Cheat sheet: What you need to know about 802.11ac

By Michael Kassner in Data Center, June 26, 2013, 7:30 AM

The newest wireless networking protocol is 802.11ac, due to be ratified sometime in 2013. Michael Kassner does the research and tells you what you need to know.

[UPDATE 06-26-2013: See below for addition of transmission testing results]

Wi-Fi junkies, people addicted to streaming content, and Ethernet-cable haters are excited. There's a new Wi-Fi protocol in town, and vendors are starting to push products based on the new standard out the door. It seems like a good time to meet 802.11ac, and see what all the excitement's about.

What is 802.11ac?

802.11ac is a brand new, soon-to-be-ratified wireless networking standard under the IEEE 802.11 protocol. 802.11ac is the latest in a long line of protocols that started in 1999:

802.11b provides up to 11 Mb/s per radio in the 2.4 GHz spectrum. (1999)
802.11a provides up to 54 Mb/s per radio in the 5 GHz spectrum. (1999)
802.11g provides up to 54 Mb/s per radio in the 2.4 GHz spectrum (2003).
802.11n provides up to 600 Mb/s per radio in the 2.4 GHz and 5.0 GHz spectrum. (2009)
802.11ac provides up to 1000 Mb/s (multi-station) or 500 Mb/s (single-station) in the 5.0 GHz spectrum. (2013?)

802.11ac is a significant jump in technology and data-carrying capabilities. The following slide compares specifications of the 802.11n (current protocol) specifications with the proposed specs for 802.11ac.

(Slide courtesy of Meru Networks)

What is new and improved with 802.11ac?

For those wanting to delve deeper into the inner workings of 802.11ac, this Cisco white paper should satisfy you. For those not so inclined, here's a short description of each major improvement.

Larger bandwidth channels: Bandwidth channels are part and parcel to spread-spectrum technology. Larger channel sizes are beneficial, because they increase the rate at which data passes between two devices. 802.11n supports 20 MHz and 40 MHz channels. 802.11ac supports 20 MHz channels, 40 MHz channels, 80 MHz channels, and has optional support for 160 MHz channels.

(Slide courtesy of Cisco)

More spatial streams: Spatial streaming is the magic behind MIMO technology, allowing multiple signals to be transmitted simultaneously from one device using different antennas. 802.11n can handle up to four streams where 802.11ac bumps the number up to eight streams.

(Slide courtesy of Aruba)

MU-MIMO: Multi-user MIMO allows a single 802.11ac device to transmit independent data streams to multiple different stations at the same time.

(Slide courtesy of Aruba)

Beamforming: Beamforming is now standard. Nanotechnology allows the antennas and controlling circuitry to focus the transmitted RF signal only where it is needed, unlike the omnidirectional antennas people are used to.

(Slide courtesy of Altera.)

What's to like?

It's been four years since 802.11n was ratified; best guesses have 802.11ac being ratified by the end of 2013. Anticipated improvements are: better software, better radios, better antenna technology, and better packaging.

The improvement that has everyone charged up is the monstrous increase in data throughput. Theoretically, it puts Wi-Fi on par with gigabit wired connections. Even if it doesn't, tested throughput is leaps and bounds above what 802.11b could muster back in 1999.

Another improvement that should be of interest is Multi-User MIMO. Before MU-MIMO, 802.11 radios could only talk to one client at a time. With MU-MIMO, two or more conversations can happen concurrently, reducing latency.

What do experts say about 802.11ac?

There is a lot of guessing going on as to how 802.11ac pre-ratified devices are performing. I don't like to guess, so I contacted Steve Leytus, my Wi-Fi guy who also owns Nuts about Nets, and asked him what he thought:

Regarding 802.11ac, we are testing wireless game consoles for a large company in the Seattle area. We test performance using 20, 40, and 80 MHz channels. During the tests, we stream video data and monitor the rate of packet loss in the presence of RF interference or 802.11 congestion.

802.11ac's primary advantage is support for the 80 MHz-wide channel. And without question, the wider channel can stream more data. But, as with everything, there are trade-offs.

