Friday, September 25, 2009
The basic points, in my reading: (1) Amateur Radio operators, by FCC regulation and with narrow exceptions, are volunteers and are normally not allowed to communicate when they have a pecuniary interest, for example, on behalf of their employers. (2) Organizations may not use Amateur Radio frequencies when there are alternate licensed (or unlicensed) radio services that can be used, such as the Land Mobile or Commercial Mobile services. (3) Provisions in the FCC regulations suspending some normal rules during time of disaster or in emergency situations do not allow organizations to plan communications on Amateur frequencies without obeying FCC licensing regulations.
The ARRL Board does not cite specific instances of real or planned abuse or exploitation of Amateur frequencies, but we can guess what they might be. An organization wants to assure business continuity by using ham equipment and frequencies, either with or without help from licensed Amateur operators. There might be many variations of this picture, ranging from purely commercial entities to non-profit charitable organizations that want to provide community services, but with in-house paid personnel, with or without licenses. In any case, the nature of the Amateur Radio Service and its frequency allocations would be put in jeopardy by operations that are making an end-run around inconvenient FCC regulations.
The League Board makes a clear and urgent call for Amateurs and Amateur organizations to read and understand the relevant FCC regulations, and to carry the message to all forums where emergency communications services are being planned and coordinated.
Beyond their informative and persuasive arguments about appropriate use of Amateur frequencies, I though the Board's consideration of the roles of the FCC, the Amateur Radio community, and the ARRL itself to be very interesting. We must remind ourselves that Amateur Radio is largely a self-policing enterprise. It is unrealistic and unwise to expect the FCC to specify precisely which uses are acceptable or not acceptable. (Be careful what you ask for!) It is up to each of us to understand the law and the regulations and to develop a consensus of what kinds of operations to support or to oppose.
(Reading between the lines, now.) The scary scenario we want to prevent is having large governmental, non-profit, or for-profit organizations, see how sweet the inexpensive, relatively informal world of Amateur Radio is, as a way to satisfy their urgent needs. In some cases, Amateur groups may be only too willing to accept generous donations of equipment and other support in the name of emergency communications operations. In reality some of these large organizations have a lot of economic and political power and could turn around and actually threaten Amateur Radio spectrum in the future, by co-opting our frequencies in the name of emergency services.
The commercialization issue is just one example, to my mind, of the growing tension between Amateur Radio, which is traditionally shoe-string, informal, improvisational, and local, as against the well resourced, highly structured, and even quasi-military environment of large-scale emergency response organizations and corporations. Good luck to the ARRL, and to us all, in working that one out.
Update: I should explain that I've been a ham for 50+ years, but apart from the odd Field Day, have had little involvement in the emergency communications side of Amateur Radio. (I admire those who do!) I like DX and casual contacts using CW, PSK31, and even SSB. And I do other stuff that you can read about on this blog.
Saturday, September 05, 2009
Lately, I've been wondering what aspects of Amateur Radio would benefit from high performance computing technology. This is prompted by my latest PC - built around an Intel Core i7 processor with 6 GB of RAM. This CPU has 4 cores and 8 logical (hyperthreaded) processors. The benchmark results are very nice: 20,500 Whetstone MIPS (floating) and 45,200 Dhrystone MIPS (scalar) across 8 simultaneous threads. [BOINC's built-in benchmarking - not to be taken at face value!] In addition, we have graphics processors (GPUs) that can be programmed with CUDA, OpenCL, and similar methods.
Some general areas that occur to me:
- Digital Signal Processing (Audio-ish) - This is the technology behind much of today's Software-Defined Radio (SDR). A significant amount of processing is required for mixing, modulating, and demodulating signals. Dynamic spectral displays are useful. However, the actual amount of horsepower required for typical amateur applications is fairly limited. In most cases, the bandwidth of interest is less than 128 kHz (the range of high-end audio cards for band monitoring displays) and very often less than 3 kHz - the maximum audio bandpass of most communications transceivers. As long as we are working with audio-type signals - PSK31, Olivia, RTTY, and SSB, we are not likely to tax the latest CPUs. You can use more power if you want to listen to many channels at once, but even so...
- DSP (Video) - Modern HDTV signals require a lot of processing. In production work, this would mostly be done in special-purpose processors (I think), but amateurs might prefer to operate with commodity PC and GPU hardware. I am not aware of amateur HDTV work for over the air transmission, but there may well be some. My initial look at HDTV (and DTV) was discouraging. The sheer numerology of options is overwhelming -- although of course, you may only need one mode for ham work.
- DSP (Video 3D) - How about ham communications through 3D immersive environments? Four-pi visual fields, multichannel sound: you could get the gamers into that! (But why ham radio? Why not FIOS-type connections? We can offer off-grid operation and mobility away from cell towers!)
- Radio Science - Propagation Analysis and Prediction through detailed atmospheric modeling, ray tracing, etc. This could be extended to real-time monitoring of the HF bands at points around the world, and trying to build up a real-time DX prediction service.
- Exotic wideband signalling. Using microwave bands and pursuing highest bandwidths. Would this be more a question of very fast D/A conversion and I/O more than general purpose computing?
There must be more areas for HPC in Amateur Radio. As a long-time HF operator, I'd like to be able to translate CPU power into greater sensitivity and interference rejection. We can certainly consider computationally intensive modulation and demodulation schemes, but it's not clear what returns are available in a channel's SNR given the practical limits on transmitter power, modulation bandwidth, antennas, etc. The ionosphere degrades the signal so that frequency resolution below about 1 Hz or so is not going to be very productive. How can a "supercomputer" overcome that?
[This is cross-posted with my SourceForge blog: http://sourceforge.net/userapps/wordpress/aa6e/. Why do I have an SF blog? For topics relating to open source software, to see what WordPress is all about? Something like that!]