Saturday, August 28, 2010

The IT-Who?

T1B01: What is the ITU?

  1. An agency of the United States Department of Telecommunications Management
  2. A United Nations agency for information and communication technology issues
  3. An independent frequency coordination agency
  4. A department of the FCC

The correct answer is B–A United Nations agency for information and communication technology issues.

(Authority: 97.3(a)(28))

I touched on this topic back when talking about T1A02. The International Telecommunications Union, or ITU, is a very important entity in the broader scheme of radio regulation. The ITU is an agency of the United Nations that deals with information and communication technology; prior to being adopted into the United Nations it was a treaty organization that dealt primarily with the cooperative regulation of telegraphy and other uses of radio across international borders. As radio signals
have a bad habit of refusing to stop at national boundaries, this is
pretty much necessary, especially with respect to the world-reaching HF
bands, in which a station in South America can easily interfere with a
station in Russia. The ITU's rules do not apply directly to amateurs, or indeed to anyone; rather, the ITU makes recommendations which member nations are encouraged to adopt.

The ITU has a significant influence over amateur radio; in their role of creating the International Table of Allocations, they set aside the spectrum that virtually all countries will reserve for amateur radio operators. An example of how the ITU influences amateur radio arose at the World Administrative Radio Conference (a quadrennial meeting of the ITU) in 1979 that resulted in the so-called "WARC" bands of 30 meters, 17 meters, and 12 meters being opened up to amateur use. The United States has historically been one of the most aggressive protectors of amateur radio at the ITU; few nations have as solid a history of arguing in favor of protecting amateur radio spectrum at the international level.

Friday, August 27, 2010

Special operations: Auxiliary stations

T1A11: Which of the following stations transmits signals over the air from a remote receive site to a repeater for retransmission?

  1. Beacon station
  2. Relay station
  3. Auxiliary station
  4. Message forwarding station

The correct answer is C–Auxiliary station.

(Authority: 97.3(a)(7))

This question broaches, albeit only lightly, the topic of what are called "special operations". There are, in subpart C of the amateur radio regulations, a number of special ways to use, or operate, a radio station that are subject to special rules. These special rules typically impose certain restrictions while relaxing others. For example, an auxiliary station (the topic of this question) is an amateur station (other than a packet station) that is transmitting communications point-to-point within a system of cooperating amateur stations. Auxiliary stations are not permitted to operate on bands below 222 MHz, but are allowed to be automatically controlled (that is, no control operator at the control point). Auxiliary stations which have been coordinated also gain some extra protection against interference, and the general rule against one-way communications is relaxed for auxiliary stations.

The most common use for auxiliary stations is in conjunction with a repeater station. Two linked repeaters may use a pair of auxiliary stations to establish the link, or a remote receiver may use an auxiliary station to connect back to the main transmitter. The W9DUP repeater, operated by the DuPage Amateur Radio Club (of which I am a member) uses an auxiliary station to connect its IRLP node to the repeater, since the IRLP computer cannot be placed at the repeater's location (no Internet access there).

There are several special operations listed in Subpart C, but this is the only one that the NCVEC Question Pool Committee saw fit to include on the Technician pool.

Wednesday, August 18, 2010

Just what is a "radio station"?

T1A10: What is the FCC Part 97 definition of an amateur station?

  1. A station in an Amateur Radio Service consisting of the apparatus necessary for carrying on radio communications
  2. A building where Amateur Radio receivers, transmitters, and RF power amplifiers are installed
  3. Any radio station operated by a non-professional
  4. Any radio station for hobby use

The correct answer is A–A station in an Amateur Radio Service consisting of the apparatus necessary for carrying on radio communications.

(Authority: 97.3(a)(5))

More regulatory jargon here. The correct answer above probably seems a bit circular, in that it essentially says that an amateur station is defined as a station in the amateur radio service. But that's about right. A radio station, generally, is simply any collection of devices that, when used together by a sufficiently trained operator make possible communication via radio. What makes a radio station an "amateur" station, and not some other sort of radio station, is simply the intent of its owner for the station to be used in the amateur radio service, as opposed to some other service. 

Not necessarily every radio owned by an amateur radio operator, or installed at the location of an amateur radio station, will necessarily be part of that amateur's station. For example, my Android phone contains five radios, and yet it is not part of either of my amateur radio stations since currently my Android isn't directly used for radio communication within the amateur service. (Not that it can't be. There are ways I could use my Android in conjunction with other devices to form an amateur radio station. I just haven't yet.)

