IEEE 802.11ac

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IEEE 802.11ac is a wireless networking standard in the 802.11 family (which is marketed under the brand name Wi-Fi), developed in the IEEE Standards Association process,[1] providing high-throughput wireless local area networks (WLANs) on the 5 GHz band.[1] The standard was developed from 2011 through 2013 and approved in January 2014.[1][2]

This specification has expected multi-station WLAN throughput of at least 1 gigabit per second and a single link throughput of at least 500 megabits per second (500 Mbit/s). This is accomplished by extending the air interface concepts embraced by 802.11n: wider RF bandwidth (up to 160 MHz), more MIMO spatial streams (up to eight), downlink multi-user MIMO (up to four clients), and high-density modulation (up to 256-QAM).[3][4]

New technologies[edit]

New technologies introduced with 802.11ac include the following:[4]

  • Extended channel binding
    • Mandatory 80 MHz channel bandwidth for stations (vs. 40 MHz maximum in 802.11n), 160 MHz available optionally
  • More MIMO spatial streams
    • Support for up to eight spatial streams (vs. four in 802.11n)
  • Downlink Multi-user MIMO (MU-MIMO, allows up to four simultaneous downlink MU-MIMO clients)
    • Multiple STAs, each with one or more antennas, transmit or receive independent data streams simultaneously
      • “Space Division Multiple Access” (SDMA): streams not separated by frequency, but instead resolved spatially, analogous to 11n-style MIMO
    • Downlink MU-MIMO (one transmitting device, multiple receiving devices) included as an optional mode
  • Modulation
    • 256-QAM, rate 3/4 and 5/6, added as optional modes (vs. 64-QAM, rate 5/6 maximum in 802.11n)
  • Other elements/features
    • Beamforming with standardized sounding and feedback for compatibility between vendors (non-standard in 802.11n made it hard for beamforming to work effectively between different vendor products)
    • MAC modifications (mostly to support above changes)
    • Coexistence mechanisms for 20/40/80/160 MHz channels, 11ac and 11a/n devices
    • Adds four new fields to the PPDU header identifying the frame as a Very High Throughput (VHT) frame as opposed to 802.11n's High Throughput (HT) or earlier. The first three fields in the header are readable by legacy devices to allow coexistence

Meru Networks has suggested that 802.11ac makes a wireless network employing the Single Channel Architecture substantially more effective.[5] Traditional 802.11 networks are deployed as a Multiple Channel Architecture

Mandatory and optional features[edit]

  • Mandatory features (carried over from 802.11a/802.11g)
  • New mandatory features (newly introduced in 802.11ac)
    • 80 MHz channel bandwidths
  • Optional features (carried over from 802.11n)
  • Optional features (newly introduced in 802.11ac)
    • 5 to 8 spatial streams
    • 160 MHz channel bandwidths (contiguous 80+80)
    • 80+80 MHz channel bonding (discontiguous 80+80)
    • MCS 8/9 (256-QAM)

New scenarios and configurations[edit]

The single-link and multi-station enhancements supported by 802.11ac enable several new WLAN usage scenarios, such as simultaneous streaming of HD video to multiple clients throughout the home, rapid synchronization and backup of large data files, wireless display, large campus/auditorium deployments, and manufacturing floor automation.[6]

With the inclusion of USB 3.0 interface, 802.11ac access points and routers can use locally attached storage to provide various services that fully utilize their WLAN capacities, such as video streaming, FTP servers, and personal cloud services.[7] With storage locally attached through USB 2.0, filling the bandwidth made available by 802.11ac was not easily doable.

Example configurations[edit]

All rates assume 256-QAM, rate 5/6:

