK still has a gap with Qualcomm and Broadcom. The gap between domestic chip manufacturers is even greater. It would be great if China could mass-produce WIFI6 main chips in two years.

MTK's advantages are also obvious. Its technology is balanced. It is very good in baseband chips, software protocols, RF transceivers, RF front-end and other technologies, especially in RF front-end technology, where it leads the world.

Therefore, the MTK WIFI6 low-end solution does not need to use 2.4G WIFI6 FEM and 5.8G WIFI6 FEM, and the RF front end is fully integrated to achieve power output. Qualcomm and Broadcom cannot do this, and other domestic manufacturers cannot do it even more.

Of course, with the arrival of WIFI6, the frequency bands of different countries have changed. China remains unchanged and it is estimated that it will not change in the future. However, the United States and Brazil have expanded the WIFI frequency band to 7.2GHz, and Japan may follow suit. Europe has increased the frequency band to 6GHz. Due to the change in frequency band, the WIFI FEM front-end chip also needs to change. The higher the frequency, the wider the bandwidth, and the higher the requirements for design and process. The process choice is still gallium arsenide. At the same time, the difficulty of integrating the RF front end is increasing.

(4) WIFI7, 802.11.be:

For 2.4G FEM, both SiGe and GaAs processes will exist. For 5.8G FEM, I think it can only be GaAs process, as it is more difficult to integrate the RF front end into the main chip, and FEM plug-in will be the mainstream.

The higher the frequency, the wider the bandwidth, and the faster the speed, the more difficult it is to develop the chip. The gallium arsenide process is relatively advantageous, so gallium arsenide will be the mainstream process and future direction of WIFI FEM.

Although MTK is very powerful and continues to challenge the integrated RF front end, the fact is that the market demand for WIFI FEM is not getting smaller, but getting bigger. For the router market, integration will not be the mainstream. As WIFI technology continues to move forward and the market application becomes wider and wider, the requirements for RF front end are getting higher and higher, and there are many opportunities for RF front end FEM.

Is WiFi7 really reliable?

Although from the current description, "WIFI7" is an exciting technology, the question is, is it really "WiFi7"?

Please note that we do not deny that the next-generation WiFi standard will have a bandwidth specification of 30Gbps or even higher, but the "next-generation WiFi standard" and "WiFi7" may not be directly equated.

Why?

Because there is more than one next-generation WiFi standard, and "WiFi7" is just a commercial symbol used by the WiFi Alliance to promote to ordinary consumers. At least for now, there is no conclusion on which future standard will serve as "WiFi7".

Even if WiFi7 comes out, at the price of 11be, I'm afraid few people can afford it.

Back to WIFI6, which is equivalent to 5G, "Wi-Fi 6" has become a must-have label for various mobile phone manufacturers releasing new phones in 2020.

According to statistics, almost all domestic mobile phone manufacturers have released new products equipped with Wi-Fi 6 functions in the past three months. In the field of smart home, Samsung's world's first Wi-Fi 6 TV has been launched, and more devices such as refrigerators and air conditioners are expected to be labeled in the future.

Some people say that 2020 is the first year of commercial use of Wi-Fi 6. This technology, which has long been invisible, has begun to frequently appear on Weibo hot searches. On February 8, Lei Jun emphasized that Xiaomi 10 is the first mobile phone to support 8×8 MU-MIMO, a new feature of Wi-Fi 6 that can greatly speed up transmission speeds.

It is worth mentioning that in order to enjoy the new network speed brought by Wi-Fi 6, the router must also be upgraded together with the terminal equipment. Routers that support Wi-Fi 6 were intensively launched in the second half of 2019, but the price was as high as 2,000 to 3,000 yuan. By the first half of 2020, the price dropped to a reasonable range of 300 to 400 yuan, and the choices became more and more diverse. Consumers want to experience the high network speed of the new Wi-Fi standard, and the cost is very low.

There is still a long way to go before WIFI7 can enter our lives.