In previous articles, we introduced the source of the 802.11ax standard and the new challenges it presents, but when we put it together with the 11ac standard, which is now widespread, we do not necessarily know exactly Identify the specific technical differences between the two, even doubts, 11ac has been able to meet the family needs well, we really need 11ax it? I believe I read the current article, the answer is self-evident.
Also known as High-Efficiency Wireless (HEW), 802.11ax increases the average transmission rate per user in a user-dense environment by more than four times, to provide more subscribers in high-density environments And the steady data flow (average transmission rate), will reduce the network congestion effectively, will promote the wireless speed and coverage range greatly.
In addition, 802.11ax standard in addition to backward compatible with 11a / b / n / ac, but also the train station, airports and other high-density scenes of each user's average transfer rate 4 times.
Although similar to 11ac in terms of data rate and channel width, 802.11ax provides a new modulation and coding combination (MCS 10 and 11) with 1024-QAM. Not only that, but with MU-MIMO and OFDMA techniques, Specified down and up chain multi-user jobs.
The 11ax also offers 4X OFDM FFT, narrower subcarrier spacing (4x density) and 4x symbol time to improve robustness and performance of multipath fading environments and outdoors, as well as traffic and channel access Because of its power management is better, so it can bring more long-term battery life.
Based on the above 'capabilities', what are the intended application requirements for 802.11ax?
The first is mobile data offloading, which will generate 38.1 EBs of Wi-Fi offloading per month by 2020 and continue to surpass the monthly forecast for mobile traffic (30.6 EBs), which equates to a few minutes per minute Move more than 6,000 Blu-ray movies in the network;
Second, having a large number of access points and environments where high-density users have heterogeneous devices should know 'Wi-Fi at the airport' ≠ 'home Wi-Fi';
Third, it is well able to adapt to outdoor and mixed outdoor environment.
In contrast, while the 802.11ac standard achieves a link speed of nearly 866 Mbit / s, a wider channel of 160 MHz and a modulation order of 256-QAM in a single spatial stream, when using 8-space streaming 11ac will achieve the theoretical speed of up to 6.97Gbit / s.
But! Unless you are in a RF laboratory, it will be very hard to achieve a 7Gbit / s high-speed wireless network, so in a real airport terminal whenever you want to connect to a public Wi-Fi or check your mail, It is collapsing.
Another important point has to be got, and we say that 802.11ac runs only in the 5GHz band, 802.11ax but can 'eat' 2.4GHz and 5GHz dual band. However, 11ax also covers a major change that narrows subcarrier spacing to 1/4 of the previous 802.11 standard to preserve the existing channel bandwidth.
Not only that, 802.11ax uses a single user and multi-user mode of operation in the single user serial mode, as long as the wireless STA (wireless base station) to obtain media access, it will be a data transfer and Receive jobs; in multi-user mode, you can synchronize multiple non-AP STA jobs, and the standard will further split the mode into multiple users of the chain and the chain. Here, you may feel more confused, so We made a table to compare more intuitively the differences between 11ac and 11ax:
We talk about the 802.11ax wireless standard today, in fact, there are many technical advantages, and even some uncommon vocabulary we have not even heard of, not to mention the sophisticated technology, on its own can simultaneously run at 2.4G and 5G band has been very lovable.
In fact, Broadcom, Qualcomm, Marvell and other chip makers have already introduced 802.11ax-based chip products, and network equipment vendors such as Asus, Ruijie also introduced the appropriate home and Enterprise-class products, but the terminal can support 11ax has not yet come out, I believe this is only a matter of time under the general trend.
