Nigel Bowden talks about his podcast series, “Wi-Fi for Beginners” that he created to help those just getting started in Wi-Fi. The series is already several years old, but is still very helpful if you need to get a crash course in 802.11 technologies.
UK Based Mobility/Wi-Fi Consultant - CWNE #135
Nigel is Wi-Fi Network Architect, with 20+ years of proven experience in designing, delivering & supporting LAN & Wi-Fi networks for Government Agencies, Education, Healthcare & Financial Clients –improving coverage, capacity & enabling flexible working.
He implement best practice design methodologies to ensure successful business outcomes and realisation of ROI, and creates high quality, technical documentation, including high and low level designs for all phases of network design & operation lifecycle. He articulate technical concepts to audiences of varying technical capabilities to allow stakeholders to understand and make informed business decisions. Furthermore, He engage with cross-functional teams to drive definition of requirements and ensure final solutions meet business requirements. Also, he mentor colleagues & other technical teams to develop their technical capabilities and share knowledge.
Check his website: http://wififorbeginners.com/
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Wireless LAN professionals podcast episode two oh one wireless LAN professionals is a place to educate, inform, encourage and entertain those involved in wireless LANs, this wireless LAN professionals podcast as an audio manifestation of these goals. Our host is a wireless land veteran consultant, designer and teacher Keith Parsons, and now the podcast for wireless LAN professionals by wireless LAN professionals.
Today I have with me Nigel Nigel Bowdon, right? That's correct. And you're in the UK. Nice sunny day there.
You've been out running today. Now a little bit of a break today. I've been out most days, but some a little bit of bright. Don't don't overdo it. Not at my age anyway.
Overdo it. Yeah. You're a youngster. I thought I'd get you on the podcast today and talk about your podcast slash training side and how you put it in the category.
Your Wi-Fi for beginners decided to put it together as a sort of limited series podcast really delivered over an RSS feed and it's on iTunes, that sort of thing. But I thought if I just do a limited series podcast, like you say, so it's like a sort of mini training course where you just to get people going on the basics of of Wi-Fi theory.
So why did you use the podcast as the delivery mechanism rather than some other training delivery service?
It's quite interesting, really, because this is it's obviously been a few years since I since I've put this together. But I was going through a stage of listening to lots of podcasts when I was doing lots of traveling.
So I was driving in the car, train journeys, things like that. And I'm funny enough, I was sort of consuming a lot of technical content. And one of your one of your early podcasts was sort of one of my favorites, really. I remember hearing you appearing not I think was on the Cliff Ravenscroft podcast. He was the podcast and man. And you appeared there and you were doing all these putting out all this great content. And I was consuming, you know, what is this technical information really enjoying it. And I thought, wow, agree. It's what I like to do that myself one day. And then when I had this idea of trying to put the podcast or some sort of training package together, I thought podcasting would be a great way for me to be able to deliver it in a fairly easy way. But also people gout's consumer on the move. If they're just driving to work or maybe on a flight or, you know, taking their train journey, it's just a nice way to sit there, just listen some information and then absorb it in a fairly sort of easy way that that's enough to invest too much time reading books, things like that.
As the podcast or of course, develop, what kind of hardware do you need to put together for your first podcast recording?
It was all it was all very low tech, to be honest. I just bought myself and my USP Mike and experimented with learning how to use the audacity to do some recording and and sort of struggled through understanding how to edit audio and sort of manage to pull it together.
And then you have to figure out how to put it Willington, RSS feed, etc. and better Web sites around. It was a bit of a learning curve, but it was very interesting and I really enjoyed doing it, to be honest.
Everyone can hit this by going to Wi-Fi for beginners dot com beginners with the S r Wi-Fi for beginners dot com. We'll put a link to that in the show notes. You can also find it on iTunes and you have a separate RSS link as well. Yep. Yeah.
And all of those you can find on that website, you can subscribe by going to the ice from the Ice Tunes podcast application and also like safe tuning Staun. Actually put the episodes on to YouTube as well.
And as some people like to listen to audio on YouTube, so I've transferred them there as well. So if you wanna subscribe to the play list, if you search for Wi-Fi, Nigel and YouTube, you can subscribe to play list and get all the episodes.
If you see me that way, then you do have matching slide decks to go with them for each of the modules.
So I've decided to do was just sort of break the content down into a number of modules to try and give it a little bit of structure. The main aim of doing it was to try and give people an audio only set of content that they could consume on the move.
