February 23, 2013

Networks of Amateur Radio (Ham) Stations

In order to provide reliable radio communications during emergencies, some type of organization must occur between amateur radio operators who are providing the temporary communication. That is, hams must know when to transmit and when to receive. They must behave as radio operators and not as personnel providing relief, that is, they provide communications to relief agencies and people but do not participate in the decision making processes used by those people. They relay messages as they receive them and do not second-guess the content of the messages.

In order to provide the coordination and reliable operation of their equipment, hams are often organized into networks or nets that have particular protocols that the hams follow in providing temporary communications. This page gives a brief overview of amateur radio nets.

Types of Nets

There are two types of nets that are used by ham operators: directed nets and open nets. Directed nets have Net Control stations (NCS) that begin and end the net operations. Open nets may have NCS, but they frequently don't have them due to the informality of the nets. The two nets may have different protocols that are used while the nets are in operation.

 Directed Nets

In directed nets, hams may only initiate initial contact with the NCS because the NCS has full control over the stations participating in the net. Subsequent contacts between stations will be directed or controlled by NCS. For example, suppose one station has a message for another station. That station will notify the NCS that he/she has a message for so-and-so. The NCS will decide if the two stations may conduct their business on the net frequency or if they should go to an alternate frequency, and the NCS will direct the two stations accordingly.  Directed Nets are useful with nets that have a lot of business to conduct or nets that have a lot of hams checking in.

Open Nets

In open nets, once the net is in operation, any station may call any other station without going through NCS, and the two stations make their own decision about going to an alternate simplex frequency. Open nets are useful when there is not a lot of business going on in a net and when informality is appropriate.

Round Tables

Round tables are informal groups in which several hams talk among themselves, and each ham has his or her turn to talk. Because they are informal, no station is designated as NCS. Courtesy is needed in all aspects of amateur radio, but it is especially needed in Round Tables.

Purpose of Nets

Nets can be organized specifically for the passing of messages or traffic, or they can be organized for training purposes, or for chatting among friends. A net is just a group of people who meet together to talk with each other via amateur radio. The degree of formality depends on the purpose of the net.

Net Manager

One person is usually designated as the manager of the net. That person has overall responsibility for the operation of the net, including the protocol used in the net.

Net Control Station

The person designated as NCS for a particular session of a formal net will open and close the net. He or she may read from a prepared paper about the net meeting for such and such a purpose on such and such days of the week (or month) and at such and such a time. That dialog may give the frequencies used by the net and tell how people should contact the NCS. It is recommended that persons not members of a net listen to the net for a few minutes to understand the degree of formality used in the net.

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