Bandwidth a Myth? -- Should bandwidth be a primary component in the regulation of digital amateur radio communication and more broadly as a primary component in the regulation of any amateur radio mode? -- The basic idea of radio frequency regulation is that a station is allocated a specific (carrier or center) frequency and a surrounding range of frequencies for the modulation (i.e., intelligence carried on the carrier). For CW (“Continues Wave” or pulse) this is simple. The CW modulation is the carrier being turned on and off for the modulation (with some allowance for the fact that pulsed square-wave on-and-off carrier does occupy more frequency space than a simple unmodulated carrier). For AM (Amplitude Modulation) the carrier stands in the middle and the variable (audio) modulation being added above and below the carrier. SSB (Single Side Band) is AM minus the carrier and one side of the audio modulation. FM (Frequency Modulation or phase modulation) is moving the carrier off center in response to the modulation. This all can easily be graphed in Cartesian coordinates with frequency on the x-axis and amplitude on the y- axis for the paniscope display, or frequency on the x-axis and time on the y-axis for a waterfall display. [It is not necessary to digress into spreadspectrum or other more complex modulation modes for the purposes of this comment. It should be noted than when the time clock is slowed way down, frequency hopping spreadspectrum and trunk- ed radio systems reveal communication on preallocated frequencies being used.] For most radio services, the license from the spectrum regulator gives the licensee access to one assigned frequency (plus and minus a modulation width and some guard band space) or several assigned frequencies. The user has a reasonable expectation from encroachment by other users. The assigned frequency can also be more broadly called a “channel” (especially in analog television with an audio and a visual element). Even cellular telephone allocation work as groupings of specific defined frequencies, even if this is invisible and no concern to the ordinary user. WiFi has its predefined channels. For the user of household television or AM-FM radio this channelization of broadcast and cable stations is shown in the ability to click up and down the “dial” from station to station, rather than the old pre-digital need to manually “tune in” AM and FM radio stations. A large exception to this assigned frequency (or channel) world of spectrum governance is the Amateur Radio Service. Amateur radio is given numerous broad bands of radio frequencies to be shared by all licensed operators/stations (subject to level of operator license and some division by type of modulation). In many ways, it is similar to the old fashion telephone party line with no one amateur or group of amateurs having any legal claim to any particular frequency spot. Day-to-day amateur radio works with common courtesy and acceptance of a fair amount of interference from nearby radio signals of other amateur radio stations a little higher or lower in frequency. Courtesy includes listening on frequency before transmitting, avoiding deliberate interference or prolonged monologues, and having a clean signal that does not splatter up and down the band. The allocation of numerous broad bands of frequencies is also rooted in the radio experimenter history of amateur radio which continues today and into the future. By the use of different radio frequency bands the amateur can explore the still not completely charted word of radio propagation (including interaction with the not fully understood variable of weather, seasons, and the sun cycle). The amateur radio operator is free to explore new types of radio modulation – which is the basis of this RM-11708 filing to allow for more freedom is possible digital (non-voice) modulation signals. Other licensed radio services limit the user to a specified type of modulation and narrow channel or channels for a specified use, and essentially prohibit experimentation by the user. The heart of the traditional regulation of radio spectrum is to narrowly limit the user, form of modulation, and to specific frequency or channel (frequencies or channels). [The extent of detailed regulation is less in style in the age of mandated “frequency actions” but still exists in the qualification for possible bidders in the actions and industry standards for equipment that is eventually used.] Even in the experimental and developmental radio service, the applicant is require to carefully explain the planned use and licenses are granted for only a limited period of time. The amateur radio operator is much freer to do their exploration and work out their evolving ideas over time than other licensed radio services. Amateur operators can build and repair their own equipment with minimal restrictions. Only the amateur radio operator has a VFO (Variable Frequency Oscillator) dial on his or her radio transmitter/transceiver – everyone else has equipment locked into a predefined channel or multiple channels. Most non-amateur radio users have no idea of what radio frequency they are using or how box they are using works on the inside. The non-amateur uses type accepted (etc.) boxes and they can not open up the equipment and do their own repairs and modifications. To be honest, the typical amateur radio operator is not a white lab-coated scientist or on the trail of some Nobel Prize winning world-changing discovery, but their day-by-day operation does add their skill and knowledge of Hertzian wave phenomena and electronics. … To get more directly back to the subject at hand of RM-11708 and “Bandwidth a Myth?” The amateur radio operator is limited to the amateur radio band frequencies and transmitter output power appropriate to his or license (or control operator’s license, to be technical). The amateur radio operator license and the amateur radio station (e.g., call sign) is NOT limited in the number of transmitters that they can have on the air at any one time. Amateur radio club stations frequently have multiple operating positions and transmitters. The American Radio Relay League (ARRL) uses this type of setup at their station W1AW to send code practice and bulletin transmissions on a regular basis. Even an ordinary amateur can be using a HF (high frequency, short wave) transceiver while talking on the side over VHF-UHF walky-talky, for two transmitters. The FCC rules do not prohibit one amateur operator from having two transmitters with one on the 80-meter amateur band and the other on the 40-meter amateur band, both being keyed at the same time. And this number of transmitters is not just limited to two for any amateur radio license. In the commercial and military point-to-point services, his is called “frequency diversity” to help get message through 24-7 despite the variability and unpredictability of radio wave propagation at any one frequency (including phase fading and possible interference). With enough resources, the amateur could do the same, including sending parallel emissions from two transmitters on the same band (i.e., on 80-meters using both 3.510 mHz and 3.590 mHz. (This point will be further developed later in this comment and related back to regulation by bandwidth for the Amateur Radio Service.) Another fact is that on-the-air regulation of radio signals does not really care how the signal was generated inside the originating station’s equipment – only the result being emitted from the originating station’s antenna. Whether the modulation (intelligence) is applied at a low level and then amplified through several stages before being emitted by the antenna or is applied at a high level in the final stage connected to the antenna in the transmitter makes no difference to the spectrum regulator (or to the person at the receiving end). It is not how it is done but the resulting radio signal emitted by the antenna. Traditionally, a CW signal was generated by tuning on-and-off some stage of the transmitted while sending the letters and message. Over the air, there was the carrier signal present or not present for CW. For RTTY (Radio Teletype) the transmitter frequency was shifted between two set frequencies, usually 850 or 170 Hz apart in amateur radio practice. RTTY could be generated by two transmitters, one for each frequency care that one transmitter could be keyed at any one time, the easier approach was to shift the low level transmitter’s oscillator between the two frequencies and amplify this signal. The over-the-air result was the same and the receiving station could not tell the difference between the two transmitters or one shifting transmitter. The regulator did not as long as the over-the-air signal was the same. In recent years (since the 1950s) there has been a change with the ready availability of amateur radio SSB (Single Side Band) transceivers. The SSB transceivers were originally developed for voice communication. The more efficient 3 kHz SSB voice signals have pushed aside the older 6 kHz wide AM voices signals from regular use on the HF amateur radio bands. This widespread acceptance of SSB voice transceivers has also changed digital transmissions in amateur radio. A digital radio signal can be created by adding a tone or tones into the audio input of a SSB transceiver. Disconnect the microphone and connect a tone source (i.e., modem) to the SSB transceiver and the antenna can emit a digital signal. A keyed single tone provides a CW signal. A variable or multiple tone generator provides RTTY or other digital mode. This SSB signal is limited by the transceivers voice filters to 2.5 to 3.0 kHz audio bandwidth.