My research topic is network coding.

Definition: Network Coding is a field of information theory and coding theory and is a method of attaining maximum information in a network.

Problem:
In a butterfly network, there are two sources (at the top of the picture),each having information of some value of A and B. There are two destination nodes (at the bottom), which each want to get both A and B. Each edge can carry only a single value.

If we only used routing, then the central would be able to carry A or B, but not both .Suppose we send A through the center; then the left destination would receive A twice and not get B at all. Sending B poses a similar problem because no routing scheme can transmit both A and B simultaneously to both destinations.

Using a simple code, as shown above, we do get both A and B to both destinations simultaneously by sending the exclusive ¨COR of A and B.( in other words, we encode A and B using the formula A+B). The left destination receives A and A+B, and can find B by the concept of OR operation. This is a linear code because the encoding and decoding schemes are linear operations.

Applications:

Bidirectional low energy transmission in wireless sensor networks.

• Cryptography
• Satellite networksĄ­