Also, despite the term, stations need not be stationary. The use of "station" is something of an archaism from the days when radio transmitters were huge and effectively immobile. Modern transmitters can be quite tiny and thus very portable.  Amateurs may also have as many stations as they want. Originally we had to declare to the FCC the location of our "primary" station (and hams in many countries still have to do this) and were allowed only one such "primary" station, but the FCC has long since done away with this. US hams may have as many primary fixed stations as they want (including none), and may have as many additional portable and mobile stations as they can afford. The FCC used to require that certain classes of station (auxiliary, repeater, and beacon stations) be separately licensed, but that requirement has also been done away with and any ham (other than a Novice) may operate any number of stations in one of these special operational modes with no special notice to the FCC.

Tuesday, August 17, 2010

Frequency coordination

T1A08: Which of the following entities recommends transmit/receive channels and other parameters for auxiliary and repeater stations?

  1. Frequency Spectrum Manager
  2. Frequency Coordinator
  3. FCC Regional Field Office
  4. International Telecommunications Union

The correct answer is B–Frequency Coordinator.

(Authority: 97.3(a)(22))

T1A09: Who selects a Frequency Coordinator?

  1. The FCC Office of Spectrum Management and Coordination Policy
  2. The local chapter of the Office of National Council of Independent Frequency Coordinators
  3. Amateur operators in a local or regional area whose stations are eligible to be auxiliary or repeater stations
  4. FCC Regional Field Office

The correct answer is C–Amateur operators in a local or regional area whose stations are eligible to be auxiliary or repeater stations.

(Authority: 97.3(a)(22))

These questions only briefly touch on an issue in part because going deeper into it would touch on areas on which the amateur radio community is in disagreement. The prior version of the Technician pool had two questions on this issue, and one of the questions set forth the arguably controversial position that coordination "reduce[d] interference and promote[d]  proper use of spectrum". I don't know why the NCVEC dumped those two questions in favor of these, but at least these questions are much more closely tied to the actual definitions in the regulations.

Frequency coordination, in general, is the recommendation of operating frequencies (transmit and receive parameters) and other parameters (such as antenna gain, antenna directionality, and selective squelch) to allow multiple repeater and auxiliary stations operating in the same general area to interoperate with a minimum of interference. In the business services frequency coordination by an FCC-recognized frequency coordinator is mandatory for all applicants, and applicants must generally pay a fee to the coordinator for that service. In the amateur service, coordination is strictly optional; however, the regulations give an advantage to repeater and auxiliary stations that do coordinate by essentially giving them priority over uncoordinated stations in an interference dispute, but only when the other interfering station is also a repeater or auxiliary station.

In principle coordination, when properly done, should reduce interference and encourage better utilization of spectrum. Unfortunately, it rarely works out that way. Frequency coordinators have a tendency to become "old boy" clubs that seek to protect the interests of their friends at the expense of those who are not their friends. My personal recommendation with respect to coordination is that one should avail oneself of the service if and when it is offered under reasonable terms, but not let it get in the way of doing something interesting or useful, especially if the coordination body is nonresponsive or unreasonably obstructive.

The other interesting thing about coordinators is that there's no top-down process for selecting one. Instead, the amateur radio operators (at least those eligible to be repeater or auxiliary station operators, which is everyone except Novices, and the FCC has proposed allowing Novices to be repeater operators, too) in an area choose, by no defined process, who their coordinator is. What this means, as far as I can tell, is if enough hams in an area get together and coordinate frequencies amongst themselves, and are recognized as having done so, then they've formed a coordination body and are acting as a "frequency coordinator". The FCC's regulation is very silent on what happens if there's a disagreement over who has jurisdiction in a particular area or if there are two competing entities both claiming to be "the" frequency coordinator for a given area. The key here is that the recognition process is bottom-up rather than top-down.

Finally, don't confuse frequency coordination with the bands established by the FCC (and consistent with ITU policy directives). FCC-set band allocations establish the limits of the frequencies on which an amateur may operate, with specific power limits and modulations. Also do not confuse frequency coordination with the voluntary band plans recommended by the ARRL (and other entities) for general use of frequencies within the limits of the FCC allocations. Frequency coordination is always a specific recommendation for a specific repeater or auxiliary station, based on the particular characteristics and expected usage of that station.

(Edited 8/18 to add T1A09.)

Remote control and intelligence: telecommand and telemetry

T1A06: What is the FCC Part 97 definition of telecommand?

  1. An instruction bulletin issued by the FCC
  2. A one-way radio transmission of measurements at a distance from the measuring instrument
  3. A one-way transmission to initiate, modify or terminate functions of a device at a distance
  4. An instruction from a VEC

The correct answer is C–A one-way transmission to initiate, modify or terminate functions of a device at a distance.

