Radio Preppers

General Category => Net Activity => Topic started by: NerdyJohn on September 03, 2012, 10:56:52 AM

Title: D-Star anyone?
Post by: NerdyJohn on September 03, 2012, 10:56:52 AM
With the exception of the total loss of infrastructure, D-Star is a great mode for emergencies, especially if you have a DVAP.  And in simplex mode, it's quite secure since it's digital.   

I would love to set up some comms with fellow preppers on D-Star.  So who's using D-Star? 
Title: Re: D-Star anyone?
Post by: Scott on September 05, 2012, 12:02:35 AM
*crickets*

1.  Too expensive
2.  Manufacturer-specific (i.e., Icom)
3.  Infrastructure-dependent
4.  No benefit over competing linking technologies
-->  IRLP
-->  EchoLink
-->  AllStar

D-star should be good and dead in a couple of years.  It's losing traction, not gaining.
Title: Re: D-Star anyone?
Post by: Mitch on September 18, 2012, 01:14:12 PM
Short answer to your question is no, not really... I'll try to explain the why:


I've explored a bit of D-Star on my IC-92AD HT (Handheld Transceiver) and DVAP (Digital Voice Access Point).

Managed to contact my father in California from Texas on my 100mW HT; sounded like he was sitting in the same room. I was impressed with that! Yes, there is a lot of infrastructure between the two of us -> I was just happy I figured it out! D-Star (non-simplex) in it's current configuration isn't the friendliest beast. This really doesn't have a true bearing on this thread, but hang on and I'll tie it in later.

In most things I agree with Scott about the disadvantages D-Star currently has. I'd just like to touch on those points one-by-one.

1. All newer technology is expensive at first. After wider adoption (if it makes it that far) the industry matures more and competition crops up and prices will drop to a reasonable level.

2. The only thing manufacturer specific is the Vocoder chip used in D-Star radios. The chip is for sale to anyone for integration into a radio. It just so happens that Icom is the only one of the big 3 making radios with the Vocoder chip installled. Refer to #1 for attendant dynamic. When the Japanese HAM inventors eventually lose any intellectual rights or someone just figures out how to copy it's inner workings you will begin to see some chip proliferation going on!

3. The infrastructure dependancy of D-Star is exactly the same as all competing linking technologies, but I think D-Star can carry more benefits over to the simplex/local portable repeater realm than the others. This makes it more relevant in the SHTF scenario (what preppers are more interested in). Keep in mind I know very little about IRLP, Echolink, and Allstar. For all intent and purpose I don't know a bunch about D-Star either!  :o

4. The main benefit I see in D-Star over other VOIP (Voice Over Internet Protocols) or another digital protocol links into #3 above. That benefit is the Vocoder chip, its function is to turn a human voice input into an efficient smaller bandwidth digital signal and interpret similar incoming signals back into human speech for the receiver. This is the important point in my mini-novel: In general I feel that a properly engineered hardware solution beats the tar out of a software solution every day, this makes the one chip solution superior by far to competing technologies. The hard part of digital communications is being performed in a miraculous way in a single little chip internal to your HT instead of having to lug around a computer! Also, you've just bypassed 50 steps that a very technologically savvy HAM has to perform to "do digital" and the part the end users deal with is voice (no special training like learning Morse code). Let me tell you- learning PSK-31 was a lot harder and more involved than learning D-Star simplex.

D-Star might be good and dead in a couple of years (I don't know), but I'm thinking the good old smaller/faster/lighter/cheaper engineering mentality will keep this "shrink it all on one chip" technology alive for us to use in the future of HAM radio.

If I can have a set of radios that I can use to talk to my group that has a SNR (Signal to Noise Ratio) two orders of magnitude better than the human ear for voice with a completely transparent interface I win. If I have a set of radios that can communicate while only people with that vocoder chip can hear me in a TEOTWAWKI situation I'm closer to winning.

Back to the original question... I know I ramble! Every time I've contacted my father over D-Star rag chewing has been out because there is always some sort of net in progress on the reflectors out there. The first time it was embarrasing and every time since it's just been annoying so it's killed my desire for linked D-Star operation. My original research into D-Star led me to believe there would be some level of call sign squelching, but experience has shown me otherwise. Until something about the experience changes I don't really desire to talk on reflectors out there without good purpose. If you need a clueless HAM on the other end to help you test your D-Star mojo I might partake!  :D