In the military community, communications among users on a national or worldwide basis.
Note 1: Compared to tactical communications, long-haul communications are characterized by (a) higher levels of users, such as the US National Command Authority, (b) more stringent performance requirements, such as higher quality circuits, (c) longer distances between users, including worldwide distances, (d) higher traffic volumes and densities, (e) larger switches and trunk cross sections, and (f) fixed and recoverable assets.
While the term is used in military most career fields that are in communications such as 3D1X2 - Cyber Transport Systems (the career field has been renamed so many times over the course of many years but essentially it is the same job (Network Infrastructure Tech., Systems Control Technician, and Cyber Transport Systems)) or may work in areas that require the "in between" (cloud networking) for networks (MSPP, ATM, Routers, Switches), phones (VOIP, DS0 - DS4 or higher, and so on), encryption (configuring encryption devices or monitoring), and video support data transfers.
The Military provides an avenue but does not make the individual a master of the career field.
Also at least get an associate degree, over 5 years experience, and all of the required "certs" (Network +, Security +, CCNA, CCNP and so on) to acquire the job or at least an interview.