(Authority: 97.3(a)(43))

T1A07: What is the FCC Part 97 definition of telemetry?

  1. An information bulletin issued by the FCC
  2. A one-way transmission to initiate, modify or terminate functions of a device at a distance
  3. A one-way transmission of measurements at a distance from the measuring instrument
  4. An information bulletin from a VEC

The correct answer is C–A one-way transmission of measurements at a distance from the measuring instrument.

(Authority: 97.3(a)(45))

Many of the questions in the first section of the licensing exams are about regulatory jargon, and these two are no exception. I've combined these two into one post because they're basically opposite sides of the same coin. Both are examples of one-way transmissions. Also, notice that the correct answer to each question is a distractor on the other one; it is therefore important to read the question closely to see which one you got.

Telecommand is what your TV remote does: it sends commands to your TV, causing your TV to "initiate, modify, or terminate functions" based on what button you pushed. Of course, your TV remote is probably infrared (very few television remotes are RF these days), but the principle is the same. Perhaps a better example that almost always uses RF is a garage door opener.

Telemetry is using wireless communication to receive data from a measuring device without a physical connection between the measuring device and the reporting or recording device. If you have a wireless weather station, what that uses to send the gathered data back to the base station is telemetry. The same would apply to a wireless security camera; in this case the data being reported back are the images being captured by the camera.

In the context of amateur radio, telecommand is the use of amateur radio frequencies to remotely control a device. This device can be anything at all, but two specific categories stand out: remote control of model craft (often model airplanes), and remote control of space stations; these two categories receive special treatment within the rules. But nearly anything, even another amateur radio station, may be controlled by telecommand.

One of the most common telemetry activities in amateur radio today are APRS telemetry stations (often called "beacons", which is technically a misnomer, as they're not really beacons, but instead telemetry stations). APRS telemetry stations periodically transmit their location (and possibly other data, such as weather observations, environmental conditions, or anything else the station operator feels like reporting) via a packet data format which may then be received by an APRS digipeater and eventually captured by an APRS gateway and published on the Internet.

Space stations: it's all about altitude

T1A05: What is the FCC Part 97 definition of a space station?

  1. Any multi-stage satellite
  2. An Earth satellite that carries one of more amateur operators
  3. An amateur station located less than 25 km above the Earth's surface
  4. An amateur station located more than 50 km above the Earth's surface

The correct answer is D–An amateur station located more than 50 km above the Earth's surface.

(Authority: 97.3(a)(40))

Yet another question about radio regulatory jargon. The term "station" is, itself, specialized jargon in the radio services; despite the name, a "radio station" does not have to be stationary. A "space station" is, within the context of regulated radio (and thus amateur radio), simply a radio station in space. "Space" is defined as "anything more than 50 kilometers above the earth's surface".

The common notion of a space station typically requires that the station be manned; however, this thinking will again throw one off the radio definition. Space stations, in the radio sense, may be remotely operated or automatically controlled, just as any other station, and so a manned presence is not required. Nor is a space station required to be in earth orbit (although as far as I know there are presently no amateur space stations which are not in earth orbit). An especially high-flying balloon would count (although typically amateur radio ballooning activities tend to top out below the roughly 160,000 feet that defines "space"); so would a station on an object in solar orbit (such as, say, Mars) or even on a solar escape trajectory.

Amateur radio space stations have a lot of special rules that apply to them, but unless you plan on launching something into orbit you probably won't need to worry about them. The key to getting this question right on the exams is remembering two things: stations do not have to be manned, and anything over 50 kilometers is "space".

Monday, August 16, 2010

Harmful interference

T1A04: Which of the following meets the FCC definition of harmful interference?

  1. Radio transmissions that annoy users of a repeater
  2. Unwanted radio transmissions that cause costly harm to radio station apparatus
  3. That which seriously degrades, obstructs, or repeatedly interrupts a radio communication service operating in accordance with the Radio Regulations
  4. Static from lightning storms

The correct answer is C–That which seriously degrades, obstructs, or repeatedly interrupts a radio communication service operating in accordance with the Radio Regulations.

(Authority: 97.3(a)(23))

"Harmful interference" is another term from the jargon of radio regulation. Interference, broadly speaking, is anything that tends to disrupt communication, regardless of source. Not all interference is "harmful", though. Merely being "unwanted" or "annoying" is not enough to rise to the level of "harmful"; the disruption has to be significant or repeated, or must completely prevent all communication, before it rises to the level of harmful. Finally, "harmful interference" never originates from a natural source, so static from lightning storms, no matter how annoying or disruptive, doesn't count as harmful interference.

