A new IEEE standard is in the wings ready to make its debut on the wireless market stage: 802.11ac.
802.11ac builds upon the success of 802.11n which is now the predominant WLAN standard in the market. 802.11n brought improvements in data rates and link efficiencies; however, consumer and commercial trends have created demand for a new set of capabilities which are addressed by 802.11ac (see Table 1).
Table 1 - 802.11ac Major Features Enhancements
|802.11ac Features||Customer Benefits|
|Wider channels||Higher data rates – up to 1.3Gbps per radio|
|Higher encoding density||Higher bit density per packet|
|Increased number of spatial streams||Higher data rates per AP/client link|
|Beamforming||Greater wireless AP/client link reliability|
|Multi-user MIMO||Greater AP/client capacity and efficient use of spectrum|
The cumulative benefit of 802.11ac features will enable Wi-Fi solutions to meet today’s demand for high capacity and high quality mobile real-time applications like video and voice.
|802.11ac White Paper - Understanding the New IEEE Standard|
Why is 802.11ac needed?
As the commercial population becomes more mobile, two trends have emerged for Wi-Fi solutions to address:
- Mobile applications now demand more bandwidth – Video and voice applications have increased the demand for pervasive bandwidth…everywhere.
- Individuals carry multiple wireless devices – With an average corporate mobile device/user ratio approaching 2.7 (laptop, tablet, and/or smartphone), client congestion has become a problem for wireless networks.
The challenge for 802.11ac is to meet today’s functional demands and the explosive wireless market growth that is expected over the next three to five years.
|IDC Tech Brief - The Promise of 802.11ac|
The 802.11ac standard addresses these new business requirements to achieve the goal of higher data rate and greater link reliability by sophisticated RF architectural enhancements that include:
- Wider channel support – 802.11ac mandates support of 80MHz wide channels with optional 160MHz wide channels to achieve higher data rates than are achieved with 802.11n.
Table 2 - 802.11ac Data Rates by Channel Width
|# Spatial Streams||20 MHz||40 MHz||80 MHz||160 MHz|
|1||86 Mbps||200 Mbps||433 Mbps||866 Mbps|
|2||173 Mbps||400 Mbps||866 Mbps||1.73 Gbps|
|3||288.9 Mbps||600 Mbps||1.3 Gbps||2.34 Gbps|
|4||346.7 Mbps||800 Mbps||1.73 Gbps||3.46 Gbps|
Achieving higher data rates, however, comes at a cost: fewer available channels in the 5 GHz band. With 802.11a, there are a total of 24 non-overlapping channels available, but with 802.11ac, achieving the maximum data rate possible reduces that number to two for 80MHz and only one for 160 MHz wide channels.
|Maximize Channel Availability|
Table 3 - Available 802.11ac Channels
|Including DFS*||Excluding DFS|
* DFS = Dynamic Frequency Selection – for avoiding interference with Weather Radar
Achieving maximum data rates with 802.11ac can be an insurmountable “coverage” challenge for traditional Wi-Fi vendors (see Table 3) for whom it is imperative to have at least three non-overlapping channels for adequate pervasive coverage. Meru’s technology is built with a single channel architecture and can maximize the performance and coverage of a 802.11ac-class solution, making Meru the de facto vendor able to deploy facility-wide solutions.
|802.11ac Technical Overview|
The other optimizations in 802.11ac also include:
- Denser amplitude modulation – 256-QAM - four times denser than 802.11n further increasing the bit rate density achieved by 802.11ac. (Video)
- More spatial streams - up to eight spatial streams, further increasing the data rate for each radio. (Note that first-generation silicon will support only three spatial streams.)
- Beamforming to fortify RF connections – increases reliability of the AP/client link.
- Multi-user MIMO – supports simultaneous transmissions to multiple clients and maximizes RF band utilization. Up to four distinct clients can receive data simultaneously from a single AP at full channel data rate.
Timetable for commercial availability of 802.11ac
Industry availability of commercial products will precede the ratification of the standard. The IEEE task group projects no functional changes to the specification, so Wi-Fi vendors are proceeding with plans to release products in mid-2013 (see below).
Because the 802.11ac standard has modified the RF physical and MAC layer specification, deployment of an 802.11ac-based network will require the purchase of new access points. The availability of 802.11ac, however, does not make 802.11n products obsolete because there remains a strong requirement for supporting 2.4GHz mobile devices. Enterprise deployments of 802.11ac will have to consider support for 2.4GHz.
802.11ac deployment strategies
Purchase and integration of 802.11ac will involve three decision points:
- When to buy. 802.11n meets about 80-90% of the bandwidth demand of today’s mobile applications. In most cases, the on-boarding of applications like tele-presence and voice will trigger the decision to buy 802.11ac.
- Once a buy decision has been made, the next decision must be how to deploy 802.11ac to best provide for continued support of 2.4GHz devices. An 802.11ac deployment might mean a “forklift” replacement of older 802.11n equipment with dual-radio/dual-mode 802.11ac products or it might mean deploying an 802.11ac-only solution as an overlay to an existing 802.11n network. Either way, there will be a CAPEX factor to address.
- A decision must then be made on how pervasive is the need for Very High Throughput (VHT). One strategy would involve deploying VHT hotspots only where localized higher data rates or client density is required. Meru’s single channel architecture greatly simplifies this decision to extend VHT support pervasively throughout a facility.
|Top Considerations when Upgrading to 802.11ac|
Meru technology is designed to maximize the benefit of 802.11ac
- Meru’s single-channel architecture is not limited by reduced channel availability in order to maximize wireless RF coverage.
- Meru can further maximize RF resources through channel layering – compounding RF resource availability.
- AP 832 is the fastest wireless access point on the market - two AC radios with 80 MHz Single Channel supporting 1.3 Gbps radio
- Highest client density using channel layering
- Low power design - supports full radio configuration on 802.3af
- Best Value
- Low cost - only $100 in cost between Meru's 802.11n access point price point
- Lowest cost per Mbps data rate per access point
Traditional Wi-Fi deployments were designed with availability of three or more channels and required site surveys for each installation or upgrade. In such cases, 802.11ac deployments may only support a concept of “islands” of VHT, limiting high data rate access to certain fixed locations within a facility. Meru, on the other hand, is designed to exploit limited channel availability - even in the case of a single 160MHz channel because of our single channel architecture.
802.11ac is here and the new standard is focused on:
- Extending the usability of a wireless LAN to a broader set of high-data rate applications.
- Supporting higher client density.
- Contributing to increased productivity and lower network TCO.
Because of Meru’s unique single-channel architecture, an investment in a Meru 802.11ac solution allows you to remain mobile and have continuous access to VHT throughout a facility. Meru is leading the charge to deliver a robust 802.11ac offering. Our goal is to provide the most advanced Wi-Fi network solution in the market, so that your organization can reap the full benefits of 802.11ac and thrive.