802.11ac Speeds

Faster, faster faster!!! That’s what we all want right? Faster cars, faster computers, faster Wireless?


Well, let’s put the brakes on that for a minute and talk about this.

Let’s talk about what happens when we go “faster” and how we achieve it. Let’s start with Channel Bonding. Wireless uses a 20MHz wide channel to pass traffic, let’s think of this like a 1″ hose. In 802.11n with 5GHz channel bonding, we can now take that single 1″ hose and join it with a second 1″ hose, and basically have a 2″ hose that can spray more data. Sounds great right?!

The other way we get faster is modulation. Modulation let’s you say more in the same amount of space.. Anyone remember The Micro Machines ManJohn Moschitta could say more in one minute than you could. Or if you prefer this analogy, the smaller you can write on a sheet of paper the more information you can get on it. 802.11ac allows for up to 256-QAM Modulation and we can take that bonding and go 20, 40, 60, even 80MHz wide!! ZOMG the speeds, the speeds!! *STOP*


Now we need to think a little bit about how this is going to affect the wireless network. So to start a little refresher. In the U.S. we have 3 non overlapping channels in the 2.4GHz spectrum 1/6/11. Now we all know that the 2.4GHz is “dirty”, lots of things can (and do) interfere with it. We also know that with the density that is needed to support BYOD/BYOT that even when the power is turned to it’s lowest setting there are issues with CCI (co-channel interference) and ACI (adjacent channel interference).

In the 5GHz spectrum, we have more channels (9-12 depending on the installation), and a “cleaner” spectrum. For the purposes of this post, we are going to assume we have 12 channels.


40MHz wide, if we go with 12 channels, that means we can have 6 channels to use. In most environments that should be fine, really dense deployments like Stadiums aside.

80MHz wide, again assuming 12 channels, we have only 3 channels that we can use. This puts us right back to one of the issues with 2.4GHz, we don’t have enough channels. So let’s hope you’re not doing this.



In the above infogram, you can see the max connected rate and throughput for a an 802.11ac client with 1/2/3SS. Remember this is “theoretical” and perfect world.

802.11ac wave 2 allows for up to 4 SS, and channel bonding of 80-80 or 160MHz wide. If we have issues going 80MHz wide, why would you want to go even wider and have only 1 usable channel? And “usable” it may not be depending on what your neighbors wireless is doing. Adding another Tx/Rx pair to a device is going to, probably, make it bigger. We all want to carry aroudn 17″ laptops and phablets right? That’s why what I’m really waiting for is MU-MIMO.


So for all the spiffy new speeds we can get, to achieve those “theoretical maximums” we have to sacrifice our spectrum, which we shouldn’t do. Channel reuse becomes a pain again, even if you are using some automagic channel/power settings.


Granted, this is all IMHO, take it or leave it.

Emotionally Invested

So recently, I’ve been hearing from a lot of different sources that “We need to keep emotion out of it”, whilst talking about business. And for the most part I was agreeing with this, and then I really started to think about it.

Can you keep emotion out of it? Really think about this for a while, then come back. I *love* what I do, love is an emotion right? I *hate* when I fail, again isn’t hate an emotion? I get *scared* when I think I’ve missed something, especially when there is a deal hinging on if I missed this or not. I think you see my point.

You absolutely can NOT keep emotion out of it. With out emotion you don’t have *passion*. With out *passion*, you should be looking for another job. I can’t ever see myself just going about my day to day, being ambivalent as to whether or not I win, lose, fail, succeed, get a raise, get fired, get a promotion etc. etc. And I sincerely *hope* that if I ever do feel that way, I’ll have already found a new job.

Cisco Live 2013 aka Geeks in the Swamp


So being my first blog post, cause you know I heard somewhere this was the thing to do between tweets..thanks Amy (@CommsNinja) decided I’d revisit why I didn’t blog in the past, and why I’m going to be doing it in the future. So why is this titled “Cisco Live 2013 aka Geeks in the Swamp”? Well the picture above has a lot of tweeps and bloggers that finally made me rethink, and it’s where I was last week.

The Why I Didn’t

Basically, I could call it laziness and that would be a part of it, but not the whole truth. The biggest reason I didn’t blog was I couldn’t really find anything that “I” found interesting enough to blog about.

Let’s be honest, I work with wireless and oh yes it is definitely an interesting technology. But after ~5 years in TAC there wasn’t a whole lot I haven’t seen, broken, fixed, played with or snarked about. It was multiple conversation at Cisco Live this year, Tom (@networkingnerd) Andrew (@revolutionwifi) Colin (@colinmcnamara) Amy A.(@amyengineer), and way too many others to realistically list here, that made me realize it’s not what “I” find interesting, it’s what I can share to help others grow!! *facepalm* It really is that simple

The Why I Will

There are two main reasons why I decided I should kick off a blog, one is to share knowledge around wireless/BYOD which is kind of a passion of mine, and to help me document my learning of scripting (Python, Puppet etc).

Cisco Live 2013

Let’s call it what it is, Geek-vana! A bunch of really really smart people all getting together to share knowledge, see old and new friends, and let our Geek flags fly.

In years past (2006/2007/2008) I was stuck in TSC (Technical Solutions Center), and last year sitting in session after session. wHile I did learn a good bit during the sessions, this year I took a different tact. This year, it was all about the social aspects of the conference. I spent a vast majority of my time in the Social Media Hub. Chatting with new friends I met on twitter over the year, old friends I met at other events, and listening. Yes, I listened, amazing right!? Funny thing is when I did I heard the same thing. Blog, Bacon, Blog, Cloud, SDN, Blog, Unicorn and Bacon.

But being in the Hub also allowed me to be agile of calendar. I could go to the side meetings and briefings, there were a few where I thought I’d just listen and not have anything to share…turns out that I was incorrect about that.

To sum up, I learned a lot during the breakouts, where the network is going, why Engineers need to learn some scripting, what cloud can do for me, how many others enjoy bacon (really who doesn’t!), and that I should blog.

I call it a net win for the week.

So the long and short..pay attention kiddies.