Learning Unit 7
Introduction to the National Traffic System (NTS)
Objectives:
This Learning Unit is designed to offer a basic understanding of NTS
and its function during an emergency. When completed, you should understand
how messages are passed from one location to another, and which nets are involved.
You should also know how the NTS system is designed to facilitate the timely
and orderly flow of messages.
Student Preparation Required:
None
Information:
What is the NTS?
The National Traffic System (NTS) is a unique system for handling messages
that was designed over 50 years ago. Its goal is to enable a message to be passed
across the continent within 24 hours. NTS does this with a group of specialized
nets operating in a "cycle" that allows messages to move smoothly from a local
net, to a regional net, to various transcontinental nets, and then back down
to regional and local nets at the destination. Ultimately, someone in a local
net near the addressee should be able to deliver the message by phone, in person,
by mail, or email.
One of the most important features of the NTS is the "system concept." No NTS net is an independent entity that function without interacting with other NTS nets. Each net performs a specific function in the overall organization. To the extent a net fails to perform any of its functions, it can affect the performance of the overall system. (A net whose exclusive purpose is to pass messages between the its own stations would not be considered part of NTS.)
In the days before inexpensive long distance telephone, and well before the Internet and e-mail, the NTS was used heavily for routine daily communication between hams, family, and friends. This daily traffic kept NTS members in practice for handling large volumes of traffic during emergencies and disasters, the ultimate reason for the NTS's existence. Today, routine daily traffic on the NTS is light, and large-scale emergency operations are generally during major disasters with widespread infrastructure damage. However, this does not lessen the importance of the NTS in assisting our served agencies.
The NTS is not part of ARES, but is a separate and distinct ARRL program. The NTS and ARES work together. Think of the NTS as a "long distance carrier", and of ARES as the "local exchange carrier". This analogy is not perfect, but it is close.
The NTS is not intended as competition for the many independently organized traffic networks. When necessitated by overload or lack of outlet for traffic, the facilities of such networks can function as alternate traffic routings where this is indicated in the best interest of efficient message relay and/or delivery.
Nets may sometimes find it necessary and expedient to adopt temporary measures to ensure the movement of traffic. This is considered improper operation only when no attempt is made to return to the normal schedule. Nevertheless, improper operation of any NTS net is the concern of all NTS nets, and every effort should be made to assist in returning any non-functioning or improperly functioning net to its normal operation.
How The NTS Works
The National Traffic System consists of four different levels of nets.
These operate in an orderly time sequence to move messages in a definite pattern
from origin to destination. A message flows through the NTS in a manner similar
to a businessman who travels between two small rural towns at opposite ends
of the country. He has to change carriers many times in the process, starting
with a drive to the local airport, then a feeder airline to a major airport,
to a transcontinental airline, to another feeder airline, and finally by ground
again to his destination. In a very similar manner, the transcontinental message
starts with the originating station in a local net, is carried up to the "Section" net,
then up to the "Region" net, then up to the "Area" net,
across to another "Area" net, and then back down the line to the
point of delivery.
Of course, the message, like the passenger, can "get on" or "get off" at any point if that is the origin or destination. Thus, a message from San Francisco to Los Angeles would not go beyond Region level, and one from Syracuse to Buffalo would remain in the Section net(s). At the local level, messages may be passed into or out of local ARES or other nets for delivery to served agencies, or may be delivered to private citizens directly.
NTS nets may use FM, SSB, or CW, and messages may also be passed through NTS-affiliated local and Section traffic nodes that employ digital modes such as AMTOR and packet, with store-and-forward capabilities and bulletin-board operations. Long hauls can be made by the NTS digital stations on HF that interface with Section traffic nodes and the traditional nets of the system.
Local Nets
"Local" NTS nets are those that cover small areas such as a town, city,
county or metropolitan area, but not a complete ARRL Section. They usually operate
on two meter FM at times and on days most convenient to their members. Other
nets are designated as "emergency" (ARES) nets that do not specialize
in routine traffic handling. These nets generally become active only for training
and during emergencies.
Local nets are intended mainly for local delivery of traffic, with a goal of delivery by non-toll telephone calls. They provide outlets for locally originated traffic, and route the incoming traffic as close as possible to its actual destination before delivery.
