What is Bandwidth?

Often when describing electronic communication networks, the term "bandwidth" is used. This is one of the key characteristics of such systems. At first glance, it may seem that a person whose work is not connected with communication lines, there is no need to understand what the bandwidth of the channel is. In fact, everything is a little different. Many have a home personal computer connected to the global Internet. And everyone knows that sometimes work with the "World Wide Web" slows for no apparent reason. One of the reasons for this is that at that very moment the bandwidth of the provider's channel is congested. The result is an obvious slowdown and possible malfunctions. Before we define the notion of "bandwidth," let us use an example that allows any person to understand what is at stake.

Imagine an automobile road in a small provincial town and in a densely populated metropolis. In the first case, most often it is designed for one or two streams of machines, respectively, the width is small. But in large cities, even with a four-lane movement, you will not surprise anyone. At the same time, the number of cars traveling the same distance along these two roads is significantly different. It depends on two characteristics - the speed of movement and the number of bands. In this example, a road is a communication channel, and machines are bits of information. In turn, each band is a communication line.

In other words, the bandwidth indirectly indicates how much data can be transmitted over a communication channel per unit of time. The higher this parameter, the more comfortable it is to work through such a connection.

If the transmission rate is obvious (it increases with decreasing signal transmission delays), the term "bandwidth" is a bit more complicated. As you know, so that the signal can transmit information, it is transformed in a certain way. With respect to electronics, this can be frequency, amplitude or mixed modulation. However, one of the features of the transmission is that several pulses with different frequencies (within the common band, while the distortions are within the permissible limits) can be transmitted simultaneously on the same conductor simultaneously. This capability allows to increase the overall performance of the communication line without changing the delay. A vivid example of coexistence of frequencies is the simultaneous conversation of several people with different timbres. Although they say everything, but everyone's words are quite distinct.

Why is there sometimes a slowdown when working with the network? All is explained quite simply:

- the higher the delay, the slower the speed. Any interference to signal transmission (software or physical) reduces the performance;

- often the data stream includes additional bits that perform duplicate functions - the so-called "redundancy". This is necessary to ensure operability in the presence of interference on the line;

- the physical limit of the conductive medium is reached, when all allowed frequency bands are already used and with new pieces of data they are placed in the queue for sending.

To solve such problems, providers apply several different approaches. This can be virtualization, which increases the "width", but introduces additional delays; Increase of the channel due to "superfluous" conducting media, etc.

In digital technology, the term "baud" is sometimes used. In fact, it means the number of bits of data transferred per unit of time. In the times of slow dial-ups, 1 baud corresponded to 1 bit per 1 second. In the future, with increasing speeds, "baud" ceased to be universal. It could mean 1, 2, 3 or more bits per second, which required separate instructions, so at the moment another system is used that everyone understands.