Scenario Typical Client
Form Factor
PHY Link Rate Aggregate
Capacity
(Speed)
1-antenna AP, 1-antenna STA, 80 MHz Handheld 433 Mbit/s 433 Mbit/s
2-antenna AP, 2-antenna STA, 80 MHz Tablet, Laptop 867 Mbit/s 867 Mbit/s
1-antenna AP, 1-antenna STA, 160 MHz Handheld 867 Mbit/s 867 Mbit/s
2-antenna AP, 2-antenna STA, 160 MHz Tablet, Laptop 1.69 Gbit/s 1.69 Gbit/s
4-antenna AP, four 1-antenna STAs, 160 MHz
(MU-MIMO)
Handheld 867 Mbit/s to each STA 3.39 Gbit/s
8-antenna AP, 160 MHz (MU-MIMO)
-- one 4-antenna STA
-- one 2-antenna STA
-- two 1-antenna STAs
Digital TV, Set-top Box,
Tablet, Laptop, PC, Handheld
3.39 Gbit/s to 4-antenna STA
1.69 Gbit/s to 2-antenna STA
867 Mbit/s to each 1-antenna STA
6.77 Gbit/s
8-antenna AP, four 2-antenna STAs, 160 MHz
(MU-MIMO)
Digital TV, Tablet, Laptop, PC 1.69 Gbit/s to each STA 6.77 Gbit/s

Data rates and speed[edit]

Theoretical[edit]

Theoretical throughput for single Spatial Stream (in Mbit/s)
MCS
index
Modulation
type
Coding
rate
20 MHz channels 40 MHz channels 80 MHz channels 160 MHz channels
800 ns GI 400 ns GI 800 ns GI 400 ns GI 800 ns GI 400 ns GI 800 ns GI 400 ns GI
0 BPSK 1/2 6.5 7.2 13.5 15 29.3 32.5 58.5 65
1 QPSK 1/2 13 14.4 27 30 58.5 65 117 130
2 QPSK 3/4 19.5 21.7 40.5 45 87.8 97.5 175.5 195
3 16-QAM 1/2 26 28.9 54 60 117 130 234 260
4 16-QAM 3/4 39 43.3 81 90 175.5 195 351 390
5 64-QAM 2/3 52 57.8 108 120 234 260 468 520
6 64-QAM 3/4 58.5 65 121.5 135 263.3 292.5 526.5 585
7 64-QAM 5/6 65 72.2 135 150 292.5 325 585 650
8 256-QAM 3/4 78 86.7 162 180 351 390 702 780
9 256-QAM 5/6 N/A N/A 180 200 390 433.3 780 866.7

Note: A second stream doubles the theoretical data rate, a 3rd 3x, etc. Note: MCS 9 is not applicable to all channel width/spatial stream combinations

Advertised[edit]

Type 2.4 GHz Mbit/s[A] 5 GHz Mbit/s
AC600 150 433
AC750 300 450
AC1200 300 867
AC1300 400 867
AC1450 450 975
AC1600 300 1,300
AC1750 450 1,300
AC1900 600[B] 1,300
AC2350 600[B] 1,733
AC3200 600[B] 2,600
A.1 802.11ac only specifies operation in the 5 GHz band. Operation in the 2.4 GHz band is specified by 802.11n.
B.1 2 3 With 802.11n, 600 Mbit/s in the 2.4 GHz band can be achieved by using four spatial streams at 150 Mbit/s each. As of September 2014, commercially available devices that achieve 600 Mbit/s in the 2.4 GHz band use 3 spatial streams at 200 Mbit/s each.[8][9] This requires the use of 256-QAM modulation, which is not compliant with 802.11n and can be considered a proprietary extension.[9]

Products[edit]

Commercial routers and access points[edit]

Quantenna released the first 802.11ac chipset for retail Wi-Fi routers and consumer electronics on November 15, 2011.[10] Redpine Signals released the first low power 802.11ac technology for smartphone application processors on December 14, 2011.[11] On January 5, 2012, Broadcom announced its first 802.11ac Wi-Fi chips and partners[12] and on April 27, 2012, Netgear announced the first Broadcom-enabled router.[13] On May 14, 2012, Buffalo Technology released the world’s first 802.11ac products to market, releasing a wireless router and client bridge adapter.[14] On December 6, 2012, Huawei announced commercial availability of the industry's first enterprise-level 802.11ac Access Point.[15]

Apple Inc. is selling 802.11ac versions of its AirPort Extreme and AirPort Time Capsule products.[16] Motorola Solutions is selling 802.11ac access points including the AP 8232.[17] In April 2014, Hewlett-Packard started selling the HP 560 access point in the controller-based WLAN enterprise market segment.[18]

Commercial laptops[edit]

On June 7, 2012, it was reported that ASUS had unveiled its ROG G75VX gaming notebook, which will be the first consumer-oriented notebook to be fully compliant with 802.11ac[19] (albeit in its "draft 2.0" version).

