Preparing your WLAN for the new IEEE 802.11ac Wi-Fi standard

IEEE 802.11ac is the next generation of Wi-Fi standard. It improves data rates, network robustness, reliability and bandwidth efficiency. This is essential given increasing mobility and BYOD. It is important for enterprises to understand their application requirements and how and where these devices may be used within a network to leverage the new standard.

As the number of mobile applications has grown, the increased use of smartphones/tablets has resulted in a rise in bandwidth demand. This increased demand is mirrored in the corporate BYOD context because users expect the same experience at work that they have at home. Streaming video, database searches, file transfers and voice over Wi-Fi are applications that are placing ever-increasing demands on a network’s ability to provide consistent bandwidth.

Prohibiting workers from bringing their personal mobile devices to work is not a real option and providing ample wireless bandwidth for enterprise users is a challenge with the current Wi-Fi standards capabilities.

The new standard

IEEE 802.11ac has been defined with the promise of delivering significant increases in bandwidth while improving the overall reliability of a wireless connection. The ultimate goal of this standard is to produce a single-radio design with wireless data rates in excess of 1 Gbps. As with previous extensions to the 802.11 standard, 802.11ac augments the standard with new enhancements while continuing to support all legacy 5 GHz 802.11 devices.

Products based on 802.11ac will meet the challenge of supporting the new wireless bandwidth demands coming into the enterprise.

Technology introduction

802.11ac specifies changes for both the physical and the media access control (MAC) layers of the 802.11 standard, enabling significant improvements in the wireless range and coverage in the 5 GHz band and delivering very high throughput to 802.11ac-capable clients.

As with earlier IEEE 802.11 amendments, 802.11ac specifies improvements over the previous standards and implements new enhancements, yet it maintains backwards compatibility with previous generations of 802.11 in the 5 GHz band.

For the enterprise, 802.11ac represents a better way to deploy Wi-Fi in the 5 GHz band. As 802.11ac clients come into the enterprise, 802.11ac will let vendors build Wi-Fi infrastructures that make more efficient use of the 5 GHz band, creating high-capacity voice systems and pools of multimedia streaming. Enterprise Wi-Fi networks can also use 802.11ac technology to create Virtual Hold Technology (VHT) wireless backhaul links or wireless bridges.

There will be a gradual transition to 802.11ac in the enterprise, and because the 802.11ac technology is implemented at the chip level, hardware replacement will be required. However, 802.11n will not be displaced by 802.11ac. The two standards will coexist in enterprise wireless networks to continue to support legacy devices in the 2.4 GHz band.

Status of IEEE 802.11ac

802.11ac is not yet an approved international standard. Unlike previous generations of 802.11, however, there is no controversy concerning the technical details of the current draft version. As a result, Wi-Fi silicon providers are comfortable developing chipsets based on the 802.11ac draft before it is formally ratified. Providers are already bringing draft 802.11ac chips to market. Final ratification is expected in December 2013.

Enterprise IEEE 802.11ac considerations

In deciding whether or not to deploy 802.11ac, it is important for organisations to understand their wireless application requirements. Initially, there may be only a few devices capable of fully supporting first-generation 802.11ac products. Understanding how and where these devices may be used within a network is critical.

First-generation 802.11ac access point (AP) products will have to be matched with peer 802.11ac clients. This means that a three-stream, 80 MHz channel connection can only be supported between matching AP/client pairs. The maximum benefit from the 802.11ac standard can be ensured wherever peer-to-peer VHT applications can be identified. Multimedia applications are obvious choices, but there may be other applications that can benefit from 802.11ac’s increased bandwidth. Use of machine-to-user, machine-to-machine or real-time security applications are potential candidates for 802.11ac deployments.

With second-generation 802.11ac products, multiuser multiple-input and multiple-output (MIMO) will be supported, expanding the deployment options available to network planners. It will no longer be a requirement that the AP and client have to be matched to the physical link layer. Mobile clients that support 802.11ac will also have improved battery life as a benefit.

Myths debunked

IEEE 802.11ac is for consumers, not enterprise networks: While 802.11ac is initially targeted at consumer applications, it is also important for enterprises. High-performance multimedia tablets will be the first Wi-Fi clients to adopt 802.11ac. Employees are bringing the devices into the enterprise, and organisations need to add secure guest access for them or integrate them into the corporate network securely. The new enterprise wireless LAN infrastructure needs to provide the capacity and quality of service demanded by these devices. 802.11ac will provide better coverage in the 5 GHz band, increased capacity, support for more devices of all types and improved reliability in harsh environments.

IEEE 802.11ac will replace IEEE 802.11n: The two standards will actually complement each other. 802.11n will not be replaced because it is needed to support the 2.4 GHz band. 802.11ac will be an upgrade to the 5 GHz portion of the enterprise wireless LAN. Most enterprise Wi-Fi systems will support both standards for many years to come. 802.11ac can be inserted by replacing existing APs with dual-radio (802.11n and 802.11ac) APs or 802.11ac products can be installed as a network overlay.

IEEE 802.11ac is for high-powered, gigabit-per-second clients only: A lot of the excitement about the 802.11ac standard is about breaking the gigabit barrier - Wi-Fi supporting single-station throughput greater than a gigabit per second. But 802.11ac is much more than a speed bump and the improvements are targeted at many different classes of Wi-Fi devices. 802.11ac will bring significant benefits for next-generation, low-power Wi-Fi clients such as smartphones. A single stream 802.11ac smartphone will be able to transmit three times more data using the same power or less. Wireless LAN infrastructures based on 802.11ac will be able to support multiple 802.11ac devices at the same time in the same channel, making more effective use of the spectrum.

IEEE 802.11ac will require a ‘rip and replace’: Not necessarily. In many implementations, the network software - such as the network operating system and network management application - will operate on the same computing systems used in today’s networks. Only the APs will be candidates for replacement and that will depend solely on a site’s requirements. 802.11ac may be introduced as an overlay to an existing 802.11n network, retained to support 2.4 GHz b/g/n devices.

Summary

IEEE 802.111 will deliver very high throughput for streaming multimedia devices, improvements in range, expanded system capacity and network resilience to interference. This will boost application performance for any enterprise with a high density of mobile devices. The BYOD trend will compel enterprise networks to support 802.11ac. Fortunately, 802.11ac technology can be easily integrated into an enterprise’s existing Wi-Fi network and will add the bandwidth to support the influx of Wi-Fi devices.

*Dr Jacek Kowalski has held the position of Chief Innovation Officer at Wavelink since 2010. He has more than 25 years of diverse ICT experience. Before joining Wavelink, Kowalski was at Docomo Intertouch where he was the director of technology convergence, South Pacific. Prior to that, Kowalski was the chief technology officer at Azure Wireless.