One of my closest friends was recently diagnosed with leukemia. The inpatient portion of his chemotherapy regimen was short enough that provisions for cable-based network access would be silly, but long enough that any serious engineer would suffer from Internet withdrawl.

When I visited Nick in the hospital, I was quite surprised to see him working away on his laptop, using ssh to help troubleshoot a client’s network problem. Although the hospital where he was being treated did not provide Internet access to patients, his room in the oncology ward was across the street from a university with an 802.11 network. Wireless networks are extremely flexible and excel at providing transient access to an amorphous user population. After being admitted to the hospital, he spoke with the IT director at the university, and arranged for permission to access the university’s 802.11 network during treatment. No new infrastructure was required to support him, just a straightforward configuration of the university network.

To shoot across the street, Nick used a old Lucent Hermes-based card with the 10 dBi external antenna shown in the picture below. The connection was fairly reliable, but it did drop out occasionally. I suspect that the problem was due to the use of multiple pigtail connector conversions between the card and the antenna. The Lucent card uses an MC Card connector, which was converted to an SMA connector, which was then converted to a N connector before reaching the antenna. Each junction causes some reflection and reduces the antenna’s effective gain, though I have no idea how to quantify the reduction.

Quite happily, though, there was no need to make the connection any more reliable. I was more than willing provide antenna parts to improve the quality of the connection, but Nick’s condition improved so much that inpatient treatment was no longer required.

Last September, I started getting my TV from digital broadcasts (as described in an article at the time). One of the consistent problems since then is that channel 2-1 has consistent audio drop-outs, often coupled with severe pixellation or total loss of the video. The problem seemed to be worse at night.

In the course of fiddling with the antenna, I noticed that if the antenna were pointed up slightly, the signal from channel 2-1 was significantly more stable. I placed a TV Guide under the front of the antenna to tilt it slightly up. There’s a hill between Sutro Tower and my location, so it’s not surprising I got slightly better results by pointing the antenna up slightly towards the crest of the hill.

Even with the slight tilt, the signal still dropped out a few times per hour. With some more experimentation, I discovered that if the antenna elements were vertical, rather than horizontal, channel 2-1 was flawless.

Improving the picture by turning the antenna vertical was a bit of a surprise for me. Antenna elements should line up with the polarization of the broadcast signal. Most TV stations in the U.S. transmit with horizontal polarization. (As far as I can tell, this is a historical tactic used to avoid interference, since most human-caused electromagnetic noise has vertical polarization). In fact, the FCC records for the station show that the digital signal is transmitted with horizontal polarization. Perhaps there is something about my particular geographic location or construction of the dwelling that causes vertical polarization.

If I moved the antenna to a vertical orientation, however, I lost all the other stations (4, 5, 7, 20, and 44) from the same tower. Fortunately, electromagnetic waves are vectors. By tilting the antenna to one side, I could get a combination of both the vertical and horizontal signals, and get all the channels without signal dropouts.

In the end, I wound up propping up one side to get the antenna orientation I wanted. It now points slightly up towards the transmission tower, and is tilted to one side. All the local channels off the transmission tower have been rock-solid since I made the change a week ago.

Several variations seem to have come to light. For example, SymbOS.Lasco.A is transmitted through Bluetooth as a .sis file - See this website
Then there’s SymbOS.Cabir, a proof-of-concept worm that replicates on Series 60 phones. This worm repeatedly sends itself to the first Bluetooth-enabled device that it can find, regardless of the type of device. We listed some details in a recent article.

Symbian experts like Steve Litchfield simply say bogus… “no-one can pass a virus to your Symbian smartphone over Bluetooth without your knowledge” - so why then is there PR just about every day that cites something to the effect of Symbian device users beware…. Panic.. you bet… hype… you bet. However, to be safe excercise good judgement and smart computing or blutoothing (is that really a word??).

If it helps, here’s some useful tools for Symbian device users looking for protection…

SimWorks
F-Secure
Trend Micro Mobile Security

Have you ever contracted a virus on your Symbian device? If so I’d love to hear from you.

Related link: http://www.symbianone.com

I hope to take advantage of this great forum by sharing with you some of the coolest and most interesting developments that we come accross, particularly involving wireless application development trends, issues, and concerns, particulalrly involving the Symbian smartphone OS. As founder and managing editor at symbianone.com I’m fortunate enough to be in touch with key players in the mobile arena, particularly the device makers and application developers creating great hardware and apps for the latest and greatest devices and smartphones. I look forward to sharing loads of great news, rumours, tips and tricks with you all and welcome your feedback.

