Network Basics: What is the difference between 802.11n vs 802.11ac?

802.11n vs 802.11ac. What is the difference between them? How about the history and future development of Wi-Fi trends? In this article, you will have a deeper understanding of Wi-Fi technology.

Introduction:

Mobile devices, PC, and all Internet equipment is surrounded by Wi-Fi connection. You must be very curious about what kind of technology supports Wi-Fi functions. 802.11 standard is Wi-Fi’s protocol which has developed for a long time from b, a, g generation to n, ac generation for now. In this article, it will explain 802.11n vs 802.11ac. Let’s get the basics.

What is 802.11n and 802.11ac?

802.11n is a wireless transmission standard protocol developed based on 802.11g and 802.11a, with the biggest feature being rate improvement. The theoretical rate can reach up to 600Mbps (currently the mainstream in the industry is 300Mbps). 802.11n can operate in two frequency bands: 2.4GHz and 5GHz.

While 802.11ac is the successor to 802.11n. It provides up to 1Gbps bandwidth for multi-station wireless LAN communication, or at least 500Mbps single connection transmission bandwidth, and operates in a 5GHz frequency band.

Therefore, compared with 802.11n, 802.11ac has higher performance which shows wider RF bandwidth (increased to 160MHz), more MIMO spatial streams (increased to 8), multi-user MIMO, and higher order modulation (up to 256QAM).

What is the difference between 802.11n and 802.11ac?

1. Channel Bonding:

802.11n has adopted the technology of Channel Bonding which can bond two 20 MHZ channels together, while 802.11ac bonds four or eight 20 MHz, up to 160 MHZ in the entire channel.

2. 8-channel Data Stream:

• channel Data Stream adopts MIMO technology, using multi-antenna technology to increase data output. And it doesn’t consume more bandwidth and transmission power. Take road as an example, if channel binding only increases the number of lanes on a certain road, then MIMO technology increases the number of roads, which also greatly improves the carrying capacity of the road, allowing for more traffic flow.

802.11n supports 4 data streams, while 802.11ac can support 8 data streams. However, Due to cost and actual performance reasons, commercial chips with 4-way spatial streams have not been available, and achieving 8-way data streams will be more difficult for commercial use. Currently, commercial chips mainly rely on 3-way spatial streams.

3. 256QAM Modulation Technology:

The AM transmission signal set is generally represented by a constellation diagram, with each constellation point corresponding to a signal. The more constellation points there are, the greater the amount of information transmitted. Common forms include 16QAM, 64QAM, and 256QAM.

The 802.11ac adopts 256QAM, so the amount of data carried by a single carrier can reach 8 bits, while 802.11n adopts 64QAM, and can only reach 6 bits. Take transportation as an example, 802.11n is a car, while 802.11ac is a large truck and the transportation capacity is naturally greater than before.

4. Multi-Mumo Technology:

Multi-Mumo Technology is a great breakthrough, which increases the number of wireless access terminals for a single AP and eases high-density deployment. In 802.11n, MIMO is only allowed to be used by a single user at the same time, while 802.11ac can support multi-user MIMO, which means that a single 802.11ac AP can transmit different data streams to two or more devices.

We can imagine the scene when passing through a toll station on a highway, no matter how many lanes the road is, if the number of checkpoints at the toll station is insufficient or inefficient, it will cause traffic congestion; Similarly, MU-MIMO will be the key technology to improve the efficiency of toll stations.

How about the history and future development of 802.11n and 802.11ac?

802.11 technology starts in 1997 and has developed from b generation to a, g generation, until n, ac generation for now. The main improvements are a focus on channel bandwidth, MIMO, modulation methods, etc. greatly improving output performance from 600Mbps to 6.93Gbps, bringing infinite possibilities for more application scenarios that rely on high-traffic wireless communication.

In the future, 802.11ac will become faster and faster, as we mentioned earlier, the theoretical maximum value of 802.11ac can reach 7Gbps. Although it may not truly reach the theoretical maximum in real usage and applications, in the coming years, if the download speed is increased to 2Gbps, you should not be surprised, as 256mb/s download speed will become very mainstream.

Nowadays, more and more hardware device manufacturers are searching for products that can truly unleash the potential of 802.11ac. Broadcom, Qualcomm, MediaTek, Marvell, and Intel are all preparing to contribute to the 802.11ac standard.  If you start seeing more and more 802.11ac products coming into your sight in the market from now on, don't doubt it, this is the future trend.