A local net, or "node," may also be conducted on a local packet BBS, where messages may be stored, forwarded and picked up by local operators for subsequent delivery. A Net (Node) Manager is appointed by the Section Traffic Manager to manage these functions, and assure that traffic is moved expeditiously.
Section Nets
The purpose of the "Section" net is to handle messages within the Section,
and to handle messages moving to and from the "Region" nets.
Either liaison stations from local NTS nets and nodes, individual stations, or both, handle messages passing within the Region. In most areas, all stations in the Section are invited to take part. However, in a highly populated Section with several metropolitan areas covered by local nets, representation may be by liaison stations, plus individual stations in cities or towns not covered by local nets.
The Section may have more than one net (e.g. a CW net, a VHF net, an SSB net, or a Section packet BBS). In an area with low population density or NTS activity, two or more Sections may combine to form a single net operating at Section level. Section nets are administered through the office of the Section Manager, with authority for this function often delegated to an appointed Section Traffic Manager and/or designated Net Managers. In the case of combined-Section nets, officials of the Sections concerned should collaborate on the designation of a qualified Amateur to manage the net.
Region Nets
"Region" nets cover a wider area, such as a call area. At this level, the
object is representation of each ARRL Section within the Region. Participants
normally include:
There may be more than one representative from each Section in the Region net, but more than two are usually superfluous and will only clutter the net. However, all Section representatives are required to represent the entire Section, not just their own net.
The purpose of the Region net is to exchange traffic between the Sections in the Region, put out-of-Region traffic in the hands of liaison stations, and distribute traffic coming into the Region among the Section net representatives. Region nets are administered by managers appointed by the Field and Educational Services Manager at ARRL Headquarters.
Area Nets
At the top level of NTS nets is the "Area" net. Participation at the area
level includes:
There are three Areas, designated "Eastern", "Central" and "Pacific", the names roughly indicating their coverage of the US and Canada except that the Pacific Area includes the Mountain as well as the Pacific time zones. Managers appointed by the ARRL Field and Educational Services Manager administer the Area nets.
Transcontinental Corps
The handling of higher priority messages between "Area Nets" is accomplished
through the facilities of the TCC. TCC members handle "routine" messages only
in times of extreme overload. This is not a net, but a group of designated liaison
stations that have the responsibility for seeing that inter-Area traffic reaches
its destination Area. TCC is administered by TCC directors, or as delegated
to the Area Digital Coordinator, in each Area who assign stations to report
into Area nets for the purpose of "clearing" inter-Area traffic, and
to keep out-of-net schedules with each other for the purpose of transferring
traffic from one Area to another.
"Hot-Line" Circuits
In certain situations, a large volume of traffic may be moving between two
locations, such as from a large refugee center to a Red Cross office. Rather
than attempting to move these messages through the normal system, a "hot-line"
circuit is established between two or more stations at or near these locations.
This avoids overloading normal nets, and speeds delivery of critical messages.
Increased Operations During Disasters
In day-to-day operation, the National Traffic System passes routine messages
around the country. In its emergency role, the NTS is dedicated to disaster
communication on behalf of ARES. The NTS is capable of expanding its cyclic
operation partially or fully depending on the level of need. The normal cycles
can be expanded to handle an increasing volume of messages with greater speed.
In extreme cases, the cycles can operate continuously. This requires all nets
to be on the air full time, with stations designated for liaison operation replacing
each other as stations are dispatched to the higher or lower nets with which
they make liaison.
Activation for Disasters
Emergency Coordinators in disaster areas consult with served agencies to
determine which communication resources will need to be activated.
The Section Emergency Coordinator consults with affected DECs and ECs, and makes an activation recommendation to the Section Traffic Manager, and Section or Regional NTS managers as appropriate. The decision to alert the NTS Region management may be made by any combination of these officials, depending upon the urgency of the situation.
The scope of the activation will depend on the scope of the disaster. If messages need to be passed only within the Section, then only those nets will be activated. However, if the disaster is widespread and communications are disrupted over a large area, Region or Area nets may be needed. During major disasters, Health and Welfare traffic may increase to the point where the TCC needs to become involved.
Managers of NTS nets at local, Section, Region, and Area levels are directly responsible for activation of their nets at the request of ARES or NTS officials. Each EC is directly responsible for activating their local ARES nets.
