The Role of Coaxial Cable in Broadband Networks

The cable operators, telephone companies, and internet providers use coaxial cables for delivering data, video, and voice communications to customers. This technology is in use since the early 20^th century and it provides reliable communication services.

In broadband communication, the data, voice and video are converged on a single infrastructure for better use of bandwidth.  Usually, optical fiber is used as for transporting the signals over larger distances and coaxial cable is deployed for distributing the signal across the network. Hence, before deploying the coaxial cable, it is very important for engineers to understand its characteristics. In this article, we have explained the basic role of coaxial cable in broadband networks.

RF Transmission

The cables are classified into different categories. The coaxcable falls into "RF-transmission line" category because it can transmit the radio-frequency (RF) signals efficiently. Due to its physical characteristics, it transports the RF signals rather than radiating them. The physical characteristics of this cable depend on the bandwidth; the greater the bandwidth carried by this cable, the more critical the physical characteristics. Hence, it is necessary to properly install the cables and connectors for better performance.

The attenuation of a coaxial cable can be determined by three major factors i.e., resistance, dielectric material, and radiation. The greatest amount of attenuation per unit length in the coaxial cable is produced by the resistance. Resistance depends on the cable materials, frequency of the transported signal, diameter of the conductors, and ambient temperature.

The attenuation is not greatly affected by cable dielectric. The major use of dielectric material is to maintain the spacing between the shield and center conductor. A small amount of signal energy dissipates in the dielectric as this material is not a perfect insulator. For reducing the attenuation in coaxial cable, dielectric materials with better insulating properties can be used.

Almost all the cables face some attenuation due to radiation. It is not possible achieve perfect cable dimensions hence, a small amount of energy leakage can occur due to the symmetry of the cables. However, it is very important that the RF signals do not escape from the coaxial cable otherwise these signals can interrupt with the wireless services.

Moreover, it is very important that the impedance of the transmission medium matches with the impedance of the devices used in the system. If there is a mismatching between the two then it can lead to transmission problems.

The Right Connections

Another challenge is to make the right connections in order to maintain network performance. The connector must be capable of maintaining RF characteristics as well as the characteristic impedance of the cable. The connectors that are used for connecting the rigid coaxial cable are usually a three-piece design. For flexible coaxial cables, usually, F-type connectors are used which is normally a one-piece connector.

Hence, by making the right connections and reducing the losses, rf signals can be transmitted successfully across the broadband networks by using coaxial cable. If you have any question related to the article, please feel free to ask in the comment box below: