new ccna 200-301 exam fee

new ccna 200-301 exam fee.3.2 Basic Themes 29wider, as shown in Figure 3-9. Obstacles that were not so obvious in Figure 3.8 are more clearly highlighted in Figure 3-9.Figure 3-9 Directional Antenna and LOS with ObstaclesWhen you plan for LOS transmissions, take the nearest obstacle into account.3.2.3 Determining the Impact of Signal Strength Although deploying a network that can withstand all kinds of interference may seem hopeless, you can go about reversing the adverse situation. To do this, you need to know what tools to use in the transmission path to determine signal wavelengths, noise levels, and potential sources of interference. This section will discuss these tools.1. Fresnel districtFirst, a little background information. Augustin-Jean Fresnel (1788-1827) was a French physicist and civil engineer. He correctly predicted that light travels in transverse waveforms. He was correct in this assumption or rather assertion. As a result of his findings, a method of determining where reflections would cause in-phase and out-of-phase between the sending and receiving ends was named after him. This method of determination is known as Fresnelzone ( Fresnel).This was Fresnel's method of working. First he divided the path into zones. The first zone should be free of obstacles for at least 60% of its area. To visualize it more, you can imagine the shape of a rugby ball, which is wider in the middle. However, using the Fresnel zone calculation, you can use a formula to determine the size of the middle of the ball. This helps you determine the width of the wave that will be sent to be sure there are no obstacles in that path.Note: Although the CCNA wireless exam does not require the calculation of the Fresnel zone. But you can find it at http://en.wikipedia.org/wiki/FresneLzone#Determining_Fresnel_zone_clearance website to see this formula. Similarly, you can find the Fresnelzone clearance ( clearance) calculator° at http://www.terabeam.com/support/calculations/fresnel-zone.php