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 in no way connected with communication lines does not need to understand what a channel bandwidth is. In fact, everything is a bit wrong. Many have a home personal computer connected to the global Internet. And everyone knows that sometimes work with the World Wide Web slows down for no apparent reason. One of the reasons for this is that at that very moment the bandwidth of the provider's channel is overloaded. The result is a clear slowdown and possible malfunctions. Before defining the concept of “bandwidth”, we will use an example that allows anyone to understand what is at stake.
Imagine a highway 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 cars, respectively, the width is small. But in large cities, even four-lane traffic will not surprise anyone. For the same time, the number of cars driving the same distance along these two roads is significantly different. It depends on two characteristics - speed and number of lanes. In this example, a road is a communication channel, and cars are bits of information. In turn, each strip is a communication line.
In other words, the bandwidth indirectly indicates how much data can be transmitted over the communication channel per unit of time. The higher this parameter, the more comfortable working through such a connection.
If everything is obvious with the transmission speed (it increases with decreasing signal transmission delays), then the term “bandwidth” is a bit more complicated. As you know, so that a signal can transmit information, it is converted in a certain way. In relation to electronics, it can be frequency, amplitude or mixed modulation. However, one of the features of the transmission is that several pulses with different frequencies can be transmitted simultaneously on the same conductor at the same time (within the common band, while the distortions are within acceptable limits). This feature allows you to increase the overall performance of the communication line without changing the delay. A striking example of the coexistence of frequencies is the simultaneous conversation of several people with a different timbre. Although everyone says it, everyone’s words are quite distinguishable.
Why is there a slowdown sometimes when working with a network? Everything is explained quite simply:
- the higher the delay, the lower the speed. Any interference with the signal flow (software or physical) reduces 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 has been reached, when all permissible frequency ranges are already in use and with new pieces of data they are placed in the queue for sending.
To solve such problems, providers use several different approaches. This may be virtualization, increasing the "width", but introducing additional delays; channel increase due to "extra" conductive media, etc.
In digital technology, the term "baud" is sometimes used. In fact, it means the number of bits of data transmitted per unit of time. During times of slow communication lines (dial-up), 1 baud corresponded to 1 bit in 1 second. Subsequently, with increasing speeds, the "baud" ceased to be universal. It could mean 1, 2, 3 or more bits per second, which required a separate indication, therefore, another system is currently being used that everyone understands.