802.11ac update

I briefly mentioned 802.11ac a while ago here however a little more information is now available. At CES this year some vendors demonstarted 802.11ac products. Notably Buffalo with a prototype running a Broadcom chipset. Although this had a mighty 800mbps throughput that really is the tip of the iceberg.

A few highlights.

• 802.11ac should be backwards compatible with 802.11a/n.
• Channel widths will be 80 or 160MHz (802.11n can use 40MHz wide channels) now it remains to be seen exactly which channels these will be and how that can be worked into the current regulatory domains around the world.
• Support for 8 spatial streams compared to 802.11n 4 spatial streams. If like 802.11n initial products wont be the full bore 8 spatial streams however and similarly to 802.11n that may be a theoretical maximum, nobody has commercialised a 4 spatial stream device and there are only a few vendors with 3 spatial stream access points.
• A massive 256 QAM against 64 QAM for 802.11n.
• There will be compatability mechanisms for 802.11ac to coexist with 20 and 40MHz 802.11a/n
• Lets not forget MU-MIMO which will let us have multiple devices receiving from a single signal.
• Ultimately we all want to know how fast, well 6.93Gbps.

I feel it will certainly speed up the adoption of the 5.0GHz technology, I only hope it does not become as congested as the 2.4GHz spectrum however this may be the leading technology of the future so simply it will be everywhere, consumer electronis included. That will present its own challenges again as we try to support a greater level of legacy devices.

It certainly bodes for an interesting future as a wireless engineer.

Standards Update 802.11n Download

By far the most important change to wireless ever the 802.11n standard is now available for free download.

As from my previous blog I gave details of all the wireless standards that are freely available this should certainly be added to your collection.

It can be downloaded here

http://standards.ieee.org/getieee802/download/802.11n-2009.pdf

For the other standards here is a link to my previous post which is updated with the 802.11n standard

http://petenugent.blogspot.com/2010/04/wireless-standards.html

Faster than 802.11n meet 802.11ac

Just as you thought you could breath a little easier in this fast paced wireless world that we live in there's a new kid on the block, well a new standard in the making and it will be here sooner than you think. Yes another new standard.

I can recall when I got my first 802.11g access points and panic set in about compatibility with the 802.11b we already had installed. I needn't have worried but I was still a novice. I didn't even know at that time about 802.11 or 802.11a.

A little history, the 802.11 standard was minted in 1997 provisioning 1 Mbps and 2 Mbps in the 2.4 GHz spectrum, I know it seems along time ago but it had a decent uptake in manufacturing and warehousing. Only 2 years later 802.11b and 802.11a came along, that’s 1999. 802.11a provisioned up to 54 Mbps but was slow to capture the market due to generic client support. 802.11b on the other hand took off and everything was built with 802.11b that could be. We all know the advantages of 802.11a over 802.11b, higher throughput, less congestion etc but client support meant 802.11b stormed the market. Then 802.11g came along in 2003 and there was even less need to move to 802.11a as 802.11g in the 2.4 GHz spectrum was as fast as 802.11a and more accessible.

We waited an awfully long time for 802.11n with many many false dawns, it finally became a standard on September 11th 2009, about tea time if I recall, well that’s when I got the news. Just for the record 802.3af became a standard on the same day but was eclipsed by the hoopla surrounding 802.11n.

802.11n was so different its a whole new set of rules for us wireless engineers to learn, channel bonding, MIMO, frame aggregation, block acknowledgements etc etc and promises up to 600 Mbps.

Well now we have 802.11ac, there is little out in the real world that goes into any great depth about this proposed new standard, however, it is being touted that it will be a standard in December 2012, that’s not far away at all.

All is not lost however as it seems that it will largely an evolution of 802.11n or at least some of the technologies. The basis for the enhanced speeds, over 1 Gbps, will be further channel bonding with talk of 80 MHz and even 160 MHz wide channels. Now it would appear that this would only be feasible in the 5.0 GHz spectrum as there are not enough reusable channels in the 2.4 GHz spectrum. Even with all the available channels in the 5.0 GHz spectrum it is unlikely that there would be enough non overlapping air space to deploy an enterprise cell based implementation as we do today. Slight improvements in modulation techniques will also push up the speed.

