Communication basics

Bit rate and baud rate

The bit rate is the number of bits that can be transmitted serially per second. The baud rate is the number of times the signal changes per second. The relationship between the bit rate and baud rate is:
Bit rate = Baud rate x Number of bits encoded on each signal.

Bandwidth

Bandwidth is the maximum amount of bits that can be transferred at one time. Bandwidth is proportionate to the bit rate as the more bits that can be transferred at one time, the more bits can be transmitted in a second. It is often described using the analogy that bandwidth is the width of a pipe carrying data. The wider the pipe the more data can flow at one time.

Latency

Latency is the time it takes between a signal being transmitted and received. You may have seen a live news report with a satellite link up where the person being interviewed seems to take a long time to answer the questions put to them due to latency. It takes that long for the question to arrive at their end.

Protocols

Protocols are agreed sets of rules on how devices communicate. There are protocols for most aspects of networking e.g. the cables, transmission methods etc. By using agreed protocols networks can be built with parts from different suppliers. We will be learning ore about network protocols later in this unit.

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