Hewlett-Packard as of December 2013 incorporates 802.11ac compliance in laptop computers.[20]

Apple announced in June 2013 that the new MacBook Air features 802.11ac wireless networking capabilities,[21][22] later announcing in October 2013 that the MacBook Pro and Mac Pro also featured 802.11ac.[23][24]

Commercial handsets[edit]

Vendor Model Release Date Chipset Notes
HTC One (2013) March 2013[25] BCM4335 [26] First 802.11ac-enabled handset announced February 19, 2013[27]
Samsung Galaxy S4 April 26, 2013 BCM4335 [28]
Samsung Galaxy Note 3 September 25, 2013 BCM4339 [29] Subsequent Devices Include 802.11ac
LG LG Nexus 5 October 2013[30] BCM4339 [31] BCM4339 is the updated version of the BCM4335
Nokia Lumia 1520 November, 2013[32] WCN3680 First 802.11ac-enabled Windows Phone
Nokia Lumia Icon February 20, 2014[33] WCN3680 Lumia 930 is Europe version of the same phone, also with 802.11ac
HTC One (M8) March 25, 2014 WCN3680 [34]
Samsung Galaxy S5 April 11, 2014 BCM4354
LG G3 May 23, 2014 BCM4339 [35]
Amazon.com Fire Phone July 25, 2014 [36] WCN3680 [37]
Samsung Galaxy S5 Prime/SM-G906S June 18, 2014 QCA6174
Apple iPhone 6 September 19, 2014 First 802.11ac-enabled iOS device, along with iPhone 6 Plus
Apple iPhone 6 Plus September 19, 2014 First 802.11ac-enabled iOS device, along with iPhone 6
Motorola Nexus 6 October 16, 2014 Qualcomm Snapdragon 805 [38]

Commercial tablets[edit]

Vendor Model Release Date Chipset Notes
Apple iPad Air 2 October 24, 2014 First 802.11ac-enabled iOS tablet device
Microsoft Surface Pro 3 June 20, 2014 802.11ac-enabled touchscreen computing device

Chipsets[edit]

Vendor Part # Streams LDPC TxBF 256-QAM Applications
Broadcom BCM43602 3 Yes Yes Yes routers, laptops
Broadcom BCM4360 3 Yes Yes Yes routers, laptops
Broadcom BCM43569 2 Yes Yes Yes DTV
Broadcom BCM4352 2 Yes Yes Yes tablets
Broadcom BCM4350 2 Yes Yes Yes tablets
Broadcom BCM4356 2 Yes Yes Yes handsets, tablets
Broadcom BCM4354 2 Yes Yes Yes handsets, tablets
Broadcom BCM4339 1 Yes Yes Yes handsets
Broadcom BCM4335 1 Yes Yes Yes handsets
Intel 7260 AC 2 No Yes ? laptops, desktops
Intel 3160 AC 1 No Yes ? laptops
Marvell Avastar 88W8897 2 Yes Yes Yes tablets
Marvell Avastar 88W8864 3 Yes Yes Yes routers
Qualcomm WCN3680 1 Yes Yes Yes handsets
Qualcomm QCA9862 2 Yes No Yes tablets
Qualcomm QCA9880 3 Yes No Yes home routers
Qualcomm QCA9890 3 Yes Yes Yes enterprise routers
Qualcomm QCA9892 2 Yes Yes Yes tablets, PtP Links
MediaTek MT7610 1 ? ? ? PC (PCIe or USB)
MediaTek MT7650 1 ? Yes Yes handsets
MediaTek MT7612E 2 Yes Yes Yes laptops (PCIe 2.0)
MediaTek MT7612U 2 Yes Yes Yes laptops (USB 3.0)
Quantenna QAC2300 4 Yes Yes Yes routers
Redpine Signals RS9117 1 Yes ? Yes handsets
Redpine Signals RS9333 3 Yes ? Yes routers
Realtek RTL8811AU 1 ? ? ? adapter (USB 2.0)
Realtek RTL8812AU 2 ? ? ? adapter (USB 3.0)

See also[edit]

References[edit]

