Trucker Tech Podcast Transcript: Episode 6, Part 3

And here, today, is the final installment in the transcript for the Trucker Tech Podcast: Episode 6; the Commentary. I get off on all kinds of tangents and probably sound a little bit (or, maybe, a whole lot) like I'm trying to convince you, the listeners, that I'm a whole lot smarter than you. Well, that wasn't my intention, I got off on tangents 'cause I lack the ability to focus and, as far as the "whole lot smarter than you" attitude goes, I was just trying to give my arguments some credibility.

If there's one thing the years have taught me it's that the more I learn, the more I realize just how little I really know. Anyway, I wandered so far afield in this commentary that I had to break it into two parts, the second of which will be included in Episode 7; and I promise, I'll focus and lose the attitude.

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Commentary: Truck Stop Wi-Fi Facts

Awhile back I authored a post at Life on the Road discussing the fact that Flying J is attempting to create a single Wi-Fi service - available at all the major truck stops. Whether that ever happens or not is anybody's guess and I'm not holding my breath. But judging by the comments related to that post, as well as some of the emails I got, it became glaringly obvious that a tremendous amount of confusion and misinformation regarding Wi-Fi is floating around out there.

I guess that shouldn't surprise me because there are certain truck stop Wi-Fi related issues about which I sometimes become confused, as well - and I wrote the book on it - literally.

Now, before I get started here, let me make it perfectly clear that I'm biased toward Wi-Fi. I have my own reasons for this and if you're a Cellular aficionado then hear this clearly. That's fine with me; if it works for you and meets your needs I couldn't be happier. I've used, and still use, cellular; and I'd be willing to bet my experience with it, in all its permutations, far exceeds that of most users.

My dad helped design and build some of the original microwave stations for Southern Pacific Communications Company back in the sixties and seventies; you're probably more familiar with SPCC as it exists under its current moniker: Sprint. Granted, microwave communication as implemented by my dad and his co-workers wasn't exactly cellular but it was certainly the forerunner to it.

And during the fifteen or twenty years of his involvement with the microwave communication project I was privy to tons of wireless communication information of both a practical and technological sort.

Not that I was entirely able to understand all of it, mind you, my dad had a tendency to communicate using mathematical equations in much the same way that most of the rest of us use sentences. Still, some of it soaked in so I don't think I could be accused of harboring a preference for Wi-Fi simply because I lack an understanding of cellular.

Enough of that rant, I see my purpose, here and on the web, not as an advisor but more of a provider of information. I figure everyone is capable of absorbing information and, after weighing the facts, determining the course of action that best suits their situation.

To that end, in today's commentary I'm going to provide you with a few facts related to truck stop Wi-Fi. Not in an effort to convince you that Wi-Fi is better than cellular 'cause that's what I use and you're an idiot if you don't think that everything I do is what you should do. Nope, this is information for the sake of information. The more you know, the better your decisions.

The fact is, I don't think either one is better than the other. They're both tools; different tools.

First, the biggest complaint I hear is that truck stop Wi-Fi doesn't reach the back row. I've even heard and read statements to the effect that truck stops should boost the signal because you're paying a lot of money for the service; a conclusion drawn from the well of ignorance if I ever did hear one.

The difficulties of reaching the back row of a truck stop with a Wi-Fi signal do, indeed, have something to do with power but you should know that all Wi-Fi equipment, because it broadcasts a radio signal, is regulated by the FCC. Further, regulations limit the amount of radiated transmit power, from a commercial hotspot, to 36db; the equivalent of 4 Watts.

But wait, that's not 4 Watts of transmit power, that's RADIATED transmit power, which takes antenna gain into account. Therefore, if the hotspot incorporates an antenna whose gain is 6dbi, which is common, then the transmit power output, or TPO, must be reduced to 30dbm, or 1 Watt. Okay, I can hear your head whirling with the math; you've already divided 36 by 4 and you're figuring that if 36db is 4 Watts then 9db is equal to 1Watt so…30 divided by 9, carry the 3…should be 3 and 1/3 Watts.

Well, you figured wrong. Decibels aren't measured in a linear fashion, they're measured logarithmically. If you'd ever sat and had coffee with my dad, you'd know that. You might've even kept the napkin on which he wrote the equation. I know I wish I had. Simply put, a decibel is a relative measurement of intensity that's expressed on an absolute scale by incorporating an arbitrary constant. You can measure all kinds of things in which intensity can vary, light, sound, power, all kinds of things.