But there was still there are still a few topics which are quite difficult to explain. Audio only. So out of reach of the modules that I broke down into, I created a set of slides as well and I just sort of PDAF slides.
So the idea was you could actually go to my website, download the slides, and then when you were sort of sitting on the train or whatever, you can be listening and if needs be, maybe just fira the slide deck and have a look at one or two diagrams that IBM that I talked about, you know, during the actual podcasts.
What was the chunks? You have different, what, 21 or something different?
I tried to sort of break it down into the sort of main areas that are from people who were just starting out with Wi-Fi networking, but having a few problems with them.
I mean, the background to this was I've met a lot of people in my work who were really good network engineers or, you know, there may be maintained, you know, network administrator maintaining big networks. And they've got a lot of expertize and routines. Watching a security, but they were having to try and, you know, carve a little bit of a path into Wi-Fi as well. And they were maybe struggling to get a grip of it. Maybe a tender vendor cause something like that and understand how to drive the equipment for a specific vendor. You know, the wireless equipment that they would really not get any of the basic RF type theory understand the to Alem standard. And so I really wanted to get all of those areas subject to areas where people weren't getting that depth of detail and give them a nice, gentle introduction so that they could then go away and maybe start looking at things like the CWNP books, the CWNA study guide, things like that, which, you know, out of the gate is quite daunting. I mean, it's it's a big, thick boxcar, lots of really heavy theory in there. Fantastic reference resource. But for began a maybe a little bit overwhelming. So I basically broke it down to six modules. So I basically started off in the first one just looking at, you know, what do we mean by a Wi-Fi network, talking about things like a 82 to eleven in the various components in a wireless network.
Then the second module takes a look at, you know, the RF characteristics that we need to be aware of. Things like, you know, what do we mean by RF signals? Ah, if spectrum, you know, concepts such as coverage modulation moved on to a third module where we started to look at the actual some of the main components for Wi-Fi network. So in module three, we look to access points and talking about what they look like, how you would install them, you know what they actually do in the Wi-Fi network. Then in module four, moved on to a little bit more in depth, talking about various our principles. So we've revisited RF, started looking at things like what we mean by half duplex transmissions and CSM, A.S.A., things like that. Then in the fifth module moved on again to another major component in a wireless network, which is Wi-Fi clients, and started to have a look at, you know, what the component parts were, you know, talking about the fact they've got a radios in there and antennas, things like this, and started to dove even deeper into the ATO eleven standard. And then in module six started look at the wireless infrastructure components, things like wireless controllers and talking about things like the management control and data plane. So trying to give us sort of fairly rounded but not too detailed or overwhelming approach or coverage of the topics that you'd need to know to get Goan in Wi-Fi network.
Well, I did notice that of the 19 separate recordings that are all available on Empey three as well, if you wanted just to download them. There's six of the 19. A third of it is all about Wi-Fi clients. Why that? Why the focus on clients? Just I mean, just a general question that we'll come back to this specific.
Once you start diving into clients, I needed to actually introduce a few more details around eight, around eight to 11 itself.
So. So when you start talking about the capabilities, you then also have to talk about things like eleven nine, eleven K and the more deep, you know, more detail of the capabilities a client may have. It's just it's a big topic. I mean, that's the area really that seems to cause the most problems when you're trying to design a wireless network because of the, you know, the various idiosyncrasies of derman different capabilities that they've got. So it was just a big topic and they did need a lot of attention.
I totally agree. I mean, if you just think of the just by count, if you if you're running a really dense network with lots of APIs, you might have a 10 client to one AP ratio. Sometimes you're up to the 20 or 30 clients to AP ratio. So just by count, we have lots more clients to deal with than we do APIs and APIs are usually if you're a Cisco shop, they're all Cisco. Whereas clients are all over the map. So I was supporting it. It's a good idea to have that.
Well, you did these back in the end of 2015 and in spring of 2016. How much has changed since then?
There's been some developments for sure. Obviously, we've got eleven acts and we've got the whole business, about six gig being on the horizon. So things have certainly moved on.
But looking back up the slide decks, you know, in anticipation of doing this podcast, I was quite surprised, really.
You know, a lot of the base material, the foundations that you need to build on, it never really changes, you know, the RF and all and the eight to eleven standard.
You know, the vast majority of the principles and theory that you need has changed very little. It is incremental additions since then. But yeah, certainly six gig is a is a big one that's going to be missing from there. And that's going to be something that's going to become more important over the next year or two as that becomes approved for use in different countries.