All radio licensees, including amateurs, are prohibited from causing harmful interference with any other station. Stations who are suffering from harmful interference are entitled to relief from that interference, which means that the station causing the harmful interference can be made to stop, by force if necessary, by the governing administration that has authority over that station.

Harmful interference doesn't have to be intentional, although it often is. Jamming (that is, transmitting on top of other transmissions in order to block them) is an especially pernicious form of harmful interference. But that's not the only form of harmful interference; far more common are things like spurious emissions caused by malfunctions or maladjusted transmitters, leakage from cable television systems, and unwanted noise from defective household electronics like computers or televisions. All of these, if severe enough, count as harmful interference that can result in enforcement actions from the FCC.

In practice the FCC's effort to abate harmful interference is proportional to what the licensee suffering the interference pays in licensing fees for their license; since amateurs pay nothing for their licenses the FCC doesn't work terribly hard to resolve interference complaints. Basically that means we have to investigate the circumstances ourselves and wrap the whole thing up nice and pretty so all they have to do is some quick work to verify the complaint before they'll act. Fortunately the ARRL is actually pretty good at this; one of the few things they do do well.

This particular question is one that was improved in this version of the question pool; in the 2006 question pool the question misstated the definition of "harmful interference", leading me to complain about it when I blogged about it about a year ago.

Part 97 of how many?

T1A03: Which part of the FCC rules contains the rules and regulations governing the Amateur Radio Service?

  1. Part 73
  2. Part 95
  3. Part 90
  4. Part 97

The correct answer is D–Part 97.

The FCC, as I mentioned in the previous post, regulates all nonfederal use of radio for communication in the United States. In the course of doing this it issues lots and lots of regulations. These are gathered together (along with selected regulations from certain other agencies) in Title 47 of the Code of Federal Regulations. For bureaucratic reasons, the regulations are divided into numbered "parts"; the FCC is allotted parts 0 through 199. The first twenty parts (0-19) are for administrative and general rules that apply to the FCC and its licensees generally. The remaining parts, 20 through 101, are rules for different types of licensed radio uses, or "services", as they are known in radio regulatory jargon.

The four answers the NCVEC offers for this question are therefore all rules for specific radio services. Part 73 contains the rules for the broadcast media services, including AM and FM radio, television, and the international broadcast service (shortwave). Part 90 contains all the rules for what is known as the "private land mobile" service; this rather large division includes business radio and public safety radio (such as police and fire services). Part 95 covers the "personal radio" services such as CB and GMRS. And, finally, Part 97, the correct answer, covers the amateur radio service. It's generally a good idea for hams to have a copy (at least in electronic form) of Part 97 simply because the FCC expects us to be aware of the rules of the service.

The astute reader will already have noticed that when I quote the questions in these posts, there is often an "authority" section at the bottom of the question (although not in this post, because the NCVEC didn't provide an authority for this question). These are references, provided by the NCVEC, to the portion of the FCC regulations that the question under discussion is testing. These references are hotlinked to the Government Printing Office's Electronic Code of Federal Regulations Service, which is updated daily and is therefore the most up-to-date and official source for these documents (even more so than the FCC itself). There are other sources for Part 97 out there, but if you use a source other than the GPO, please ensure that the source you use is up-to-date; the FCC has amended Part 97 twice already this year alone.

What does the FCC have to do with amateur radio?

T1A02: What agency regulates and enforces the rules for the Amateur Radio Service in the United States?

  1. FEMA
  2. The ITU
  3. The FCC
  4. Homeland Security

The correct answer is C–The FCC.

(Authority: 97.1)

This is another question that's in the question pool to ensure that aspiring licensees are educated about something that is very important to know: that amateur radio, in the United States, at least, is regulated by the Federal Communications Commission, or FCC, and not by any other entity.

The FCC has been charged since its creation in 1934 with the regulation of all uses of radio frequency energy for communication within the terrority of the United States, its coastal waters, and ships at sea sailing under the flag of the United States, except for use by instrumentalities of the federal government itself (over which the FCC has no jurisdiction). Amateur radio falls within this scope, and so amateur radio is regulated by, and the rules for amateur radio written and enforced by, the FCC. 

