802.11ac: Another Wireless Standard to Adopt
The standard offers theoretical speeds ranging from 6.5 Mbps to 866.7 Mbps.
There is always another standard coming. This one focused on high throughput wireless networks. It is the IEEE standard 802.11ac, a member of the 802.11 family. Some are calling 5GWi-Fi others Next Gen Wi-Fi. The new standard brings innovations and issues to the wireless networking world.
So what makes this new standard attractive?
* It can deliver speeds three times greater than 802.11n networks.
* The design reduces the number of dead spots within its transmission range.
* It can support streaming media very well, enabling HD video and large file backup.
* It delivers more bandwidth to mobile devices.
* It is designed to be backward compatible to 802.11a and 802.11n networks operating in the 5Ghz frequency band.
This standard uses beamforming technology. Beamforming, also called spatial filtering, is a technique for signal processing used in antenna arrays for directional signal transmission/reception. This is an improvement when compared to the common form of omnidirectional transmission and reception used in existing wireless networks. Beamforming is in the 802.11n standard but it was implemented in very few products.
The standard offers 10 combinations of modulation, coding rates and channel sizes from 20 MHz to 160 MHz. This produces theoretical speeds ranging from 6.5Mbps to 866.7Mbps. These speeds do not account for protocol overhead. As with previous wireless technologies, these theoretical rates are under ideal conditions and will probably not be the real throughput rates. It is likely that the delivered speeds will be 30% to 50% the theoretical speed.
Although the standard is still in draft form, there are 12 chipsets on the market from 6 vendors. There are even some wireless routers on the market supporting 802.11ac. These appear to be based on the second draft, not the third draft that is now in progress. What this means to compatibility with draft 3 I could not determine. So far no compatibility problems have surfaced. The final standard will probably be issued in late 2013.
One of the hardware problems is supporting 802.11ac on existing laptop. A USB adapter for the laptop is needed but such a product is yet to be offered. Expect that new laptops will have 802.11ac included in their design. Another product that will be needed are wireless bridges that can connect older wireless networks to 802.11ac networks.
The speeds of 802.11ac will mean that the access points (AP) will have to have 1Gbps connections back to the switches and routers. Another issue is the Power over Ethernet required. It is most likely that each AP will require about 30 watts, the limit that the 802.1at PoE standard delivers. So the enterprise has to buy new switches or power supplies or power injectors. The wireless network staff will need to perform a new site survey before 802.11ac is implemented.
Information about the introduction of 801.11ac products can be found at Network Computing in the article "Reality Check on the 802.11ac Wireless Standard". The current status of the IEEE standard as of July 2012 can be found at the IEEE site, "Status of Project IEEE 802.11ac".