I agree with you. The fundamentals, the things that the RF pieces, how antennas work and basically how most dotel haven't worked hasn't changed. Really, in two decades, the pieces are still there. I was just teaching a class the other day and nearly 20 years ago I made the first graphic that had the green diamond that I talk about on hand. It was a page that had where a client has to associate you in. And we wanted to show that it was a decision. So decision in a flow chart as a diamond. And since the graphic artist already used a bunch of other colors, we decided to paint it green. And the picture even has a graphic of a laptop with a piece DMCA card plugged in and tells you how old it was. And I was using that the other day and somebody asked and said, why is your laptop have that little thing sticking out? And they had never even seen me there that young. There were probably nine born then when they saw that, I explained it to Nicole. Really? You had to stick stuff in. But that concept of a client making the decision which A-P to join. Yeah, still same thing. So even though this might be five years old, it's still the same way this stuff works today. And we don't even have, you know, six gig clients or so a piece today. So you still start some time before you have to update.
Yeah, yeah. I definitely have to give that some thought.
So in any thought of updating it to add we probably had Acey since then, at least wave to that.
We were, we were in the midst of eleven acey back then, so I think I would definitely like to revisit some parts of it and refresh the content and especially our, you know, people must be wondering, well what about 11 X, how does that change things. What's that gonna look like in the future.
Right now my my my question is, does it work. The people I know can't even even even we tried. We just had a deep dove, a five hour deep dove at WLPC in February.
And Peter also gave a presentation in Prague as well. Peter McKenzie, where we're trying to take it or heaven A.S.A.P. and actually prove that it's doing the things that it's supposed to do and can't get it to work using the the there's not like a lot of clients anyway, but we found clients that could work, that could connect, but they didn't use the AICS functions. Yeah. So there's a lot of hype still, I think.
Yeah. Yeah. I must admit the that there's some great sounding features in there, but the proof will be in the pudding really over time.
Interestingly, I attended one of Devins Wallace suggested courses recently and he's got these various principles of design that he currently adopts. And one of them is to turn off the eleven IEX features because here they are still so variable, shall we say.
Stability is always a good thing when you're doing testing. So I don't know where that's going to be. I put out a challenge a little while ago to my friends who work for vendors and said, hey, can you show me BSF coloring, working? I don't even care if it's in a lab. Can you just show that it works and no one's come back with a yes on that one yet.
So there's some features I think that are in a X that are the complexity over the last two decades is just got more and more and more complex. There's some pretty fancy things going on. But can we actually get them to work?
Yeah, we've been interested to see for Weft FDM A actually delivers that design very promising, especially in talking about real time clients, you know, voice type clients. If that if that could deliver, that could be very interesting.
I'm not because they don't need very much at all. They just need to be consistent. You also did a little test. It's actually one of my favorite things I've done a long time. And you did a very precise in taking a client and moving it mere inches to see what the difference are. Can you tell us about that little experiment you set up?
Yeah, I did a blog post about it. And, um, basically I got I think this is just a Samsung S7 phone, the phone that I'm using at the moment and set a test access point in my house.
I've got line of sight about five meters away. And I set up this phone and I put it on a little turntable.
And it was I think it was propped up at about 45 degree angle. I put the clients on this little turntable on the table and and took our Souci measurements. And what I did, I actually rotated it through 360 degrees in the horizontal plane and every 45 degrees took the ah soci measurement. It was well, it was amazing really just turning the phone through a few degrees and altering it's, you know, its position or its orientation to the access points had incredible impacts on the other side. I was literally you could turn it in some positions through 45 degrees and and get maybe a 10 debri loss.
It was it was incredible.
I would never have never believed that you could have such it's such a, you know, huge variation from a tiny movement in the client itself. I've always suspected it. I mean, I think people like yourself as a. I've always said, you know, you only have to move the client a few inches when you're taking water loss readings and things like that, and you can see quite huge variations. So you need to average these things out. But to have it in a static position and just rotate it, it was just is an incredible experiment.
Well, either in the show notes as well, because it's actually really good blog post. And I think people need to do that experiment on their own with their own gear.
And then they'll say, oh, wow, it actually did. It's the six inch square challenge.
That's the one. Yeah. Because I basically drew out of a six inch square on the table and moved the client to the four points, the four north, east, north, west, southeast, southwest points of the square. And even just move it through six inches an undoing. The orientation just got huge variation in results, which is which is amazing when you consider the implication for doing the Wi-Fi design.
