Tag: 802.11ac specification

With two new standards in the works, we could be approaching the Gigabit wireless network

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Understanding gigabit Wireless LAN: 802.11ac and 802.11ad

My comments

What is it all about

At the moment, 802.11n on both the 2.4GHz and 5GHz wavebands is the current link standard for the Wi-Fi wireless network. But the IEEE have decided to work on standards for providing increased-bandwidth wireless networks.

The two standards are 802.11ac, which will primarily work on the 2.4Ghz and 5GHz radio bands and be seen as a migration path from the current 802.11n technology; as well as 802.11ad which works on the 60GHz waveband and has a very short range. The latter technology would be considered best for peer-to-peer applications like short-range wireless backhaul.

Both of these systems will use MIMO (Multiple Input Multiple Output) radio technology; a “front-end diversity” system with multiple transceivers which is what the 802.11n network uses. But this technology will work with at least four “front-ends”; known as “4×4” due to four signals coming in and four going out.

Dedicated bandwidth options

One major benefit that I see with these technologies will provide is dedicated-bandwidth wireless networking which each access point compliant to these standards can do. This is brought on through the use of MU-MIMO (Multi-User Multi-Input Multi-Output) Here, it extends “transmit beamforming” technology which provides improved signal quality in an 802.11n network to allow the access point to provide “switched” Wi-Fi with dedicated bandwidth to stations; similar to the way the typical wired Ethernet network works.

It may be an improvement for network setups with many SSIDs per access point like so-called “guest / hotspot” + “private” networks, shared hotspot access points or many university networks; by allowing full bandwidth to each SSID.

The realities

Of course, the actual throughput that a network link will achieve will typically be less than headline link speed due to overheads associated with the link’s transmission requirements. Here, the average real world maximum throughput will be 867Mbps and the figure may be quoted for first-generation equipment or mature-generation equipment.

How it affects my small network

What will be asked of a small network like a home network would be a 5GHz segment that provides the 802.11ac network.

It may provide for dedicated throughput to client devices like laptops or tablet computers. For those networks that run as dual networks like hotspots or guest networks that share the same wireless router as the private network,the dedicated throughput for each wireless-network segment will be a bonus.

Of course, 2.4GHz will still be used as an 802.11n segment for existing devices and there may be a compatibility mode so that existing 802.11n devices can operate on the same segment.

Other issues

If the 802.11ad technology is to be used as a wireless-backhaul for many 802.11ac access points, there will have to be work on a complementary mesh-network technology. It will then provide a level of fault-tolerance in the wireless backhaul as well as a chance for each station to have and pass on full bandwidth networking. This is something that the IEEE standards body are working on with the 802.11s draft standard.

Conclusion.

It therefore shows that when there is a standard in place, there will be a chance to “raise the bar” with the technology that it covers. This will mean that a Wi-Fi wireless network could become close to the goal of a switched Gigabit network.