Section 17.1. Overview of Data Compression

17.1. Overview of Data Compression

The benefits of data compression in high-speed networks are obvious. Following are those that are especially important for the compressed version of data.

• Less transmission power is required.

• Less communication bandwidth is required.

• System efficiency is increased.

There are, however, certain trade-offs with data compression. For example, the encoding and decoding processes of data compression increase the cost, complexity, and delay of data transmission. Both of the two processes of data compression are required for producing multimedia networking information: compression with loss and compression without loss .

In the first category of data compression, some less valuable or almost similar data must be eliminated permanently. The most notable case of compression with loss is the process of signal sampling. In this category, for example, is voice sampling (Section 17.2). With data compression without data loss, the compressed data can be recovered and converted back to its original form when received. This method of compression is typically applied to digital bits after sampling.

Figure 17.1 shows the basic information process in high-speed communication systems. Any type of "source" data is converted to digital form in a long information-source process. The outcome is the generation of digital words. Words are encoded in the source coding system to result in a compressed form of the data.

Figure 17.1. Overview of information process and compression in multimedia networks