I asked Steve what the trade-offs were:

I don't think you'll find 802.11ac clients as standard equipment for computers. So, you need to buy one, connect it to the computer via Ethernet, configure the client, and finally pair the client with the router/access point.
Unless your application requires streaming large amounts of data, you probably will not experience a noticeable improvement in performance.
The 80 MHz-wide channel is more susceptible to RF interference or congestion from other Wi-Fi channels by virtue of its larger width.
The 80 MHz channel eats up four of the available channels in the 5.0 GHz band. Some routers implement DCS (dynamic channel selection) whereby they will jump to a better channel in the presence of RF interference. But if you are using 80 MHz channels your choices for better channels are few or non-existent.

Transmission testing results

[UPDATE] Steve Leytus finally was able to break away from his testing long enough to grab screen shots of the three channel widths. I haven't seen this anywhere else, so I thought I'd pass his explanation and slides along:

The three images are of iperf transmitting from one laptop to another at 20 Mbps; both laptops are connected to the same Buffalo 802.11ac router -- one laptop is connected via Ethernet, and the other is associated wirelessly. The transmission test was repeated three times using channel widths of 20 MHz, 40 MHz, and 80 MHz.

You can clearly see how the width of the spectrum trace increases with channel width. The other thing to notice which might not be so apparent is the power level -- as the channel width increases the power level decreases.

This is expected since the transmit power has to be spread out over a wider frequency range. The implication is that as the channel width increases then the distance the signal can reach probably decreases.

20 MHz

40MHz

80 MHz

What is my concern?

First let's gets some physics out of the way (Courtesy of Attenuation of Microwave Signal and Its Impact on Communication Systems [PDF]):

The higher the frequency (5.0 GHz versus 2.4 GHz), the greater the bandwidth which allows more data carrying capacity.
Attenuation is the reduction of signal strength during transmission.
RF signals are attenuated exponentially over distance.
Attenuation is directly proportional to the frequency.

My concern rides on 802.11ac needing to use the 5.0 GHz frequency range in order to get the monster data throughput being advertised. That means -- per the physics above -- users will have to live with a significantly smaller coverage area, something those more familiar with 2.4 GHz devices will not expect.

Final thoughts

I have been checking out the forums and early reactions seem mixed. That might be indicative of the sensitivity of each user's situation and physical surroundings when considering how well 802.11ac devices perform. Other than my coverage-area concern, my only other thought: there will always be a bottleneck. And unless you are one of the fortunate connected to Google Fiber, the Internet connection will be it.

About Michael Kassner

Michael Kassner is currently a systems manager for an international company. Together with his son, he runs MKassner Net, a small IT publication consultancy.

55 comments

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mhammett

FYI: The comments section doesn't work as smoothly in Chrome as it does in IE. Might want to address that. All of the speeds mentioned are the OTA (Over The Air) data rates. Real throughput is half of that. WiFi is very much a shared environment. Either one of those conditions means that 802.11ac will *NOT* be faster than gigabit Ethernet in ideal conditions In many conditions, it is likely to be barely above 100 meg Ethernet, due to poor RF conditions. Resolving the poor RF conditions will do far more towards more usable throughput than higher maximum throughput numbers. These high speeds are for enthusiasts, enterprises and service providers. Your average Joe in the home will not benefit from the increased speeds. If you were to remove the increasing modulation complexity, larger channels, etc. and just applied real, working beamforming to 802.11g, that would be sufficient for a significant number of homes. Yes, today's FIOS and Comcast connections would then require an n system to take advantage of the speeds over 25 megabit. I hope to God that the consumer routers come with a 20 MHz channel by default and not 80. Doing otherwise would just further pollute the RF environment. MU-MIMO will be great for enterprises and service providers. The latency over a Wi-Fi connection is negligible, but being able to send data to multiple clients simultaneously will be a great improvement for enterprises and service providers. It would be really nice if the APs had the intelligence to move problem clients to other, reduced chain count connections to mitigate their effect on total system performance. Frequency alone has nothing to do with bandwidth. All else equal, a 20 MHz channel at 500 MHz will pass as much data as a 20 MHz channel at 500 GHz. However, our spectrum allocation model is such that generally higher frequencies have larger amounts of spectrum allocated to them. This is due to as you go higher up in frequency, larger and larger frequency deltas are required for any noticeable change in how that frequency acts. 50 MHz and 5,050 MHz behave VERY differently. 50 MHz will go through just about any material other than Mother Earth herself (well, and bodies of water), while 5,050 MHz can't escape a concrete room or a metal shed or a tree line. 50 GHz and 55 GHz face the same penetration challenges. I believe I have commented elsewhere on here already about how the frequency to attenuation graph isn't smooth. Many things in the atmosphere affect frequencies differently. http://www.phys.hawaii.edu/~anita/new/papers/militaryHandbook/rf_absor.pdf The same thing continues below 10 GHz, but it becomes less and less of a factor.