Two of the other three entities listed are other federal agencies that have no authority over radio: FEMA and Homeland Security. Hams have no specific duties, functions, or responsibilities with respect to either FEMA or Homeland Security. The third entity offered as a distractor is the ITU, or International Telecommunication Union. The ITU, unlike the others, is not a federal agency; it is instead an agency of the United Nations, formed originally in 1865 as the International Telegraph Union in 1865 by a multilateral treaty amongst 20 nations. The United States is a charter member of the ITU and, as a member nation, agrees to abide by the regulations the ITU sets forth regarding radio. However, while the FCC will only rarely write regulations that are inconsistent with those issued by the ITU, it remains the case that it's the FCC regulations, and not the ITU regulations, that apply to amateur radio in the United States. Which is just as well, because the FCC regulations anyone can get for free from the US Government Printing Office, while the ITU regulations are not available without the payment of a fee to the ITU, or more accurately the ITU's publisher.

The FCC isn't the only entity that a ham has to care about. Hams must also follow FAA regulations (when erecting towers over a certain height, as set forth in Part 17). Hams must also be aware of and follow certain regulations of the National Technology and Information Agency (NTIA), issued as part of the latter's authority to coordinate the use of radio by the federal government. Several amateur bands are shared with federal users (including the military) and amateurs must be aware of the NTIA's regulation of those shared bands and observe any restrictions placed by NTIA in the use of those bands. Finally, while FCC regulation preempts state and local regulation of radio with respect to radio frequency interference and radio frequency exposure safety, state and local authorities may still enforce "reasonable" regulations on antenna structures for the purpose of electrical and mechanical safety and other "legitimate" purposes.

In practice, the FCC governs with a relatively light hand. Amateur radio is a tiny tiny piece of the FCC's pie. Amateur radio licensing generates very little revenue for the FCC (as the licenses are free), and they put relatively limited resources into the amateur radio area. In general the FCC expects us to take care of ourselves. This is a mixed blessing: on one hand it means that the FCC isn't something we generally have to deal with much; on the other hand, when there is a problem, getting the FCC to act on it can be difficult. It's not clear to me that a heavier hand would be better for amateur radio, though, and the other alternative (no amateur radio at all) is clearly worse.

Who Is Amateur Radio For?

This is the first post in what is likely to be a long series that discuss the material on the Amateur Radio licensing examinations. Each post will typically focus on one question from the question pools; there are thousands of these questions so this will probably go on for some time. Some of this material will likely be repetitive with prior posts in this blog, but I will try to make it interesting nonetheless.

T1A01: For whom is the Amateur Radio Service intended?

  1. Persons who have messages to broadcast to the public
  2. Persons who need communications for the activities of their immediate family members, relatives and friends
  3. Persons who need two-way communications for personal reasons
  4. Persons who are interested in radio technique solely with a personal aim and without pecuniary interest

The correct answer is D–Persons who are interested in radio technique solely with a personal aim and without pecuniary interest.

(Authority: 97.3(a)(4))

This question's presence in the Technician pool acts to ensure that people who are setting out to become hams will understand both what amateur radio is and also what it is not. Amateur radio is not (as is widely believed, if you believe the random noise I hear on Twitter and Backtype) a means by which one can broadcast one's opinions to myriads of rapt listeners. Nor is it intended as a personal communication service (either with your friends and family, or as a general chat service); people looking to do that should consider whether one of the Personal Radio services, or even a cell phone, would better serve their needs. Amateur radio is intended to allow those who have an interest in radio for its own sake a means to explore and develop their interest. If you are hoping to accomplish something useful, and you're just considering using radio as a means to do that, amateur radio may not be what you're looking for. Especially if the thing you're hoping to accomplish involves making money for yourself or someone else: that's specifically prohibited.

As it happens, the foregoing notwithstanding, there's quite a lot of use of amateur frequencies for what amounts to the broadcasting of opinion (as anyone who has listened to 75 meter phone, or to far too many VHF repeaters, can attest), and it's certainly common to see amateur radio used for personal communication between family members, or for general chatting (the latter is often called "ragchewing"). It's just that these are not part of the principle purposes of the amateur radio service, and the FCC offers other services which are explicitly intended for these purposes.

Fundamentally, if you think the whole concept of flinging signals through the air and catching them halfway across the world (or just halfway down the street) is really awesome and want to play with this more, and are willing to take quite a bit of time to learn some pretty complicated stuff, then ham radio is for you. If you just want to talk to people halfway around the world (or, again, halfway down the street), well, may I suggest Twitter? It's a lot easier to get on Twitter than it is to get a ham radio license, after all, and you don't have to buy nearly as much equipment. Fundamentally, ham radio is a geek thing; if you don't have the knack, then it might well not be for you.