# Information Theory

The basis of Information Technology and Communications (IT&C) is the processing and transmission of information. The theory of information therefore lies at the very heart of most modern IT&C technologies.

C. Shannon |

Information Theory traces its roots back to 1948, when Claude Shannon established the first fundamental limits on transmission, storage and encryption of information.

Just as the laws of physics place limitations on what is physically possible, Information Theory places well-defined limits on what is possible in terms of our everyday use of information. For example, the theory tells us the maximum rates at which information can be transmitted from one place to another. This has important consequences when considering spectrum allocations for wireless data networks for instance. Information Theory also places limits on how well we can compress information without suffering from distortion, which leads to limitations on how much information we can store on a hard disk or CD-ROM.

Shannon's model for communications |

Information Theory has turned out to be much more than pie-in-the-sky theoretical mathematics. Recent developments in coding theory have resulted in practical methods for attaining the limits imposed by information theory. Relating this to the physical world, it is as if someone had invented a practical method for travelling arbitrarily close to the speed of light. The existence and implementation of these practical methods of information transmission have underlined the importance and relevance of Information Theory. We are now in an era when advances in Information Theory are in fact directly driving new technologies.

## Key Research Challenges

One of the key challenges for Information Theory is to determine the fundamental limits of information transmission in networks. Data networks are becoming ubiquitous in practice, yet we still do not fully understand even some of the most simple network topologies from an Information Theoretic point of view. Advances in this area will have far-reaching consequences and would certainly lead to new technologies. Specific projects may include

- Multi-terminal information theory
- Fundamental limits of ad-hoc networks
- Space-time and fading wireless channels
- Optical channels
- Quantum channels
- Distributed data compression
- Coding for satellite, terrestrial wireless and optical channels

## More Information

- InformationTheory.net site promoting Information Theory in Australia
- IEEE Information Theory Society
- A Mathematical Theory of Communication
- Shannon's Collected Works
- Shannon's Bibliography

## Australian Information Theory Researchers

Note: You can search for ACoRN Members using the Member Search facility