ARRL

Chapter Eight: Operation of the Digital System

Chapter Eight: Operation of the Digital System

 

8.1 HF Digital NTS Operations

 

Radiogram-formatted NTS traffic on HF is being handled by digital means on the so-called "APlink system." This system is a group of mailbox, store-and-forward (MBO) station operators spanning the country. Many of these stations have the capability of receiving and sending traffic via several digital modes including packet, by HF and VHF, all interchangeably. For example, a message received on HF Clover can be forwarded via VHF packet without modification. This flexibility is one of the system's assets as it allows for forwarding along the best path at the time, resulting in the highest efficiency and reliability.

The chief concerns of the digital system, of course, are responsibility and accountability -- most MBO system operators are not concerned about NTS traffic that passes through their systems. Radiograms arriving at their stations are occasionally passed out the VHF port into the packet forwarding system with no guarantee that they will get to their destination. Many of these messages end up in the infamous "black hole" or "bit bucket." Naturally, this violates the most basic principle of NTS: getting the message through all the way, from originator to addressee.

What's the answer? The solution is to introduce responsibility and accountability into the mix, just like we do with traditional NTS nets and operators.

Interested MBO system operators are now certified as "NTS Digital Relay Stations" and as such, they accept responsibility for relaying traffic only to other NTS Digital Relay Stations or NTS-approved nets or nodes. They are appointed by, and are accountable to, their Area Digital Coordinator, who is elected by the Area Staffs and who serves as an NTS Official and official member of the Area Staff. The ADCs maintain and publish a roster of these stations and report their activity to HQ. This way, the traffic stays "in the family," giving it the best chance for proper delivery.

The network of NTS-approved HF Digital Relay Stations is a mighty tool that, when used properly, can provide support to the traditional NTS nets, at any level. The digital network can pick up and move traffic when normal NTS nets cannot, due, for example, to an overloading situation, or lack of normal liaison operators.

 

8.2 VHF Packet Radio Bulletin Boards

 

NTS can take advantage of local packet radio bulletin boards for their ability in buttressing Local and Section NTS Nets and getting channels closer to traffic origination and destination points. Again, however, the concern is that traffic might end up in a "black hole."  Fortunately, many Section Traffic Managers have recognized this potential problem, and are working to ensure that packet BBSs (PBBS) are being cleared of radiogram NTS traffic each day.

Some STMs have found it extremely effective to appoint "Net" Managers to manage the NTS element of these PBBSs. "Net" members, including Official Relay Stations specializing in packet traffic handling, ensure that traffic is forwarded properly, or remove traffic from the boards and either deliver it or bring it to Section- and Local-level NTS nets for handling.

Some STMs have gone so far as to affiliate a major PBBS as an NTS Local or Section "Net." If every Section were as vigilant, packet would be a more reliable resource for moving traffic expeditiously, and with accountability.