Please be sure to also visit SymbianOne.com for the latest about the Symbian mobile OS and GISuser.com for the latest about geospatial technologies.

Glenn can always be reached for comment by contacting glenn-at-symbianone-dot-com or simply hit the contact link at symbianone… Cheers

I’m glad to report Switching to VoIP is nearing completion. But I must say, writing this book has been a really enlightening experience. Allow me a moment to bare my soul about it.

I’ve written articles for magazines before, but I think it’s fair to say I’m a first-time author, because writing a 300+ page book for O’Reilly Media is a quite a new experience, indeed. Prior to this, I’ve never had to study a subject so closely; I’ve never had to throw myself at something so hard. Sure, I’ve installed VoIP equipment and programmed VoIP servers, but to write authoritatively about it takes a confidence in the material that’s a notch higher. When you do something for yourself, you can forgive yourself for any mis-steps. When you do something for others, like writing a book, it better be right on.

As I’ve written, I’ve done a lot of what I hesitate to call “second-guessing”, but that’s probably what it is. I write a chapter, and I love it. Then, the next day, I go back and read it again–and this time, I hate it. Or maybe I encounter some esoteric detail in the “real world” that I realize I’ve neglected to put in, and I say to myself, “Man, that would be great as a side bar in the book.”

So I do yet another revision to a chapter I’ve thought was finished on several occassions. And, after I add that sexy nugget of newly-discovered information, I think the chapter is done–again. This has happened more times than I can number with an 8-bit expression.

Then there’s my consistent paranoia about making sure every fact is straight, clearly presented, and relevant. Is this paragraph dull? Is it worthwhile? Who is going to benefit from a 2-page essay on budgeting a VoIP project? Is that too much space on a non-technical subject in an otherwise-technical book?

Am I blathering on here like an incoherent windbag? Chances are, if I think I am–I am.

I’ve just spent all week re-reading my manuscripts, circling grammar mistakes and typos that I swear I’ve already fixed, and combing the concepts I’ve presented, and the order in which I’ve presented them. As it turns out, I’ve done more wholesale paragraph elimination than I ever figured I would need to do.

I say to my wife, “Kelly, this book is going to be good.”

I do believe it is going to be well-received and helpful to the burgeoning community of the VoIP-curious. I remind myself how needed this book is. Where else can you find a well-presented source of hands-on learning material for enterprise Voice Over IP that is geared towards I.T. people and not telecom nerds? Nowhere. O’Reilly will be first to market with it. That fact alone gives me a lot of satisfaction. I’ve been a part of something new, something fresh, something whose timing was perfect and whose content was relevant.

Now that you know how I feel, let me get back to work. The writing phase of this project is almost done, but there’s a lot of work yet to be done. O’Reilly’s editorial staff–who have thus far been fantastically supportive–will review the book with a deep glare, their artists will create the illustrations, their copy editors will fix the grammar mistakes to which I’ve doubtless been oblivious.

So, it’s back to the office. I have one chapter left to write, three appendices to edit, and a whole lot of proofreading to do. I’ll update you when all that’s done.

What do you want to learn about VoIP? What aspects of VoIP aren’t covered well enough by the learning material that’s presently available?

Related link: http://www.rfidtribe.com/event.html

I will be speaking at the RFID Tribe chapter meeting in Dallas on the 21st of January. My topic is “Fugitives From the Server Room: Negotiating With Devices on the Edge.” Chris Hanebeck of GlobeRanger will also be speaking on “Next Generation RFID-enabled Supply Chain Networks”
RFID Tribe itself seems like a neat idea. It brings together business and engineering types with an interest in RFID to share info and business cards in a low-marketing zone. I spoke with the founder of RFID Tribe, Mark Johnson, and he seems committed to remaining vendor agnostic, though my official Sun Java Mind Control Ray(tm) will prevail regardless.
What impresses me about these folks is the clever set of incentives they’ve built into the organization to reward participation. The structure reminds me of the anti-leech code in a good P2P or (to show my age) the upload/download ratios on a BBS systems[1]. Mark better be careful, when the Singularity comes, this thing could turn into a Charlie Stross style, sentient organization.

–
1. of which all right thinking people know that Gman’s Rock City U.S.A. was the very best BBS of all time.

Do you know of or belong to any other RFID organizations? Do you (falsely) believe some other BBS was better than Rock City?