A major breakthrough could come in the form of MU-MIMO (multiple user MIMO) where simultaneous streams are given to users on the same channel.

Product may hit markets as early as next year however I get the general feeling that it will have more specific applications than 802.11n due to the channel bonding and would be ideal for streaming HD video or high speed PtP or PtmP implementations.

802.11ac also has a big sister, 802.11ad, similar technologies but working up to 60GHz where I believe there is a lot of spectrum available. This however would be severely limited in its signal propagation as we all know the higher the frequency the poorer the range so 60GHz is going to be working between two devices in relatively close proximity.

One thing is for sure, the wireless market place is technologically innovative and our jobs and skills will only be more valuable as we ride the crest of the wave.

Wireless Standards

I was looking for info on the next generation wireless standard 802.11ac and came across this.

http://www.ieee802.org/11/Reports/802.11_Timelines.htm

Its a good outline of all the current standards, ammendments and recommended practices and includes download links for some standards that are freely available.

I have thoughtfully copied the links to the download locations to save you the hassle of clicking everything and put in a few additional links that I could find.

IEEE 802.11: The WLAN standard was originally 1 Mbit/s and 2 Mbit/s, 2.4 GHz RF and infrared [IR] standard (1997), all the others listed below are Amendments to this standard, except for Recommended Practices 802.11F and 802.11T.

IEEE 802.11-2007 A new release of the standard that includes amendments a, b, d, e, g, h, i & j. (July 2007)

IEEE 802.11a-1999 54 Mbit/s, 5 GHz standard (1999, shipping products in 2001)

IEEE 802.11b-1999 Enhancements to 802.11 to support 5.5 and 11 Mbit/s (1999)

IEEE 802.11d-2001 International (country-to-country) roaming extensions (2001)

IEEE 802.11e-2005 Enhancements: QoS, including packet bursting (2005)

IEEE 802.11F-2003 Inter-Access Point Protocol (2003) Withdrawn February 2006

IEEE 802.11g-2003 54 Mbit/s, 2.4 GHz standard (backwards compatible with b) (2003)

IEEE 802.11h-2003 Spectrum Managed 802.11a (5 GHz) for European compatibility (2004)

IEEE 802.11i-2004 Enhanced security (2004)

IEEE 802.11j-2004 Extensions for Japan (2004)

IEEE 802.11k-2008 Radio resource measurement enhancements (2008)

IEEE 802.11n-2009 Higher throughput improvements using MIMO (multiple input, multiple output antennas) (September 2009)

IEEE 802.11p: WAVE—Wireless Access for the Vehicular Environment (such as ambulances and passenger cars) (working—June 2010)

IEEE 802.11r-2008 Fast BSS transition (FT) Working "Task Group r" (2008)

IEEE 802.11s: Mesh Networking, Extended Service Set (ESS) (working—September 2010)

IEEE 802.11T: Wireless Performance Prediction (WPP)—test methods and metrics Recommendation cancelled

IEEE 802.11u: Interworking with non-802 networks (for example, cellular) (working—September 2010)

IEEE 802.11v: Wireless network management (working—June 2010)

IEEE 802.11w-2009 Protected Management Frames (September 2009)

IEEE 802.11y-2008 3650–3700 MHz Operation in the U.S. (2008)

IEEE 802.11z: Extensions to Direct Link Setup (DLS) (August 2007 – December 2011)

IEEE 802.11aa: Robust streaming of Audio Video Transport Streams (March 2008 – June 2011)

IEEE 802.11ac: Very High Throughput <6 GHz; potential improvements over 802.11n: better modulation scheme (expected ~10% throughput increase); wider channels (80 or even 160MHz), multi user MIMO; (September 2008 – December 2012)

IEEE 802.11ad: Very High Throughput 60 GHz (December 2008 – December 2012)

IEEE 802.11ae: QoS Management

IEEE 802.11af: TV Whitespace

IEEE 802.11mb: Maintenance of the standard. Will become 802.11-2011. (Expected publication 8/02/11)

For those withh some money to spare at the end of all the books and lab gear you will be buying 80211n