Wi-Fi spectrum opportunities and threats

The Wi-Fi technology, which started in 1999, has used two spectrum segments since its inception, one is 2.4 GHz and the other is 5 GHz. The former is the IEEE 802.11b standard and the latter is IEEE 802.11a. However, 5GHz is not the global ISM band, so the Wi-Fi Alliance is pushing 2.4GHz.


In the future, home Wi-Fi routers will become more and more powerful. More than half of the existing Wi-Fi routers have dual-band transmissions. Later, they may have three-frequency, four-frequency, and five-frequency...
However, the bandwidth of the 2.4 GHz band is less than 100 MHz, and it is difficult to increase the rate in 2007 and 2009. Therefore, in 2012, the industry began to implement the IEEE 802.11ac standard (initially a draft version), which was mainly based on the 5 GHz band.

Although the 5GHz frequency band is different in configuration and operation, there are hundreds of MHz of spectrum resources available. In addition, the US FCC takes the lead in recycling and opening several frequency bands of 5GHz, which gradually drives other countries to follow suit and improve the global mobility of 5GHz. . The Wi-Fi Alliance has been focusing on 5GHz since 2012. After three years of efforts, more than half of the new Wi-Fi products are shipped to support 5GHz, which is Dual Band.

In 2013, the Wi-Fi Alliance also took over the WiGig Alliance (IEEE 802.11ad standard) and began to develop another frequency band. This is 60 GHz. The 60 GHz and 2.4 GHz are both global ISM bands. However, the 60 GHz frequency is too high and it is difficult to grow. It can transmit and transmit through the wall, but it can transmit at high speed within a short distance, which is suitable for transmitting high-definition audio and video instantly. After adding 60GHz, Wi-Fi became a Tri Band.

In addition, the IEEE organization has also begun to develop the IEEE 802.11ah standard, which is expected to enable Wi-Fi to cut into IoT applications. The 11ah standard adopts 915MHz, lower than 1GHz (Sub-1GHz), and features low-rate, high-coverage, high-transmission transmission. This standard was officially named Wi-Fi HaLow in January 2016, also known as Low-Power Wi-Fi.

If you add 915MHz, Wi-Fi becomes a Quad Band, but 915MHz is not global. Different countries have different applications. Even if some countries have opened, the available bandwidth is not the same as the US.

Talk about this, Wi-Fi seems to be expanding the available spectrum, but in fact, Wi-Fi also has hidden concerns, because the licensed spectrum of LTE technology is gradually insufficient, and also intentionally use 5GHz, but this coverage overlap area will produce Wi-Fi Interference, which caused the Wi-Fi camp and the LTE camp to attack each other with high decibels in 2015. Even if the LTE camp proposed a coexistence technology mechanism, the Wi-Fi camp still believed that the rights were violated and questioned that the coexistence mechanism was unfair and still favored LTE.

Although the 5GHz inherent in Wi-Fi may be eroded by LTE, under the leadership of the US FCC, Wi-Fi has another opportunity, that is, the 3.5GHz band is open, and the 3.5GHz band has been determined to separate authorized and unlicensed bands. The license-free part will give Wi-Fi a chance to develop, and the licensed band is still in the development of LTE.

In summary, Wi-Fi has obtained 915MHz, 2.4GHz, 3.5GHz, 5GHz, 60GHz and other frequency bands, and is gradually ploughing down. The 2.4GHz and 5GHz bands will have the IEEE 802.11ax standard to continue its development in the future, and 60GHz has also been determined to have IEEE 802.11. The ay standard continues its development. The 915MHz is still in its infancy, only the 11ah standard, and there is no corresponding standard for 3.5GHz. I currently estimate that this may be extended in the 11ax standard.

Although Wi-Fi started from 2.4GHz and went to the recent five-way approach, the Wi-Fi Alliance certification seems to be not fast enough. Wi-Fi WiGig certification will be launched in 2014 and 2015, and it has been confirmed to be extended to 2016; Wi-Fi HaLow certification is also determined to be launched in 2018.

The new rate standard is updated every four or five years in the past. The draft version 11n was implemented in 2007 and the draft version 11ac was implemented in 2012. If there is no accident, 2016 will have the opportunity to implement the draft version 11ax, but it may be extended to 2017. year.

In addition to winning more available spectrum, Wi-Fi is also looking for new applications, the aforementioned high-definition instant audio and video transmission, the Internet of Things are, and in 2015 Wi-Fi Alliance also proposed Wi-Fi Aware, expecting Wi-Fi and Bluetooth The same, can provide indoor guidance and positioning function, this standard was proposed in January, and the test certification was opened in June, which is quite fast.

It can be seen that in the future, home Wi-Fi routers will become more and more powerful. More than half of the existing shipments of existing Wi-Fi routers have dual-band, and later, they may have three-frequency, four-frequency, and five-frequency. Electricity, mobile Internet access, also used to share, deliver and play audio and video, also used in Internet of Things applications.

However, by the time the price of Wi-Fi routers may increase, Google's OnHub proposed in August 2015 is already a suggested price of $200, which is much higher than the current general entry of $50 and mid-range $100. Multi-frequency may become a new selling point, but it may also be a reason for the price increase.