Books of messages and the processes of booking, unbooking, and rebooking messages are poorly understood. This article explains what books are, why they exist, and when to use them, and how to use them.
What Is A Book of Messages?
A message, sometimes called "single" messages (plural, "singles") on amateur message relay nets, follow a particular structure. The amateur radiogram is the default message structure, made up of critical parts described in ARRL's Methods, Practices, and Guidelines (MPG) Chapter 1, "The ARRL Message Format."
A book is not just a plurality of messages, but two or more messages with one or more parts in common and prepared for transmission to avoid repeated transmission of the common parts.
Consider an example message that we often hear on COTN, an acknowledgement of a session report.
These often come in groups, sometimes going to the same station, sometimes going to different stations. Here's another that might be listed on the same session.
Notice how much the messages have in common:
A book of these two messages is where the two messages are arranged such that the common parts are transmitted first, one time, to both stations, and then each station gets its parts individually transmitted.
Why Use Books?
MPG discussions of sending books in both voice and CW procedure, as a "time saving option" (§§ 2.3.4, 3.3.8). There are minor differences in the text of MPG regarding booking but these are editorial differences, not procedural differences. Because COTN uses voice control and relays by voice or digital with Narrow Band Emergency Messaging Software (NBEMS), I follow the language of voice procedure in this discussion.
Considerable time can be saved in sending two or more messages with fixed parts, such as fixed addressees, fixed texts, etc., by "booking" the messages as they are voiced.
Return to the example above. Transmission of those messages with full procedure at "writing speed" takes approximately 60 seconds. The common parts take about 30 seconds of that time. Transmitting two singles thus takes 120 seconds, where transmitting those same messages as a book of two takes 90 seconds. Especially where books are large (consider a special event's worth of acknowledgements in a book of 15), that time can have a significant impact on the total net operation time.
In other cases, where liaisons are moving messages between nets, fixed schedules place inherent limits on how long nets can run. In busy times, such as emergencies, that kind of difference can have a material impact on how many messages can move on a given cycle of operation. Messages that don't make it through the exchange may thus be delayed by hours or days.
Why Book During Relay
Start with this example of a single.
If we're holding this message for relay, we would list this as a message on COTN as "through, one," which is to say, it is going up to a higher-level net for relay. The message would go to COTN's "Section Net Liaison." That station would take the message and then go to an Ohio Section net, and list the message as "through, one," (voice) or QTC THRU 1 (CW or digital). The Section Net's Eighth Region Net (8RN) liaison would then take the message and then go to 8RN. There it would also be listed as "through," so the 8RN rep to Eastern Area Net (EAN) would take the message, where it would go for further handling.
Imagine now another message making its way through the system at the same time.
Injected into the traffic system in Michigan, the message will follow the routing from Michigan to Connecticut. In this case, Michigan is part of the Eighth Region, where the message will be listed as "through" and the 8RN liaison station to EAN would be directed to take that message.
At the end of that 8RN session, 8RN's liaison to EAN now has two messages that are headed to the same addressee in the Connecticut Section, which is part of the First Region, which is part of the Eastern Area. The scheme of routing and message movement is described in the MPG NTS Routing Tables.
The station holding the messages may now go to EAN and list the traffic for First Region Net (1RN), "First Region, two" (voice) or QTC 1RN 2 (CW). EAN's 1RN rep would then be directed to take the messages, in turn listing them on 1RN as two for Connecticut, and so on until delivery.
The addressee being in common means that the 8RN rep to EAN, 1RN rep to EAN, and CT rep to 1RN will need to transmit exactly the same thing (the addressee) twice, and their recipient will need to receive exactly the same thing twice. If there were a third message headed for the same station at the same time, retransmission would be three times, and so on.
Any operator transmitting these two messages may save time by "booking," i.e., creating a book of the messages with the common addressee.
In the present example, the common parts voiced once at full procedure take about 25 seconds. If the 8RN rep is the first to book the traffic, then that 25 seconds is saved on EAN, 1RN, CT, and any local net used for message movement. Assuming one local net, that's a savings of two minutes. As shown earlier, larger books and books with more parts in common improve efficiency further.
Do Only Originating Operators Book?
No. MPG is clear that booking is done by the sending operator. "Booking is usually done in the head of the sending operator" (§ 184.108.40.206), further suggesting that the book came to the sending operator as singles. The sending operator, having organized the traffic before the start of the net, is prepared to list the traffic as a book, and during transmission can see the messages and make the necessary adjustments mentally to transmit the singles as a book.
This is precisely the case that we illustrate in our example of messages from Ohio and Michigan to Connecticut.
It is incorrect to assert that any operator violates NTS or good amateur procedure to book traffic, and improper to "correct" an operator who does so.
When Should We Use Books?
Booking is optional. Continuing, MPG states that booking "is done at the option of the operators and is not mandatory. The economy of booking is based mainly upon the size of parts that would otherwise have to be repeated." (§ 220.127.116.11)
We see several considerations. Remember the purpose of booking: the procedure is to save time. MPG's discussion of this in the chapter on CW procedure is more helpful. (§ 18.104.22.168)
Booking two messages with only a fixed signature is hardly worth the effort. Booking 12 messages with a fixed 25 word text is another matter. The text would be sent only once.
The decision to book is made based on the amount of time and effort to be saved and the wishes of the stations involved.
Having dealt with the purpose of booking and the level of economy involved in building any particular book, we're left with the consideration of the wishes of the stations involved, i.e., both sending and receiving operators. Again, the CW chapter is clearer: "Booking should not be used if the receiving operator objects." (Ibid.)
A receiving operator objecting to the book need not justify the request to have the traffic sent as singles. Reasons for such a request are local to the receiving station, ranging from operator experience, local site procedure, or the operator's ability to perform the work of rebooking, unbooking, or accounting for the messages.
Just as it is improper to correct a station that books messages, it is incorrect to require that receiving operators take books.
As COTN is a training net, we encourage operators to learn to handle books effectively, which means being able to send and to receive books seamlessly. Books can come in almost any variation and take practice to handle well. That's why we train (to learn how) and why we operate regularly (to get and stay good at using the procedure we've learned).
Learning and Using Books
MPG is the reference for booking. Relevant parts of the MPG are
2.1.4 (Voice Procedures)
2.3.4 (Voice Booking)
3.3.8 (CW Booking)
3.4 (CW Procedures)
4.9.6 (Net Control, Assigning Books)
4.10.10 (Net Control, Dispatching Books)
4.11.4 (Net Control, Dispatching Books to Multiple Stations)
4.12.6 (Net Control, Dispatching Books to Multiple Stations, Off-Net)
8.2.5 (Originating Messages at Public Events)
8.3 (Organizations Originating Book Messages)
COTN is a training net. Operators are always welcome to list books, to book traffic with common parts, to accept books, and to negotiate with other stations on whether to transmit messages as singles or in books.
Becoming an effective traffic handler and the kind of station operator that others want to work with is a matter of following a simple formula. Be kind, be curious, and be disciplined in your operations.