NTS Alerting Plan
Section Traffic Manager (STM) and Section Net Manager Roles: During a disaster, the STM and certain Section net managers may be contacted by the Section Emergency Coordinator to activate needed Section NTS and ARES nets, either to provide Section-wide contact or, in the case of NTS nets, to provide liaison with the nets outside the Section.
The STM and Section net managers make contact with NTS Region net managers in the event that messages connected with the disaster need to cross Section boundaries, and may recommend extraordinary activation of the Region net.
Specific Section net stations are designated to conduct liaison with the NTS Region net, either through another Section net or directly. This is the responsibility of Section officials, not the Region net manager.
Region Net Manager Functions: Should a disaster situation's needs extend beyond the Section level, any one of the Section officials in a Region or a neighboring NTS Region may contact the Region Net Manager. The Region Net Manager should be able to predict such contact based on the circumstances, and should be available to receive their recommendation.
The Region Net Manager makes contact with the NTS Area Net Manager in the event that communications connected with the disaster transcend Region boundaries, recommending extraordinary activation of the Area NTS net.
Area Net Manager Functions
There are only two Area Net Manager appointees for each of the three Areas
in the US, but their function during and after disasters is of paramount importance.
Area net managers maintain a high sensitivity to disasters that extend to or
beyond Region boundaries. When one does, Area Net Managers take the initiative
to alert the Region net manager involved to determine if extraordinary NTS operation
is indicated.
In the event that high precedence inter-Area traffic is involved, the Area net managers contact the two Trans Continental Corps directors in the Area to assist by arranging to pass the traffic directly to other Areas.
The Area Net Managers in the affected Area also contact the other NTS Area Net Managers to discuss the possibility of opening extra net sessions if required to handle the traffic reaching them through NTS inter-Area handling. Under some circumstances, direct representation or "hot lines" may be indicated.
The Area net managers maintain close contact with all Region net managers in the Area and make decisions regarding overall NTS operation in consultation with them.
Transcontinental Corps (TCC)
These NTS officials will be involved only where traffic of a precedence
higher than "routine" is to be handled between NTS Areas, or when extreme overloads
are anticipated. TCC directors are ready to alert TCC members and set up special
out-of-net schedules as required. TCC directors may be called upon by the Area
net manager to set up "hot line" circuits between key cities involved in heavy
traffic flow. TCC directors know which of their TCC stations are located in,
or close to large cities to operate such circuits.
Area Staff Chairmen Responsibilities
The three Area Staff Chairmen administratively oversee the NTS Officials
and their operations above the Section level, and will advise their TCC Directors,
and Area and Region Net Managers when appropriate. Their advice may be based
on information forwarded by ARRL Headquarters. The chairmen maintain a high
sensitivity to disasters and other emergencies that may develop. In a large-scale
disaster, the chairmen should be able to contact one another via the International
Assistance and Traffic Net and/or on other prearranged nets.
General Policy for all NTS Operators
NTS operators should be "self-alerting" to disaster conditions that might
require their services, and should check into their regular net or perform assigned
functions without being specifically called upon. Assignments should be worked
out with the net manager in advance. If the operator cannot answer the question,
"If I hear of a disaster, what should I do?" they should seek an answer through
their Net Manager. It may be as simple as "report into the X Net on X frequency."
If the operator concerned is highly specialized, it might be "report to your TCC director in the X net on X frequency for a special assignment." Such an assignment might be an extra TCC function, or it might be as a functionary in a "hot line" point-to-point circuit needing special abilities or equipment.
Most NTS operators participate for one or two periods a week,
and some are active daily. Although every net member should have a specific
assignment, they must also remain flexible enough to change assignments when
the need arises.
Reference Links:
For more on NTS, see Chapter 7 of The ARRL Operating Manual.
Additional details on ARES and NTS can be found in the Public Service Communications
Manual (see www.arrl.org/FandES/field/pscm/index.html),
The Emergency Coordinator's Manual and The ARRL Net Directory,
all published by the ARRL (available online at: www.arrl.org/catalog/)
For local information, or to learn more about NTS net operation
in your area, contact your Section Manager (SM) (www.arrl.org/field/org/smlist.html)
or Section Traffic Manager (STM).
For a list of ARES and NTS nets operating in your area see The ARRL Net
Directory.
Now click on the Activities button and proceed with the Student Activities, which are required before moving to the Questions (click on the Question button). Upon completion of these Questions, go to the next Learning Unit.