RATELESS PACKET SCHEME FOR DISTRIBUTED RATELESS CODING IN NETWORKED SYSTEMS

摘要

In the proposed invention we present a novel approach for data gathering applicable on different networked systems (such as wireless sensor networks, wireless ad-hoc networks, peer-to-peer/overlay networks) based on a new packet-centric principle applied for distributed rateless coding. Standard (centralized) rateless codes are an efficient, low- complexity solution for coded data transmission over channels with packet erasures, which motivates their application in distributed network scenarios. Several recently proposed distributed rateless coding techniques in network environments are based on node-centric principles, i.e., collecting sufficient number of different network node information data packets and performing rateless encoding is the task of network nodes. In the presented packet-centric approach, this task is assigned to encoded packets called rateless packets. While randomly moving through the network, rateless packets collect and encode into their content required number of uniformly sampled information data packets, finishing their paths in randomly selected network nodes. This simple shift in encoding paradigm results in many advantages of the rateless packet scheme: (i) it is very simple to design and implement as compared to rather complicated algorithms presented in previous publications on this topic, (ii) any rateless code degree distribution can be obtained exactly, a feature not satisfied by previous proposals where it is approached asymptotically, (iii) the performance closely approaches the performance of the centralized rateless codes, and (iv) the scheme is open for parameter optimization for different applications and easily allows for trading off the energy efficiency, bandwidth consumption and performance.