Why do signals bounceSolutionSignal bounce occurs when signa

Why do signals bounce?

Solution

Signal bounce occurs when signal is transmitted down a line, teaches a destination, and gets reflected back to its source signal bounce is highly undesirable in a network of computers since the bounced signal can interface with other signal. One network topology is the bus, where all computers are connected to a single main line, or bus. There are several different causes to signal bounce on a bus network.

At either end of the bus, there must be a terminating resistor that absorbs the signal so that it cannot bounce. It is, instead dissipated as heat through the resistor. If both ends of the bus lack a terminating resistor, signal bounce will occur. The terminatiing resistor must match the impedance load of the transmission line to prevent signal bounce. For computer networks, this is 50 Ohms. The term \"Ohms\" refers to a physical measurement of resistance to electrical current.

The terminating resistor must absorb all of the energy of the transmitted signal to avoid signal bounce. This occurs when the impedance of the terrminating resistor matches that of the transmission line or bus, Luckily, networking equipment is standardized so finding an improper terminating resistor is unlikely. However, a malfunctioning terminating resistor may behave outside of its nominal spedifications and therefore behave like an improper terminating resistor. If a terminating resistor does not measure an impedance of 50 Ohms at the frequency that the network operates at, it may cause signal bounce.

Network cabling is rated at a maximum frequency at which it can transmit data. Exceeding this frequency can alter the electrical characteristics of the netwoek, and thus, necessitate the need for non-standard terminating resistors to absorb signals.It is often easier to replace the cabling with the appropriate kind than attempt to track down a non standard electrical component of any sort.

A fault in the network, such as a malfunctioning network port, can cause signal bounce. The reason for this is that network ports themselves behave like rerminating resistors. If they malfunction, then they may reflect the entire signal back down the bus.