Tuesday, May 06, 2008

Ham Radio, Internet, and the Cell Phone

A recent commentator in my blog remarked that there has been a declining interest in amateur radio, citing as a reason for this an increase in the availability of computers and the Internet.

While I think wider availability of the Internet may be a factor, I don't think it's a major one. The Internet is not really a substitute for amateur radio. While both do permit relatively inexpensive long-range communications, the nature of those communications are quite different. Amateur radio permits mostly immediate, relatively low bandwidth, personal contacts between people who would otherwise likely never meet. While there are those in amateur radio who pursue packet radio and other store-and-forward technologies, even in their heyday these were not a major aspect of the hobby for most people involved. (In part, this is due to the regulations that strictly limit third-party traffic on ham radio frequencies, which has amongst their effect making it impossible to use ham radio to connect directly to the Internet.) The main appeal to most people in the avocation has always been talking to other people at a long distance, from wherever they might happen to be.

No, it's not the Internet that is killing ham radio. If anything, the Internet is helping it. What is killing ham radio, at least in the West, is the cellphone. Prior to the cellphone, there were very few options for people who wanted reliable mobile communications. There was, of course, CB, but it's only good for a few miles if you follow the rules (which most of the people using it don't, sadly) and only a few more miles after that even if you don't. And CB is also full of obnoxious loudmouths who seem to exist only to hear themselves talk (they're not interested in having an actual conversation), making it nearly useless as a personal communication service anyway. You could, of course, obtain a business class license and use "color-dot" radios, but those licenses are not particularly cheap and the radios (at least back before 1990) also not all that cheap. Practical for a business; not practical for people who just want to be able to talk to one another when they're out and about.

There was one final option: you could get an amateur radio license and use VHF or UHF handhelds. Relatively affordable and reasonably sized two-meter (144-148 MHz) handhelds were available for the amateur service long before cellphones were widely available to the public. In simplex mode a two-meter HT (handheld transceiver) has a modest but decent range; used in conjunction with a well-located amateur repeater station a group of hams with two-meter HTs could easily maintain contact with one another over the area of a mid-sized city. The introduction of the "no-code Tech" license in the United States in 1991 helped here; this license gave broad privileges on VHF and higher frequencies without requiring the licensee to learn Morse code and made it much easier to attract technically competent people to the hobby who didn't want to take the time to learn Morse (a technology which computers have largely made obsolete). This did lead to a surge in licensing, but many of those who got their licenses in 1991 have since drifted away.

Enter cell phones. While the idea of cellular radio was invented in 1947, and the cell phone itself in 1973, the early models were large, expensive, and had very limited service areas. (Even as late as 1995 a cell phone was substantially more expensive than a 2m HT, and the HT has no "service contract" that has to be paid monthly; even if you used a repeater and the repeater operator asked that you join the club and pay dues, the dues were probably less than what you'd pay for a cell phone contract.) It wasn't until the late 90s that cellphones became widespread, and not until the early 2000s before they became ubiquitous. Now, for a relatively small fee, can get the same thing using a cellphone, and on top of that call anyone else they might care to talk to as well. Given a choice between a VHF HT or a cellphone, the cellphone wins nearly hands-down for this sort of communication in almost all situations now.

That's not to say that there's nothing interesting going on in the amateur radio world; it's not just a bunch of nerds in their garages beeping at one another in Morse code (although, to be fair, there still is some of that going on).

One big thing right now in radio seems to be software-defined radios (SDRs), and this is an area where free software can and should be getting involved. Traditional radios have used discrete, specialized circuits designed specifically for the application at hand, which means a given radio is good for, say 2m FM reception but not much use for anything else. "All mode" radios can receive and transmit multiple modulations, but they do this typically by having physical (or electronic) switches that gate the signal to the appropriate modulators and product detectors, which introduces the possibility of loss and makes the radio much more complicated (and therefore expensive). SDRs are different.

In its ultimate form, an SDR is a analog-to-digital converter (ADC) attached directly to an antenna. As there are few ADCs that can process signals at the frequencies used for many forms of radio (the current limit is around 40 megahertz), and there are other practical limitations, what is done instead is a traditional front-end is used to select a portion of the radio spectrum to receive, which is then preconditioned using (typically) a superheterodyne mixer to produce an intermediate frequency signal suitable to be shoved into the ADC. Everything else is done by the ADC. Transmitting works the same way, in reverse; a digital-to-analog converter (DAC) generates an IF signal that is then either merely amplified and put directly on the antenna (for sufficiently low frequencies) or fed into appropriate mixers or transverters for VHF and up. Since all the digital signal processing is done by the computer, the radio can have all of its functionality, other than its fundamental RF receive and transmit frequency capabilities, reprogrammed merely be changing the software load. Since virtually all computers out there today have ADCs and DACs in them, in the form of a sound card, this is something that most anyone with a computer can do with minimal investment. For somewhat more investment, there are hardware solutions (such as the Universal Software Radio Peripheral) that offer more capability by providing more powerful ADCs and DACs than are found in your average sound card, along with a FPGA solution to allow for faster processing. And, of course, the opportunity for homebrew solutions is huge here, too.

There is already an open-source project working in this area: GNU Radio. One of the reason it's important for open-source advocates to get involved in this now is that SDRs are quite likely the direction the radio industry is going. And, of course, the solutions being created by the commercial manufacturers are locked-up-tight proprietary you-can't-touch-this approaches that limit freedom just as much as any other proprietary solution. We need for there to be open alternatives so that people will be inclined to adopt open approaches that let us use the hardware we pay for the way we want to. There are some freakingly neat things being done by the GNU Radio people.

There's also some very fascinating work in weak signal developing codes and methods that can punch a message through noise, which should appeal to those with interests in compression, information theory, and data reconstruction. Morse is surprisingly good for this purpose, but there are better codes out there. The computer has really revolutionized this area of the hobby as well (although not without some controversy).

I haven't mentioned Echolink or IRLP, either; both of these are fusions between ham radio and the Internet.

In any case, I don't think computers and the Internet are killing ham radio. The cellphone, while it certainly has had an impact, is not the real problem, either. I think the real problem is much more complicated and has to do with attitudes toward engineering and science in Western society more than anything else. Ham radio is very much alive in Japan and in much of the developing world, after all.

And we definitely need more hams; with our increasing dependence on telecommunications for everything we do, we need to have ham radio operators equipped, trained, and ready for when disaster strikes and the grid falls down. (Which is also why we really do need to keep Morse: it's just about the best way to punch a message through noise that doesn't require complicated equipment, just a trained operator and something that you can pulse on and off. All these other fancy digital modes are basically useless without a computer.) It's for this reason as much as anything else that I carry my HT with me most of the time.

The FCC last year removed all Morse code requirements (as have most other countries) for amateur radio licensing, and this appears to have caused another upsurge in interest. It'll be interesting to see how long it lasts.