Michael Kassner

I am always glad when you add your insight to the mix.

chitsamatanga

Hie, finding it difficult to print your articles!! how do you print them?

DFagerstrom

Running in FireFox works for me--as far as copying text. From clipboard I past to Word 2003 format for later searchability.

Michael Kassner

If you would like email me, and I can send you a PDF copy.

WmRobt

My isp connection is 65Mb [and not all that fast] and I have tested connections to specific servers which confirm that; however connecting with a google page for example takes over 3 seconds all too often. Not picking on google same goes for most other [if not all] services I connect. Of course that includes loading the page as well. But I do?t care where the time is spent. It just takes too long and I dont see a faster wifi changing that.

andrew232006

My ISP sells me 7, I get 6 on good days and opening google is a few hundred milliseconds at most. Of course it doesn't matter if you have your connection saturated by other devices and programs. If I were you I'd test my internet speed on testmy.net with everything using the internet off to see just how much your ISP is lying with advertised speeds. You may also want to check your router for QoS capability which could be used to give http traffic priority over your other internet traffic.

Michael Kassner

You mirror my situation and response times.

Michael Kassner

I have either a 7 Mb DSL or 20Mb 4G Internet connection and I think they are fast. I wonder if there is something else going on with page loading locally.

Slayer_

Cause it seems n is still a fair bit slower than normal 100mbit wired connection.

Kim SJ

Having much experience of trying (and often failing) to make in-home WiFi work at 2.4GHz in the presence of devices like video repeaters, baby monitors, etc, I think there will be a big win for users with such issues. Afaiu, the "play nicely" rules are much better defined in the 5GHz band.

Michael Kassner

I had not heard that. There was very little specified as changed when it comes to the rules of engagement. Do you have some links you could share? But, you will have several more channels to choose from.

GrizzledGeezer

1 Like

...that 802.11ac is a solution for problems that many users aren't likely to have. It's also possible that the great configuration flexibility possible might cause installation and deployment problems. 802.11ac appears to be more-suitable for business than consumer use. Nothing wrong with that.

Michael Kassner

That 802.11ac is being built for those who shuffle a lot of data around "locally" and have multiple devices that will make use of the MU MIMO.

thomas4442

I didn't get into the nuts and bolts of wifi frequency. You guys took my layman's scenario and 11ac and went in-depth. Thanks! And yes Michael, I use 2.4 and wouldn't get the area with 11ac. For the last few years I've only had to deal with home networks and home users. I graduate soon, and then will likely deviate from my simple explanations. No way I could use the terminology used here for my current clients. I look forward to advancing into the enterprise arena. Thanks again.

Michael Kassner

It should be interesting to see how 802.11ac unfolds. Congratulations on graduating, and best of luck. We need more knowledgeable and vested people such as yourself helping us.

kfilius

"Good, Fast, Cheap: Pick any two (you can't have all three)" (RFC 1925) I love it.

