802.11ac – The Fifth Generation of WiFiJune 5, 2013 Leave your thoughts
With the rollout of 802.11ac due sometime this year, we thought a mini overview of the new WiFi standard might be useful for those of you either contemplating an upgrade of your current wireless LAN, or who may have some questions surrounding its features and technologies.
802.11ac is a new WiFi standard operating on the 5Ghz band (thereby avoiding much of the interference from devices operating on 2.4Ghz), and builds on the current 802.11n standard to provide users with the very best in wireless mobility and performance; comparable with that of Gigabit Ethernet networks.
The business networking implications of 802.11ac promise to be significant, as it not only boasts the potential to satisfy higher user densities, but does so whilst maintaining unprecedented levels of QoS (quality of service) and user-experience. This will ultimately allow enterprise environments with large numbers of clients and devices to deliver fast and robust network access like never before.
The increased speed of 802.11ac has been achieved through a number of technologies which allow the provision of far higher data rates across the network. Channel bandwidth (up to 160 MHz), constellation density and the number of spatial streams (up to 8), are all utilised to yield unprecedented levels of performance, which will theoretically enable throughput of up-to 1 Gbit/s, depending on the type of network. In addition, increased modulation and ‘beamforming’ will enable the client to roam further away from the wireless access point than has been previously possible, without any degradation in performance.
As previously mentioned, 802.11ac WiFi technology will also significantly increase the potential capacity of the wireless LAN, allowing higher simultaneous densities of tablets and smartphones onto the network. This is achieved through MU-MIMO (multi-user MIMO), which enables any single AP within the network to support multiple users, sending and receiving signals concurrently to multiple devices.
What does this mean for the user?
The speed of 802.11ac provides enterprise clients with seemingly instantaneous data transfer, consistent quality of service as well as rapid networking, and is robust enough to deal with the demands of high-density, multi –client/multi-device environments. The new standard also further enables the adoption of web 2.0 applications, such as video streaming, through a broader range of devices and provides significant power savings through accelerated log-in and log-off times.
So is it worth the wait?
Faster speeds, wider bandwidths and network future-proofing are all great selling points and certainly worth consideration when 802.11ac clients begin to dominate the enterprise network space. However, this is by no means imminent, and the current 802.11n standard is hardly outdated; albeit slightly slower and more restricted in terms of bandwidth than .11ac, .11n is more than suitable for the majority of today’s enterprise network demands.
What would we suggest?
Taking all of the above into consideration, as 802.11ac features backwards compatibility with 802.11n, some organisations may want to consider installing 802.11ac sooner rather than later; doing so will ensure that they have the technology in place when clients do eventually ‘catch-up’. That said, the choice of hardware on the market is somewhat limited, with Cisco currently offering just one modular device and Aruba’s first .11ac access point unveiled just last month (May 21, bit.ly/1813Rm3).
So, whilst it is worth taking note of the potential of an .11ac wireless LAN, realistic ‘real world’ deployment is still a way off, and immediate action, in most cases, is not necessarily required.
 By Increasing the modulation from the .11n 64-QAM (Quadrature Amplitude Modulation) to 256-QAM, .11ac can achieve a 33% increase in data rates by representing eight bits per symbol rather than the previous maximum of six.
 Beamforming, sometimes referred to as ‘spatial filtering’, is a signal processing technique used to achieve spatial selectivity, improving overall signal transmission or reception.