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The real cost of SMS.
hardware : by Corey - December 28th 2008, 10:26PM
hardware
Our good friend ltd posted a link to this story in The New York Times concerning how wireless carriers are essentially screwing over the consumer when it comes to the charge for text messages. While that point is more true than any carrier would like you to know, some of the details provided as a basis for this claim are incomplete.

But first, some nomenclature! The technical name for a text message is SMS (Short Message Service). It was designed and originally codified for use with GSM networks and devices during the 1980s. It consists of a short message, usually 160 total ASCII characters or less in length, transmitted between devices.

Another term thrown around is control channel. The control channel represents the very small piece of RF spectrum that is always active and serves as the, "always on" link between your device (usually a phone) and the network. All network information is transmitted over the control channel, including what RF channel to use and at which power setting to operate. Additionally, it is used to transmit paging messages, which is also why the control channel is often called the paging channel. Those page messages include alerts about incoming calls, outgoing calls from your device, incoming call waiting calls, network alerts, and other network/device communications. The other channel is called traffic channel, and is utilized when a call is made (either voice or data).

With that in mind, the central point of most of the articles published about this story is that SMS utilizes the control channel of the network, which does not require a traffic channel connection to be made that takes up valuable spectrum on a particular sector of a cell phone tower.

This point is flawed. Specifically, SMS messages are designed to roll over to the traffic channel any time the control channel is too busy to handle the additional traffic.

Continue reading...

( Comments : 5 | Full article )

 
Rockmite 20m
radio : by Tommy - December 22nd 2008, 12:57AM
radio
After almost a year of procrastination I got around to finishing a Rockmite 20 radio kit. The Rockmite is a single-frequency crystal-controlled ("rock-bound") low-power CW HF radio. Say that 10 times fast!

I bought the kit sometime last year and just never finished building it. I had all of the components soldered in, but I never mounted the board in any enclosure. W5USJ, Chuck, Don, K5DW, gave me a metal enclosure during a North East Texas QRP Club meeting. It wasn't until last Friday that did anything with it. I knew the Rockmite needed a home, and here was a nice case for it. I drilled some holes in the cabinet, more or less eyeballing it. They're not perfectly aligned, but pretty close. So now the little radio is mounted, all of the connectors are soldered in and the radio is functional.

It only puts out about W at 14.060MHz, on the 20m amateur radio band, but because I mostly operate during the afternoons, 20m is my favorite band for now. I may need to boost myself up to a "full gallon" QRP and get a 5W amplifier like the one Chuck designed, which I might get from QRPme.

Also on my "to do" list, is to add a PicoKeyer chip to the radio which greatly adds to the experience of using it.

update: I got the PicoKeyer chip installed this afternoon. I love the features it provides. The Memory Keyer is vital for QRP work and the hands-free "Tune" feature is great for field-portable antennas. Most of the other features I don't use, but I still think the chip should be incorporated into the original design.

tags: qrp ham_radio kit

( Comments : 0 | Full article )

 
TheGreatHatsby
news : by Tommy - December 12th 2008, 12:13AM
news
Very interesting and very odd. I'm sitting here writing my last paper of the semester and I get an IM.
The conversation goes as follows:
    CuddlingCoho: Hey.
    GrendelT: hi, who's this?
    CuddlingCoho: I should ask the same. you started the conversation
    GrendelT: did i? when?
    CuddlingCoho: [12:56:07 AM] InstructiveCoho: Hey.
    GrendelT: (11:55:59 PM) CuddlingCoho: Hey.
    GrendelT: so, apparently you're on the East Coast...
    CuddlingCoho: yeah... so do I show up as "CuddlingCoho"?
    GrendelT yeah, and I guess I'm "Instructive"
    CuddlingCoho: you show up as "InstructiveCoho"
    ...
From there we exchanged actual screennames. I had assumed we were somehow going through some sort of IM proxy, hence the altered screennames at the recipient's end. A little bit of Googling for "Coho" returned this tidbit of information about TheGreatHatsby.

Apparently this little game has been running around on the net for quite some time, coming and going as interests change. After speaking with "axelstudios", aka CuddlingCoho, we discovered we had both just "dugg" a story on Digg. I'm guessing this phishing bot crawls Digg's live activity page to find users that are currently on, goes to their user profile page and screenscrapes their IM screenname. The trap is set and one IM between two random strangers fires off the lulz.
Quite brilliant in my opinion. I'd like to run it for a little bit just to read some of the IM conversation logs.

( Comments : 0 | Full article )

 
Christmas decor
neodux : by Tommy - December 8th 2008, 09:53PM
neodux
I almost compeltely forgot to add the annual neodux Christmas decorations! As you can see, they're now safely in place. A gentle snow falls and a we now have a festive neodux logo.

In the real world, the lights are up on our apartment - we have the coolest light display on the block! (There's only one other apartment with lights.) Thanksgiving weekend, Jennifer and I went and cut down a tree at a local tree farm and decorated it all nice and pretty. We're all done with our Christmas shopping, and now Sirius is playing non-stop Christmas music on the Cinemagic channel. Christmas time is officially here.

And here's a great video of a dog having fun in the snow.

update: Once again, here's everyone's wishlists: Greg's wishlist, Tommy's wishlist, Jennifer's wishlist, Jeff's wishlist, Mom's wishlist

tags: neodux christmas

( Comments : 0 | Full article )

 
Fantastic Contraption
games : by Tommy - November 28th 2008, 03:43PM
games
Fantastic Contraption is a great flash-based game. It allows you great flexibility in the design of your contraption. The goal of the game is explained in the tutorial - essentially all you're trying to do is get the pink ball into the pink area. Sounds simple enough, right? Each level gives you a different challenge. Either some pitfall or obstacle is in your way.

Many of you have probably already played, but I'd like to see your contraptions in the comments section of this post.

( Comments : 45 | Full article )

 
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