Michael Kassner

Now, I need to know which two you'd pick.

andrew232006

Being 5GHz only makes me wonder how 802.11ac routers will work with wireless g and n devices. Support for those devices isn't something I'm willing to give up any time soon I'm currently stuck on 20mhz because many of my devices won't work with my router set to 40mhz. So I'm guessing none of my current devices will work on 80mhz or 160mhz.

Michael Kassner

It is my understanding that many of the vendors are going to have devices that support both 802.11n and 802.11ac frequency bands.

tackerm

I wanted to share my experience with available equipment as of 6/2013. I had to make a decision on a router to replace my old 11bgn router that died. Rather than spend $100 on a good 11n router, I decided instead to get an 11ac router for $175 to avoid replacing the 11n prematurely in the future. For various reasons, I chose the Asus RT-AC66u ac1750 gigabit router, which allows simultaneous connections of 450Mbps at 2.4ghz & 1.3Gbps at 5ghz (theoretically.) At 2.4ghz frequency, you can select channel bandwidth of 20 or 40Mhz. At the 5ghz frequency, you can select 20, 40 or 80Mhz bandwidth. You can also adjust transmission power up to 200mW, depending on local regulations. I wanted to comment that this equipment (& similar competitive offerings) is available now. Also, 11ac PCI & USB 3.0 adapters are available. I bought some 11ac USB dongles for $39 each for guest laptop computers. Can anyone suggest a practical way to test the bandwidth at 80 vs 40, so I can report back? Ping & speedtest.com seem to test my Comcast internet connection more than wireless bandwidth. I apologize in advance if anyone is offended by my naming of vendors or my lack of engineering knowledge.

mrobbins

Thanks for this article. A neat summary of the key points and concerns and well worth the time spent reading it. More like this please TechRepublic.

Henry 3 Dogg

"That means â per the physics above â users will have to live with a significantly smaller coverage area, something those more familiar with 2.4 GHz devices will not expect." Except that the beaming gives improved coverage range - also per the physics above. Having just replaced two 802.11n Airport Extremes with a single 802.11ac, I can tell you that the range is better.

Michael Kassner

I am glad that your situation improved. Just a FYI, many 802.11n devices had beamforming antennas as well. As an amateur radio operator who is familiar with both 2.4 GHz and 5.0GHz (hams have primary license in these frequency ranges): http://en.wikipedia.org/wiki/13-centimeter_band https://en.wikipedia.org/wiki/5_centimeter_band I know it takes significantly more power to go the same distance, "free-space propagation" using the higher frequency. My familiarity is with sat comms and working the ISS. I mentioned in the article, there are improvements in the equipment that may offset some of the attenuation, and could explain why you are having better luck with 802.11ac.

Henry 3 Dogg

"I donât think youâll find 802.11ac clients as standard equipment for computers." Heard of the MacBook Air?

Michael Kassner

Steve prefaced his statement with think. And he is the kind of guy that will gladly alter his stance with the information you provided. Thanks for letting us know.

georgeou

The 80 MHz quad-width channels are in the 5 GHz range which has anywhere from 12 to 24 independent channels. 2.4 GHz only has 3 independent channels so you have less congestion in 5 GHz using 80 MHz wide channels than using normal 20 MHz wide channels in 2.4 GHz. As for "Attenuation is directly proportional to the frequency", that's only half the equation. The other half of the equation is that a given antenna length is effectively twice as long for 5 GHz as it is for 2.4 GHz because it covers more wavelengths. That nullifies the increased attenuation and you get more or less the same range through air or through most materials. Some materials may block one frequency more than another frequency though most materials block 5 GHz slightly more than they block 2.4 GHz. Some materials like brick or stucco can block 5 GHz substantially more than 2.4 GHz. But more effectively blocking is an asset rather than a liability In the enterprise space because it allows for denser access point deployment and higher capacity. If higher range is needed, you can always use a higher (larger) gain antenna or a directional patch antenna to optimally shape the coverage.

