Task B Today's Data communication technology includes high-bandwidth transmission mediums such as optical fiber, which has a bandwidth more than that needed for the average transmission signal. If the bandwidth of a link is greater than the bandwidth needs of the devices connected to it, the bandwidth is wasted and an efficient system maximizes the utilization and minimizes the wastage of the link bandwidth. For maximizing utilization and minimizing wastage of the bandwidth of the link multiple techniques are using by the data communication systems. Write a detailed answer about those techniques of at least four (2) pages which must cover the following. 1. The technique of increasing link efficiency and avoiding bandwidth wastage in the Telephone Network (PSTN). 2. The technique of increasing link efficiency and avoiding bandwidth wastage in the Terriesterial Fiber optic network. 3. The Technique of increasing link efficiency and avoiding bandwidth wastage in Computer Digital Networks. Diagrams and illustrations in the explanation of your answer will be appreciated