Calculating signal propagation delay and throughput (Solution) PDF

Preview

Summary

Calculating signal propagation delay and throughput (Solution)...

Description

Calculating signal propagation delay and throughput How to calculate the signal propagation delay if we know the speed of propagation and the distance? 𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝 𝑝𝑝𝑝𝑝𝑝=𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝 / 𝑝𝑝𝑝𝑝𝑝 𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝 To be able to use this formula you need to express the distance in meters and speed of signal propagation in meters per second (m/s or mps). Speed of propagation is different for different materials, for example, speed of sound through air is 340.29 m/s. Remember, you see the lightning before you hear the thunder because the light travels much faster than sound. In this course we will use only two speeds for any guided propagation (copper, fiber optical cable) we will assume the propagation speed of �×��� m/s and for any unguided propagation (radio, infra-red light and other wireless methods) the speed of light is �×��� m/s. How to calculate the throughput of a link? Example: Calculating propagation delay of a connection. Example: Two cities are connected with an optical cable. The cable is 3,247 km long, determine the propagation delay. 3,247 km = 3.247×106 m If we define 𝑝 to be the delay than, 𝑝=3.247∗106/ 2∗108 s or 𝑝=0.016235 s or 𝑝=16.235 ms. Exercises: 1. A coaxial copper cable is used to create a link between Sydney to Canberra covering the distance of 300 km. What is the propagation delay on this link? Distance = 300∗103𝑝 𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝 𝑝𝑝𝑝𝑝𝑝=3∗105 / 2∗108=0.0015 𝑝 2. A caller from Sydney is talking with her brother in New York over the phone line. What is the minimum signal propagation delay assuming the guided propagation and the distance of 12,000 km? Distance = 12,000∗103𝑝 𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝 𝑝𝑝𝑝𝑝𝑝= 12∗106 / 2∗108=0.06 𝑝 3. A connection between two countries consists of the two links in sequence. The first link is 386 km long optical fiber cable and the second link 797 km long radio link. What is the minimum signal propagation delay on this connection? Distance 1 = 386∗103𝑝, Distance 2 = 797∗103𝑝 𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝 𝑝𝑝𝑝𝑝𝑝= 386∗103 / 2∗108 +797∗103 / 3∗108=0.0019+0.0027=0.0046 𝑝...