Michael Kassner

It has been quite a while since you have commented on TR. Thanks for your input. You bring up a good point, George. It looks like at 80 MHz, 802.11ac will have five possible channels on 5.0 GHz. As for your comment on attenuation, it is not that simple according to my mentor, fellow amateur radio operator, and professor of advanced radio electronics at the University of MN. You have to address receiving and transmitting separately. When it comes to transmitting, a full wavelength antenna for 5.0 GHz will actually be "half" the size, not twice a 2.4 GHz antenna (2.4 GHz wavelength is 125 mm and 5.0 GHz wavelength is 59mm, both approximate as it depends on the actual frequency). And using a double wavelength antenna (size required for 2.4 GHz) will introduce standing wave issues and dramatically reduce efficiency. I have witnessed this many times on my SWR bridge when tuning my antennas. It is also why you will see coils on multi-band antennas. As for receiving, at lower frequencies (HF), there is an advantage to using a longer antenna to harness more RF, but not at microwave frequencies. Besides, strictly 802.11ac devices will not have antenna sized for the 2.4 GHz frequency band. Next to blocking, in this regards, 5.0 GHz is much better than 2.4 GHz according to the professor. It is away from the O-H frequency so water-based objects do not affect 5.0 GHz nearly as much as 2.4 GHz. As for 5.0 GHz scattering more, that is also an advantage, it allows MIMO to work that much better.

georgeou

My point is that lower range and more blocking is better because it allows for higher density deployments. I've seen a research paper that listed the attenuation for 5 GHz and 2.4 GHz going through various materials and the vast majority of materials block 5 GHz more. But this as a good thing for high density deployments because it allows for more spectrum reuse. If you really want to punch through a wall or reach out further without deploying more access points, you can deploy a higher gain antenna. There was a nice article on ArsTechnica on the massive 5 GHz WiFi deployment at the new 49erâs stadium being built in Santa Clara. Thereâs really no choice but to go super high density with intentionally low power small and shaped coverage cells if you want to offer high capacity to tens of thousands of people in a stadium. 2.4 GHz is just not going to cut it with only 3 unique 20 MHz channels and only 80 MHz overall. The people building the 49erâs stadium pointed out that by the time they launch in 2014, there will be more generations of iPhone and they will all support 5 GHz. Iâm not sure about 802.11ac but at least theyâll support 802.11n.

ok1dix

1 Like

RF signals are attenuated with square of distance NOT exponentially. I wonder if the other informations in the article are also so reliable.

Michael Kassner

I quoted from this source: "The radio signal gets attenuated exponentially while propagating. From above figure it is clear that keeping transmission distance (d) fixed, the higher frequency signal (f2) gets attenuated significantly than does the lower frequency (f1) signal. It is also observed that when the transmission distance is near, then the selection of frequency (microwave antenna of certain frequency) is not so important because there is not much difference(A1) between the attenuation occurred by higher frequency and lower frequency whereas it is very much important to choose the appropriate frequency (microwave antenna) when the transmission distance is far because there is a significant difference (A2) between the attenuation occurred due to higher and lower frequencies. One should choose the lower frequency microwave antenna to establish the link between the two stations located quite far away from each other." http://www.sanjayagurung.com/allfiles/documents/research_projects/AttenuationOfMicrowaveSignalAndItsImpactOnMobileCommunication.pdf This was my second source: "For example, a 2.4 GHz signal, such as that used by many IEEE devices, will attenuate by approximately 80 dB in the first 100 meters and then by another 6 dB in the second 100 meters. As you can see, the attenuation becomes much less in the second 100 meters than in the first, and this is due to logarithmic attenuation. The following formulas are used to calculate free space path loss in dB: LP = 36.6 + (20 log10(F)) + (20 log10(D))" http://faculty.ccri.edu/jbernardini/JB-Website/ETEK1500/1500Notes/CWNA-ed4-Chapter-2.pdf I have seen the logarithmic formula on several other sites. Maybe you can help me out here. Would this be a better statement: "Free-space propagation of an RF signal is attenuated logarithmically." As to whether that means exponentially or attenuated with the square of the distance, I can't say, that's why I left it to the experts. What is your opinion?

ok1dix

Well, I should have written it in more details. 1. The RF (especially microwave) signal attenuation is attenuated by a lot of factors, as already stated by others. So the practical result may be very different on various bands. 2. However, when talking about the attenuation by distance following applies: Free-space path loss is proportional to the square of the distance between the transmitter and receiver, and also proportional to the square of the frequency of the radio signal. http://en.wikipedia.org/wiki/Free-space_path_loss Don't be confused by logarithms in the equations. They are there just to express the attenuation in dB, but it does not mean that the dependence is logarithmic or even exponential.

