Why is D-Star being pushed so hard for emergency communications?
This morning I received the ARRL's ARES E-Letter (24 Feb 2010) and found it riddled with how Icom's D-Star system was so great and the answer to all our problems. The entire letter seemed to be one big advertisement for Icom, actually. What I can't understand is why the ARRL feels like D-Star is such a good idea. Let's look at the facts of the system.
- D-Star uses a proprietary codec for its digital voice. So everyone that purchases a D-Star transceiver is also shelling out money to buy the license to use that codec. So unless you are using Icom's proprietary equipment you won't be heard during an emergency. The same thing was happening in the public safety market. Different vendors were using different, proprietary codecs for digital voice. This became a huge interoperability problem. The solution was simple, however. The Association of Public Safety Communications Officials International (APCO) created Project 25 (P25) which created a standard for digital voice and data among all public safety agencies in world. This was an international standardization that has worked quite well. The codecs used for P25 are open source and thus available for everyone to use, for free. Because of this, P25 has taken off and is available in radios made by a variety of manufacturers. Unfortunately Icom wasn't very forward thinking and did not get on board with P25.
- D-Star linking occurs only via TCP/IP. So unless you can setup a wireless network with enough bandwidth to handle the data connection you will be using the Internet to link up your repeaters to other repeaters. As this is for emergencies, shouldn't you be using non-Internet methods of linking? If I can just use the Internet then I have no need for amateur radio, you can go home now.
- D-Star transceivers are expensive! You can expect to pay $200 more for a D-Star-enabled handheld transceiver than you would for one that is not D-Star-enabled. For $30 more, I could buy Kenwood's D-710 mobile radio with APRS and have 50-watts of communicating power. Plus APRS specification is completely open and can be, and has been, implemented by numerous people and manufacturers.
- D-Star won't have the same range that analog will. Remember when cell phones went from analog to digital? There were spots that I used to be able to make a phone call that I couldn't when digital came about. The reason is simple, actually. The computer in your head (your brain) can understand what is being said even in bad conditions. The computer in that repeater control cannot, however, and a dropped packet means communications lost. During an emergency I don't think lost communication is an option.
So all this said, what are the pros to D-Star? Hmmm... I actually cannot think of any. If anything it makes us complacent about how to do our jobs and makes us reliant on a communications medium that we cannot control. I'd be more apt to get behind a P25 system than a D-Star system because of the openness of the system but even that has limitations.