When we're walking around and just getting there, measuring beacon measurements with a sidekick or whatever and trying to do a a rough offset, you know, the variations the actual clients are gonna experience is is immense and you need to factor that in.
And then there's the variation within clients. I was stuck in honor at super rainy day in Jakarta once over a weekend. Had nothing to do. So I and I had a bunch of I was teaching class, so I had a whole bunch of nick three hundreds. The eighty four, ninety four from Broxson. So I thought, well today's a good day. Nothing else to do. Let me test them. So I had a seven port USB hub with me, so I thought I'll test all seven at the same time. So I put an AP like you did five meters away, plugged them all in, and because I was using alcohol, I could control them to listen on one channel only by turning off all the other channels. They didn't try to change channels. They would just sit there and every tenth of a second they would grab another another piece of data and then I could plot the data out. It's very precise.
While doing that, I the first time I had them all in the hub at the same time, they were wildly different. And then I thought, oh, wow, maybe it is because of the position in the hub, the hub, maybe they're a centimeter apart, maybe a little more than that. Yeah, maybe that would matter. So then I rotated them from position one, position seven, and then backwards left the hub at the same place, actually ended up taping it to the desk so I wouldn't move and then found I got the opposite results. So it was actually the devices that were different, not specifically position, but to even put position out of it. I only tested one at a time in one slot. Now taped down. So there is no movement. And then tested 15 next. And what I found was a wide variation, like the highest was probably a seven or eight DB differential. Same neck, same orientation, same physical location, same AP. I was just swapping out next. So even within the same brand, same type, we have a variation. And then you add to that your sixteen's challenge and you now have some pretty wild, crazy answers and they're worthless and designed. So they all work. It doesn't bear thinking about here. Yeah. How do you design for that. Not. It's it's part art. Part science. Right. And then we go out and we try to fix it all after the fact. You wanna give us some places where people can go to if they wanted to listen in. And, you know, there's some spare time during this Cauvin crisis thing to go back through your your Wi-Fi for beginners.
Yeah, yeah. If you go to Wi-Fi for beginners dot com, you can also go to my my own blog, which is just Wi-Fi. Nigel Dot Coleman. There's a link there too to the Web site. And as I say, you could get on to YouTube as well.
Now if you do search for Wi-Fi to begin, this is a good chance it'll come up in the search listings there as well. So few places you can get hold of it.
And also the I tunes podcast up, you should be able to get it in any new things that we should be looking forward to on your upcoming blogs. What's the thing you're just thinking of? Maybe I should do this next.
I am very heavily into the w LAN pie at the moment, as you may know, and I never sort of tire of playing with and I'm I'm looking at any been by Devins recent classes of using remote probes or using that to be LAN PIs, remote probes, things like wind fly and Wi-Fi Explorer.
And I'm quite interested in and playing around with remote sort of VPN access for that so you can get through firewalls and things like that. I've been looking at a few packages there, so when I when I went off, sort of got all the details around that I'm propaganda to blog on that. And also Peter McKenzie's got me interested in a two to 15 dot four. He did a talk at WLPC in Prague and he was talking about VLA. And I'm quite interested in Bailey at the moment. That is going to be a lot of interest in location. Lacking solutions. Potentially. And so I want to know a little bit more about that same problem, a little bit of a play with packet analysis on. Maybe do some blogging on that potentially.
That would be good. Oh, by the way, there's Adrian's wife for a pro. Also can access a. It's eleven. Fifteen. Little neck. Yes. Yes. Not a chance to play with that. I shipped a couple over to Nick Turner. So you want to pick one up. You might want to hit Nick for a little bit and see if you can get one those to play with, because it's just a different way of getting the same data. OK, it's the same one that Peter used at Prague last year. OK, excellent. Nigel, thanks for taking your time to share your expertize with us. And glad to get out there and get more people in, you know, trying out your Wi-Fi for beginners and then bring them along. OK. Thanks so much for having me. I've really enjoyed it. Thanks.
Thank you for joining us for another episode of the wireless LAN professionals podcast. The podcast for wireless LAN professionals by wireless LAN professionals. Be sure to follow us on Twitter at Wireless Landreaux for all the latest news and updates and also connect directly with Keith on Twitter at Keith R. Parsons.
Head over to w w w w LAN pro's dot com for this episode show notes as well as the latest in all things Wi-Fi.
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