Michael Kassner

First, thanks for explaining. I also have another question, but I am afraid to ask it. Because my math is well, you know. But, here goes: isn't squaring something exponential? I'm wondering if the paper I first sourced had a translation issue.

mhammett

Additional factors affect attenuation such as that frequency's susceptibility to different molecules in the air. For example, 60 GHz has far worse free space loss than 70\80\90 GHz. 60 Ghz is known as the oxygen absorption layer.

mhammett

1 Like

That is correct.

Michael Kassner

And if I remember right, 2.4 GHz is known for O-H (water) absorption layer.

thomas4442

I currently have a home network with AT&T as my ISP. I have 6mb speed. I tested the speed by bouncing a 30mb file off of a server in North Carolina, I'm in S.Ga. I consistently was >upload/download>5.9/5.2. The new modem/router is a 300mb. (WiFi). I have a TPlink wireless usb adapter (150mb) on my office PC in my room. Once I have established my ISP speed, I test the wireless streaming speed like this> Go to YouTube and watch a video (Netflix too), at the bottom of the screen is the video (data) progress bar. It's RED for what's been and being watched. It moves as the video is watched. Just in front of the DOT at the beginning of the RED line is the "Grey area". This tells you how much data is stored in the cache or buffer. If the "Grey area" is staying ahead of and increasing in distance from the DOT, then the wireless>stream>buffer is fine. It was ok at 150mb but not 54mb. 802.11n is better. As for distance, I live in an apartment on the second floor. When I switched to "N" my signal strength doubled outside of my apartment. I needed this as I do PC repair and networking by contract occasionally. Now I can pull up in my parking lot at 30/35 meters or 100ft., and log onto my network in my apartment to retrieve files I may need via laptop without getting out of my car. Switching to "N" made my download speeds on wifi go from good to better, and made access from a distance go from not possible or not worth it to possible. I could remote in also, but my daughter is in college and I can leave files in a personal shared folder for her to access when I'm not home. Just goes to the parking lot! P.S. I have 7 to 10 active wifi networks I can pick up various strengths. Occasionally the wifi signal slows. This is a recent issue since my switch to AT&T Uverse. I resolve the issue by changing channels in the router. It has a "best channel" feature that doesn't work well, haven't figured out why yet!

Michael Kassner

I assume you are using 2.4 GHz. The coverage you are getting now is likely not possible with 802.11ac due to the 5.0 GHz requirement.

said.fox

The article could be regarded very good introduction about the new protocol. However, what about the covering range area that new protocol may offer to me as a home end user. Nowadays, in our houses we swim over a lake of wifi signals of our neighbours, interference and shortage of coverage inside the house may be an important concern. What I need to know, what's the max. distance, horizontally and vertically (up stares, down stares) that my ac wifi network reach?

Michael Kassner

1 Like

That kind of information is not available yet. There really isn't that much equipment out there, and I know of no computers that have built-in 802.11ac clients. Also, 802.11ac will be more sensitive to individual physical surroundings and spurious RF signals. Are you able to use Wi-Fi currently?

martinw

1 Like

Doesn't the new macbook air has the 802.11AC client built-in?

