Abstract: The shifting surfaces from past to present has evolved many changes and brought many challenges as well and the field of communications is the one which has witnessed this changing dynamics the most. Since the influence of the emerging technologies in yielding better performance than the existing , hence it calls for the newer infrastructure , installation to be made for its establishment and henceforth for its working. Such incorporation of the change in the entire layout is not always possible ,especially in case at the network level. Thus in order to optimize the performance of the operating communication systems comprising of the enhanced features of the newer technologies , we need to go with the option of modification of the existing ones as well as from the latest ones so that they will be complementing and supplementing each other. The optical communication due to the advancement of the photonics and terahertz based schemes is providing excellent ground for the nourishment of the next generation communication systems .Now-a-days the optical fiber has proved out to be the most efficient means of communication channel medium, but it does have some limitations. The paper has focussed on getting the solution for these - last mile problems and overcoming the difficulty of getting a reliable link for the communication purpose in areas where installing the fibers is not easy and thereby the incorporation of FSO link.