  1. ^ a b c "Official IEEE 802.11 Working Group Project Timelines". 2012-11-03. 
  2. ^ Kelly, Vivian (2014-01-07). "New IEEE 802.11ac™ Specification Driven by Evolving Market Need for Higher, Multi-User Throughput in Wireless LANs". IEEE. Retrieved 2014-01-11. 
  3. ^ Kassner, Michael (2013-06-18). "Cheat sheet: What you need to know about 802.11ac". TechRepublic. Retrieved 2013-06-20. 
  4. ^ a b "802.11ac: A Survival Guide". Chimera.labs.oreilly.com. Retrieved 2014-04-17. 
  5. ^ "Can Single Channel Really Work?". Blog.merunetworks.com. 2013-07-17. Retrieved 2014-04-17. 
  6. ^ de Vegt, Rolf (2008-11-10). "802.11ac Usage Models Document". 
  7. ^ "ASUS RT-AC56U & USB-AC56 802.11AC Review". Hardwarecanucks.com. Retrieved 2014-04-24. 
  8. ^ Ganesh, T S (2014-09-02). "Netgear R7500 Nighthawk X4 Integrates Quantenna 4x4 ac Radio and Qualcomm IPQ8064 SoC". anandtech.com. Retrieved 2014-09-08. 
  9. ^ a b Higgins, Tim (2013-10-08). "AC1900: Innovation or 3D Wi-Fi?". smallnetbuilder.com. Retrieved 2014-09-08. 
  10. ^ "Quantenna Launches World's First 802.11ac Gigabit-Wireless Solution for Retail Wi-Fi Routers and Consumer Electronics" (Press release). Quantenna. 2011-11-15. 
  11. ^ "Redpine Signals Releases First Ultra Low Power 802.11ac Technology for Smartphone Application Processors" (Press release). Redpine Signals. 2011-12-14. Retrieved 2013-03-15. 
  12. ^ "Broadcom Launches First Gigabit Speed 802.11ac Chips - Opens 2012 CES with 5th Generation (5G) Wi-Fi Breakthrough" (Press release). Broadcom. 2012-01-05. Retrieved 2013-03-15. 
  13. ^ "Netgear's R6300 router is first to use Broadcom 802.11ac chipset, will ship next month for $200". Engadget. Retrieved 10 September 2014. 
  14. ^ "Buffalo's 802.11ac Wireless Solutions Available Now" (Press release). Austin, Texas: Buffalo Technology (via PRNewswire). May 14, 2012. Retrieved 2013-03-15. 
  15. ^ "Huawei Announces Commercial Availability of Industry’s First Enterprise-level 802.11ac Access Point". Huawei. 6 December 2012. 
  16. ^ "Apple - Mac - Airport Express". Retrieved 10 September 2014. 
  17. ^ AP 8232 Modular 802.11n Access Point - Motorola Solutions USA
  18. ^ "HP Launches the HP 560 802.11ac Access Point". HP. 2014-03-31. 
  19. ^ "Asus gaming notebook first to feature full 802.11ac". Electronista. 2012-06-07. Retrieved 2013-03-15. 
  20. ^ "HP ENVY TouchSmart 17-j043cl Notebook PC Product Specifications HP ENVY TouchSmart 17-j043cl Notebook PC | HP Support". H10025.www1.hp.com. Retrieved 2014-04-17. 
  21. ^ "Apple unveils new MacBook Air lineup with all-day battery life, 802.11ac Wi-Fi". AppleInsider. 2013-06-11. Retrieved 2013-06-11. 
  22. ^ "Apple - Macbook Air". Retrieved 10 September 2014. 
  23. ^ "MacBook Pro with Retina display - Technical Specifications". Apple. Retrieved 10 January 2014. 
  24. ^ "Mac Pro - Technical Specifications". Apple. Retrieved 10 January 2014. 
  25. ^ "HTC One specs". 
  26. ^ "BCM4335". 
  27. ^ "HTC One specs". 
  28. ^ "BCM4335". 
  29. ^ "Samsung Galaxy Note 3 Review". 
  30. ^ "LG Nexus 5". 
  31. ^ "iFixIt Nexus 5 Teardown". 
  32. ^ "Nokia Lumia 1520". Nokia. Retrieved 2014-11-10. 
  33. ^ "Nokia Lumia Icon". Nokia. Retrieved 2014-11-10. 
  34. ^ "HTC One(M8) Teardown". 
  35. ^ "LG G3 Teardown". 
  36. ^ "Amazon Fire Phone". 
  37. ^ "Amazon Fire Phone Teardown". 
  38. ^ "Nexus 6". 

External links[edit]