From the past few weeks, the first batch of 802.11AC wireless products have started to be listed. In essence, 802.11AC is the current smartphone and notebook computer mainstream 802.11n standard enhanced version, simply from the download speed can have a significant increase, or even to the original 802.11n several times the speed.
The working principle of 802.11AC
802.11AC core technology is mainly based on 802.11a, continue to work in the 5.0GHz band to ensure backward compatibility, but the data transmission channel will be greatly expanded, on the basis of the current 20MHz to 40MHz or 80MHz, or even to the 160MHz. Plus about 10% of the actual frequency modulation efficiency improvement, the new standard theoretical transmission speed is expected to reach 1Gbps, is 802.11n 300Mbps three times times more.
In fact, the 802.11AC project had started in the first half of 2008, when it was called "Very High Throughput" (very good throughput), the goal is directly to reach 1Gbps. By the second half of 2008, the project was divided into two parts: 802.11ac, working under 6GHz, for short-range wireless communication, Officially designated as the successor of 802.11N, the other is 802.11AD, working in 60GHz, market positioning and UWB similar, mainly for home entertainment equipment. At that time, however, the 802.11AC standard had not even entered the draft stage. The new draft standard was expected to be available by the end of 2011 and will eventually be completed by November 2012.
The difference between 802.11AC and 802.11n
From the core technology, 802.11A C is built on top of the 802.11a wireless Wi-Fi standard, including the use of 802.11a 5GHz bands. However, in the channel settings, 802.11AC will continue to use the 802.11n MIMO (multiple) technology, for its transmission rate of 1Gbps to lay the foundation.
802.11AC the operating frequency of each channel will be 802.11n 40MHz, up to 80MHz or even 160MHz, plus about 10% of the actual frequency modulation efficiency improvement, the final theoretical transmission speed will be from 802.11n the highest 600Mbps jumped to 1Gbps. Of course, the actual transmission rate may be between 300mbps~400mbps, close to the current 802.11n actual transmission rate of 3 times times (the current 802.11n wireless router actual transmission rate between 75mbps~150mbps), enough on a channel to simultaneously transmit multi-channel compressed video stream.
In addition, the 802.11AC will be backwards compatible with all of the 802.11 full range of existing and upcoming standards and specifications, including the upcoming release of the 802.11s Wireless network architecture, as well as 802.11u and so on. In terms of security, it will fully comply with all the content of the 802.11i security standards, enabling wireless Wi-Fi to meet the needs of enterprise-class users in terms of security.
According to the 802.11A C implementation goal, the future 802.11AC will be able to help enterprises or families to achieve seamless roaming, and in the roaming process can support Wi-Fi products corresponding security, management and diagnostics applications.
Advantages of 802.11AC
Wireless LAN equipment Manufacturers learn a lot from 802.11n. These experiences are clearly merged into 802.11AC. The two key features of 802.11n MIMO (multi-entry) and channel bindings form the basis of 802.11AC enhancements, as well as some of the more complex optional features.
The first good thing about 802.11AC is that it's designed specifically for the 5GHz band. This band provides greater flexibility for the channel bindings of one of the key data rate enhancements. Channel bindings are typically used in current 802.11n devices. Since most 802.11n devices are designed for 2.4Ghz bands, channel binding in this band can cause serious interoperability problems. The 5GHz band is able to provide more channels in a wider space and is far less sensitive to consumer electronics such as baby monitors, wireless surveillance cameras and microwaves.
Additional Protocol enhancements also specifically make it impossible for channel bindings to cause interoperability problems. This includes the ability to assess whether adjacent bands are clear and available for channel binding, and to allow the device to retain a wider bandwidth before data is transferred. This allows the channel bindings to be raised from 40MHz in 802.11n to 802.11AC 80 to 160MHz. Making channel binding less intrusive and allowing wireless devices to be used by default is key to achieving faster data rates in 802.11AC.
A second benefit for 802.11AC is that, despite a significant increase in data rates, power consumption is reduced compared to 802.11n-like capacity. This was a huge victory.
802.11N began to increase the power limits (especially for mobile/portable devices) to the level where most portable devices cannot take advantage of the full advantages of 802.11n. By using more efficient data encoding mechanisms, 802.11AC allows devices to use fewer transmission paths while still achieving higher data rates. It is the extra RF transmission chain that really consumes power.
In addition, considering that one of the main applications of 802.11AC is to release video within the home, the power problem can be further alleviated because many devices will not move like your 52-inch LCD TV. This means that the alternating current is available. Video transmission is generally one-way. This means that a PC or digital video recorder will deliver video. These devices require more power. The television or ipad is mainly for receiving high-bandwidth signals. These devices require less power.
Finally, 802.11AC introduced an optional feature. A transmission device can transmit streaming video data to multiple receiving devices at the same time. At present, 802.11 communication is actually point-to-point communication. If the same video stream needs to be sent to three clients, it needs three times times the bandwidth. Using 802.11AC, the use of bandwidth will be more efficient.
The future of 802.11AC
802.11AC will be getting faster, as we mentioned earlier, the maximum value of 802.11ac can be 7Gbps. Although in real life and applications will not really reach the theoretical maximum, but in the next few years if the download speed is promoted to 2Gbps, you should not be surprised, 256mb/second download speed will become very mainstream.
Now, more and more hardware manufacturers are starting to find out how to really play 802.11ac potential products. Bo Tong (Broadcom), Qualcomm (Qualcomm), MediaTek (MediaTek), Marvell and Intel are all starting to prepare to exert their force on the 802.11AC standard. On the other hand, the IEEE draft specification has gone through several rounds of voting, and Wi-Fi league Greg Ennis says the final IEEE decision is expected in early 2014. So, if you see more and more 802.11ac products coming into your sight from now on in the market, don't doubt that this is the trend of the future.