Here's a lesson for us all. The relativity of one thing to another can only be measured against a constant. Man I'm really getting off on tangents here but that's a worthwhile thought. I'm not going to go to take the time to discuss it here but you think about that statement, the relativity of one thing to another can only be measured against a constant, and if you leave a comment or send me an email I'll be happy to discuss it with you. It pertains to truth, justice and the American way. Think about it.

Anyway, back to radio related stuff. For transmit power, decibels are measured relative to 1 milliwatt, expressed as dbm.,  For an antenna, decibels are measured relative to an ideal, and hypothetic, isotropic antenna, expressed as dbi. Every 3db increase, either dbi or dbm, is the equivalent to doubling the relative intensity. Conversely, every 3db decrease is the rough equivalent of halving the power. Therefore, 30db is the equivalent of 1 Watt, 33db is the equivalent of 2 Watts and, 2 times 2 equals, 36db is the equivalent of 4 Watts.

Okay, that's more than anyone really wants to know about measuring decibels and way off my point so let's see if I can get back to it; focus has never been my long suit. Oh yeah, the reason it's so hard to get a Wi-Fi signal in the back row of a truck stop. Okay, by now you can probably see that a hotspot is probably going to transmit their signal using around 1 Watt of power and they're going to receive using about a 6dbi antenna. This is done in an effort to balance both transmit and receive capabilities.

But that's only half the equation. Flying J, for example, tried using amplifiers on their radios but they found the amplifiers were increasing the noise as much as the signal so they scrapped that idea and began to work on other solutions. In the course of time they found that the quality of the WiFi device on the client side, that's your laptop if you were wondering, was a key factor.

No matter how strong the truck stop Wi-Fi signal might be; a cheap and weak internal or PCMCIA WiFi card just wasn't strong enough to communicate BACK to the access point. Remember, it's a two way street and both the access point and your laptop must transmit and receive signals from each other.

That's why, in "Over the Road Wireless for Dummies", I recommended using the high transmit power SMC2532W-B PC card coupled with a high-gain antenna. You, the Wi-Fi user, need to balance antenna gain and transmit power, just like the hotspot. Adding an antenna without increasing your TPO or increasing your TPO without adding a high-gain antenna won't get the job done.

There are other alternatives available and, in episode 5, I highlighted a few of them including the solution currently advocated by Flying J. But there's another issue, one not so easily dealt with, that also wreaks havoc with Wi-Fi radio signals.

You may or may not be aware of the fact that 802.11b, g and n radio signals operate in the 2.4GHz band. That's an extremely high frequency and high frequency signals are far more susceptible to interference then are those of low frequency. Again, if you'd spent time sipping coffee with my dad, this is something you would've learned. Over the course of several napkins, he might've even written out the equation illustrating the point. My dad always required lots of napkins with his coffee - but not because he spilled stuff.

The only means available to truckers trying to maintain a Wi-Fi signal in the back row of a busy truck stop, filled with tons of interference generating trailers, moving or otherwise, is to get your antenna up in the air as high as possible. Flying J mounts their antennas on the roof of their facilities but, if yours is nestled in a cubbyhole deep in your cab, you might experience interference related problems.

The solution to the problem is to get your antenna as high as possible. You might also decide to use a directional rather than an omni-directional antenna. A directional antenna whose gain is equal to that of an omni-directional antenna will be far more effective because the energy is focused. Kind of like the difference between a lamp and a flashlight of equal power.

I've babbled on long enough about this subject for one episode so I'm going to cut it short here and I'll continue this effort of enlightenment in the next episode where I'll take a quick look at another common Wi-Fi related misconception, summarize the whole thing, and provide you with the reasoning behind my decision to use Wi-Fi as my primary means of connecting with a cellular back-up rather than the other way around.

No, not in an attempt to convince you to do the same; just so you know where I'm coming from.

I don't, obviously, go into a whole bunch of detail in a short podcast but a lot of the information I provide here, including a few finer points, are included within the text of Over the Road Wireless for Dummies. Even if you think you're a well informed individual, it wouldn't hurt to pick up a copy and read it. There's some dated stuff in there but it'll lead you in the right direction and, as Buckminster Fuller once said: "you can never learn less."

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Closing:

That's it for this episode. And, once again, I thank you for joining me. Don't forget to visit the Trucker Tech blog, Life on the Road, and theCyberTruckStop.com. Look for those web addresses in the Quick Links section of the show notes. As always, your comment and criticism is welcome. You can post them at Life on the Road or, if you prefer, visit theCyberTruckStop.com where, on the comment page, you'll find a few methods by which you can contact me more directly. You can also try to Skype me; I'm Cybertrucker114.

In a few days I'll post a transcript of this podcast on the Trucker Tech blog and, should you choose, you can comment there, as well.

Till next time - take care!!