The NET Concept

If one thinks about it, the notion of Short Wave Radio as an Internet Replacement is actually somewhat backward.  In reality, the Internet is more of a replacement of Short Wave Radio!

The conceptual structure of the Internet existed many decades, via Ham Radio, before the Internet was ever envisaged.  For example, the passing of an email from one Internet Node to another until it eventually reaches the mail box of the addressee was implemented with Ham Radio when the only radio transmitter consisted of a machine that made sparks which generated "radio waves."  The concept of the Internet Router is the concept of the Ham Radio NET.  As with the Internet, the concept and implementation of Nets is key to a reliable and systematic method of moving information from one place to another.

In it's most basic, and most common form, the Ham Radio NET can be visualized as depicted as in Figure 3.

Figure 3

Every Formal Net has a few things in common:

• There is always a Net Control Station

• The Net meets regularly at a specific time and frequency, whether once every day or once a week

• The Net has a specific purpose

  • Passing Formal Message Traffic

  • Buying and selling equipment

  • Facilitating contact between stations

  • any number of other reasons

There are also many informal Nets which meet at a specific time and frequency; but do not have a Net Control Station, and are formed mostly for a social purpose.  Here station operators simply "chat" among themselves about any number of subjects that come up.

In this lesson we are concerned with the Formal Net which meets for the purpose of passing Formal Message Traffic.  Such a Net is depicted in Figure 3.

The central figure in a Formal Net is the Net Control Station.  The responsibilities of the Net Control Station include:

• Starting the Net at the proper time and on the proper frequency

• Recognizing and recording the stations that "check in" to the net

• Recording the number and destinations of any messages each station wishes to pass

• Facilitating the communications between the station wishing to send a message and the station which is to receive the message (such a station will usually relay the message to yet another station on yet another Net).

• Maintaining strict order among the stations on the Net

• Closing the Net when all business is completed

In Figure 3, Radio Station 2 has a message directly for Radio Station 5.   At some point the Net Control Station will direct Station 2 to pass the message to Station 5.  Depending on the Net, the Net Control Station may direct the two Stations to make contact with one another on the Net frequency and pass the message.   Likewise, the Net Control Station may direct the two stations to make contact and pass the message on some frequency other than the Net frequency, so that the Net business can continue while the message is being passed.  This is at the discretion of the Net Control Station.

Again, in Figure 3, the Net Control Station cannot hear Station 6; so Station 3 acts as a relay between the Net Control Station and Station 6.  Station 6 has a message which must be passed on another Net, so the Net Control directs Station 3 to relay Station 6's message to the Liaison Station, number 4.  After the close of this Net, Station 4 will check-in to the proper Net to pass the message which originated at Station 6 on to yet another station who is able to move the message closer to it's ultimate destination.

Formal Nets can utilize any mode (CW, AM, FM, SSB, RTTY, and one form of AMTOR) which allow multiple stations to communicate with one another.  Some modes, such as PACKET are designed such that only two stations can communicate at any point in time.  For this reason such modes aren't used for this kind of Net.

Such modes as PACKET, however, are used extensively for passing Formal Message Traffic through sort of an automated always-in-session "Net" which I refer to as a Bulletin Board.  A Ham Radio Bulletin Board is very much like you find at http://groups.yahoo.com/group/tt-radio.   At this URL you will find messages, information, and even some Ham Radio related software to download.  A Ham Radio Bulletin Board is always available, provides your own individual "email" mailbox, the ability to upload and download files, threaded message boards, and a lot more.  These days a large percentage of "Formal Message Traffic" is received and deposited for relay using the error free digital mode of PACKET on HF, VHF, and UHF frequencies.

While this presentation of the NET Concept is a bit complicated, it is only an introduction to the concepts which are planned.  The detail implementation goal is to emulate the operation of the National Traffic System.   Don't be fooled by the first page of this URL as there are 11 Chapters plus Appendix A.  Because of the importance of proficiency with this material several Lessons will be devoted to the material found here.  In addition, both IRC and actual on-the-air nets are planned to help us hone our skills.  Every member of tt-radio will be expected to act as the Net Control Station many times over the next couple of years.

In addition to the ability to pass formal message traffic, we must likewise become proficient in "tactical" Net operations.  Tactical Nets are specifically tailored for Emergency situations and communications.  Many of the strict formal rules are replaced by a more flexible set of procedures.  This will also be presented and practiced during the next couple of years.

We have much work and also fun ahead of us as communicators.

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