Basically, it is a form of voluntary participation in an organized program intended to keep interference between repeaters and their users to a minimum. To do this, repeater sponsors work with their local frequency coordinator (FC) who maintains a database of repeater frequencies in active use (as well as new repeaters which are under construction but may not yet be in operation). The FC recommends repeater operating frequencies (and perhaps other technical details) which will, hopefully, be compatible with other existing repeaters.
An Amateur Radio frequency coordinator is, first, a volunteer. He may be a single individual or an organization of volunteers who are recognized by the Amateur Radio community they serve as their "coordinator". He/they might participate in the program because they are interested in either the technical or the political aspects of coordination, but they all do it as a way of putting something back into Amateur Radio. These days, no coordinator worth his salt is in it for the ego! It's too much work! But all coordinators do get some form of self-satisfaction out of doing the job, or they wouldn't bother.
In a nutshell, everyone does. Sponsors of existing coordinated repeaters are assured that the FC will attempt to protect their repeaters and their users from interference caused by new repeaters. Likewise, sponsors of proposed new machines will get knowledgeable assistance from the FC in selecting frequencies for their machines, so that they and their users can feel confident that their new operation will not adversely affect any existing repeaters, and they should experience little interference on their new machines.
In order to make a recommendation, the FC needs some data about the proposed new repeater, such as its location, antenna height, and transmit power. These items all affect, to one degree or another, the repeater's area of coverage. The FC will review the data on the new repeater, then in conjunction with the data in his data-base, he will try to find an optimum frequency pair. Most frequency coordinators will consult with the sponsors of nearby co-channel (same frequency) and adjacent-channel repeaters, and frequently with his adjacent-area counterparts, to make sure there are not any valid objections to the new repeater. This way, sponsors of existing repeaters are given the opportunity to look out for their own interests. Once a new coordination is issued, there is usually a limited construction period (usually six months or so) to get the new machine on the air. If it's not on, or close to it, after this deadline, the coordination is subject to cancellation. This keeps the coordinator's data-base from filling up with "paper" repeaters.
No. Participation in a frequency coordination program is strictly voluntary. No Amateur Radio frequency coordinator has any "authority" to tell a repeater sponsor what he can, or cannot, do. However, the FCC has recognized that participation in a frequency coordination program by repeater sponsors is in the best interests of all Amateurs. Therefore, FCC rules have been adopted which state that the sponsor of an un-coordinated repeater bears the primary responsibility for curing any interference between his repeater and another repeater which is coordinated. Likewise, the sponsor of an un-coordinated machine cannot expect much help from his area FC.
There are two primary reasons for cancellation of a coordination.
Some coordinators require sponsors to file periodic up-dates in order to retain their coordinations. Others rely on their own monitoring efforts to keep abreast of activity.
Yes. In addition to repeaters, the FC also coordinates other operations associated with repeaters, such as radio remote-control frequencies, links between a repeater's remote receivers and the main site, etc. In addition, they also coordinate "remote-base" operations. They can also assist in your understanding of the many inter-related FCC rules that apply to repeaters, remote-bases, links, remote control, auto-patches, cross-band operation, and so forth.
Nowadays there are probably 2 main problem areas.
In many areas frequency coordinators have set aside specific frequency pairs for temporary, portable, or emergency repeater operations. These frequencies should be considered first when setting up a temporary operation such as a parade or other public event, an emergency operation or a short-term experiment.
'There is unfortunately, a small number of uninformed operators who abuse cross-band repeater capabilities causing unintentional, sometimes even malicious, interference. Other problems are caused when the FC is not apprised of changes to existing repeaters, changes of sponsor's mailing address, etc.
Many coordinators are involved in "band-planning" or "spectrum management" efforts, often in association with adjacent-area coordinators, other special-interest groups, or the ARRL's Spectrum Management Committee, Digital Advisory Committee, and Membership Services Committee. Different special-interest groups include the packet community, the DX Cluster community, weak-signal/SSB/CW interests, FM simplex users, ATV'ers, etc. All of these other interest groups need to be considered when "band-plans" are being developed or revised, so frequency coordinators need to keep them in mind as they conduct their spectrum management effort. Band-planning/spectrum management cannot be done in a vacuum! Good familiarity with the FCC Rules is helpful here, since repeater, remote-control, link and remote-base operation is prohibited in some parts of the Amateur HF, VHF and UHF bands.
Many coordinators maintain a list of technical experts who are available to assist repeater sponsors in resolving technical problems. They also maintain a list of Amateurs with the capability and expertise in finding interference sources, both from spurious emissions, as well as malicious interference. Also many coordinators maintain, or have access to, a fairly extensive library of technical information on equipment, system designs, and maintenance. These resources are all available to the sponsors of all coordinated repeaters in the area.
The States of Maryland and Delaware, the District of Columbia, northern Virginia, and the eastern panhandle of West Virginia, are coordinated by The Middle Atlantic FM and Repeater Council, Inc. (T-MARC), an organization which has been providing coordination services for over 20 years. T-MARC's Frequency Coordinating Committee, which is chaired by the T-MARC Vice-President for Technical Affairs, is a group of hams (like yourself) which meets monthly to discuss the month's business and to arrive at a consensus on each coordination or related item on the meeting agenda. They may be repeater sponsors, or members of clubs which sponsor repeaters - but all of them serve "at large" - not as representatives of their repeater or club. Membership is open to any interested Amateur, and we would be pleased to have more active members from the "outer" areas of T-MARC. All of the committee's correspondence is handled by its corresponding secretary, who generates the agenda for each monthly committee meeting.
Committee members all perform some form of monitoring of activity in their areas, so we keep fairly well tuned to what's going on without having to bother system sponsors for periodic up-dates. In the T-MARC area, the busiest place is the 2-Meter band in the greater Washington-Baltimore area. We have a computer-driven scanner which continuously records the activity level on each 2-Meter repeater frequency. This data helps in making frequency recommendations for new machines. But it's getting tougher and tougher, as 2-Meters is really overflowing! Well, there you have it. T-MARC wishes to invite anyone interested in participating in any of its coordinating committee's activities to join in. Additionally, any repeater sponsor or any interested Amateur Radio operator is welcome to come and visit any of the monthly committee meetings to see how it works.