A dedicated line is a telecommunication line that only serves one specific purpose. The line will go from the main local hub directly to a single location without connecting to any other service. This single location might be a specific computer, telephone, network or user. The purpose of a dedicated line is the creation of an at-call connection to a communication hub that will never have interference from any other user or service. Using a dedicated line is less common today than in previous decades, but they are still common in select cases.
Regardless of the type of communication, the structure of a telecommunications system is generally very similar. Whether it is a telephone call or an Internet connection, the way information is relayed from one area to another is largely based on the same principles. An area is comprised of different hubs that continuously move down into small and smaller versions. There may be a hub for a street, then a neighborhood, then city, county, and so on. While the exact names and structure of these devices change, the overall theory doesn’t.
In this system, one service will share the vast majority of its transmission time with other information. This information will use space in the line, potentially slowing the service’s overall transmission speed. When it reaches one of the hubs, other services may have priority, for any number of reasons, and the service may have to wait in order to be routed to the next hub. These two factors play a very critical role in the speed and viability of any transmitted signal.
By using a dedicated line, a service can avoid these issues. The line will connect to a single location, service or user on one end and a specific point on the other. The endpoint of the line could be a regional hub that bypasses smaller hubs, a dedicated data transmitter or even a different single location, service or user. In any case, the line will not have any branches between its ends, allowing the one service full access.
In the early days of high-speed transmission, the use of a dedicated line was a common way of ensuring that time-sensitive information would arrive on time. As the speed and bandwidth of communication services increased, the use of a dedicated line was rarely necessary. Even with shared traffic, the slowdown of a network-in-use is a fraction of what it was in previous decades.
Even with faster transmission speeds, there are still a few areas that use dedicated lines. In areas such as secure government sites or utility companies, the use of dedicated lines prevents outside interference or eavesdropping on sensitive information. In these cases, the use of a single line is more for security than for its original purpose. In addition, high bandwidth digital transmissions, such as those from a television station, will use a dedicated line to help prevent artifacting and signal degradation.