I think it should consist of various components such as the physical barriers in which to be formed in the appropriate ways, and applied for the terrane in which they will be applied to or in the areas of need.. barrier's such as border patrol agents, and Intel would operate from watch towers placed in the proper distances apart from one another, yet can still be seen by binoculars from one gaurd tower to the other, and for the entire length and/or distances between one section of towers to the other section. Drones would be essential to the observation duties, and to the security along stretches that are either to rough a terrane to build on or along private stretches of land that property owners would be resisting of any huge structures that would destroy the values of their lands, and the scenic value, and the access points that allow cattle to graze openly etc. However, these owners would have to at least grant a narrow strip of right away in order that patrols can ride the entire strip in order to keep proper surveillance of the area. Razer wire should be deployed in correlation with the towers, along with drones, ground surveillance, and river surveillance. It can be done. We need not try to build some sort of wall that proves to be worthless in 8 years or longer. We must also address the problem that we have inward, and that is the problem that is creating the draw in all of this out of control situation. In each gaurd tower you would have a technical center, and this would have a drone station, sensor monitors, crew quarters etc. In fact these towers may be the answer instead of the wall in many areas of question.