3,183 research outputs found
Binary Systematic Network Coding for Progressive Packet Decoding
We consider binary systematic network codes and investigate their capability
of decoding a source message either in full or in part. We carry out a
probability analysis, derive closed-form expressions for the decoding
probability and show that systematic network coding outperforms conventional
network coding. We also develop an algorithm based on Gaussian elimination that
allows progressive decoding of source packets. Simulation results show that the
proposed decoding algorithm can achieve the theoretical optimal performance.
Furthermore, we demonstrate that systematic network codes equipped with the
proposed algorithm are good candidates for progressive packet recovery owing to
their overall decoding delay characteristics.Comment: Proc. of IEEE ICC 2015 - Communication Theory Symposium, to appea
Resilient Network Coding in the Presence of Byzantine Adversaries
Network coding substantially increases network throughput. But since it involves mixing of information inside the network, a single corrupted packet generated by a malicious node can end up contaminating all the information reaching a
destination, preventing decoding.
This paper introduces distributed polynomial-time rate-optimal network codes that work in the presence of Byzantine nodes. We present algorithms that target adversaries with different attacking capabilities. When the adversary can eavesdrop on all links and jam zO links, our first algorithm achieves a rate of C - 2zO, where C is the network capacity. In contrast, when the adversary has limited eavesdropping capabilities, we provide algorithms that achieve the higher rate of C - zO.
Our algorithms attain the optimal rate given the strength of the adversary. They are information-theoretically secure. They operate in a distributed manner, assume no knowledge of the topology, and can be designed and implemented in polynomial time. Furthermore, only the source and destination need to be modified; nonmalicious nodes inside the network are oblivious to the presence of adversaries and implement a classical distributed network code. Finally, our algorithms work over wired and wireless networks
- …