Michael Kassner

I prefaced it with that I know of, and what I now know has changed. Do you have one? How does it compare?

stasys.lukaitis

Mimo has another unforeseen effect - that is called a microcellular effect. The transmission radii from a pre-"n" technology was even and predictable. The transmission radii for mimo devices is unpredictable and very jagged because of signal bouncing/absorption/magnification. Transmission density patterns resemble a mosaic and beamforming doesn't address it. Sticky client phenomenon still exists causing trauma when moving from one AP to another. "N" and post-"n" technologies really work well when there is a high density of APs with each using low(er) power output and configured in greenfield mode.

Michael Kassner

1 Like

When researchers first publishing papers about 802.11n in 2008, I ran an extensive series on MIMO and beam-forming if you are interested: http://www.techrepublic.com/blog/wireless/wi-fi-101-multipath-environments-and-how-they-affect-wi-fi-propagation/143 http://www.techrepublic.com/blog/wireless/how-to-make-the-best-of-80211-multipath-environments/147 http://www.techrepublic.com/blog/wireless/80211n-mimo-and-multipath-environments/156 http://www.techrepublic.com/blog/networking/80211n-mimo-really-needs-smart-antennas/505 The marriage of smart antennas and MIMO make 802.11n the great protocol it is.

dennis.cb

10 Like

The comment regarding the Internet being the bottleneck is somewhat misplaced.. That's like giving the impression there isn't much use for Gigabit Ethernet, because the internet is still a bottleneck. Many people, including myself, transfer/stream large files and storage around to PCs/consoles/external HDDs on our private home networks. Right now, even with 802.11n, it is still painfully slow when compared directly to wired Gigabit Ethernet. Assuming you have a fairly clean/quiet radio spectrum environment where you are, this could provide pretty significant gains for short-range wireless connectivity.

Michael Kassner

1 Like

I mentioned that in the article, although not clearly enough. I also pointed it out in an earlier response to a member comment. Just be careful about the coverage area, and remember that 5.0 GHz RF is considerably more touchy than 2.4 GHz -- more multi-path reflections and absorption by water-bearing materials.

mhammett

Multipath is a requirement for the high chain counts in today's MIMO radios.

Michael Kassner

But 5.0 GHz is more active a frequency thus more reflectivity as I understand. Thus the potential for out of phase reflections to cancel each other out increases.

Smart_Neuron

Hi there. If you are running your own internal network and your components are matched, 802.11ac is a very nice choice for those who *need* to upgrade. Otherwise, 802.11 is quite sufficient. The external internet is the real problem, which causes a terrible bottleneck in throughput. The technology is there to overcome it - but will your ISP provide it yet at a reasonable cost? I say no! Read this link... http://news.cnet.com/8301-1023_3-57589353-93/is-cable-holding-back-superfast-broadband-adoption-on-purpose/?tag=nl.e703&s_cid=e703&ttag=e703&ftag= The industry as a whole needs to step up it's efforts to produce more bandwidth.

JCitizen

so yeah - I'm very interested in this article; which was exceptionally clear and well written! Thanks again for another blockbuster Michael! :) Dang! Just as I had thought I found another good UTM appliance! I might as well wait now! I want that fast client side speed! :O

Michael Kassner

What kind of deal did you pull off? What are you doing that you need gig Wi-Fi? You have me curious now.

JCitizen

it is an area wide association. So since we are not profit oriented we went fiber years ago - in fact Sprint was renting fiber backbone from us many many years ago to cross the Midwest bandwidth barrier. We now have fiber up to every farmer in the region. I look at places in the US that don't have that already and kinda feel sorry for them for being so bakards! HA! :D Two of the larger population centers have converted to gigabyte, and we are next on the list; so we should have it in a year or two. They were going to go light all the way to the end user network card, but with the revolution in mobile and the PCs doing so badly, they decided to keep the copper in the final loop for now. As far as needing it - not really - but it does make video streaming on Netflix a snap - since it is basic service, I certainly am not going to reject it; at least that is how I understood it from a local newspaper article. Even if they charged a few bucks more, I would probably pony up the cash, because I do a lot of remote RDP, and the bandwidth makes life more bearable. There is actually a lot of competition here with Verizon and Wheatlands wifi, so they really don't have a choice but to offer it as basic service to get folks to come back to them.