有环网络编码关键理论问题研究

Research on Key Problems of Cyclic Network Coding

同无环网络编码研究相比,有环网络编码的理论存在更多研究空白.在实际网络中,网络编码信息流很可能交错形成环路,造成环路中链路之间逻辑因果关系混乱,时延的引入成为必须.因此,有环网络中网络编码呈现出与无环网络中不一样的特性.由于有环网络编码是网络编码实用化研究的一个关键和难点,而且有环有时延网络更接近实际网络情况,因而有环网络的研究具有较大理论和实用意义.本文从有环网络编码的数学理论框架、有环网络编码容量、码构造算法、多源有环网络编码等几个方面综述了有环网络编码的研究现状和需要进一步研究的方向.

Compared with acyclic network coding,researches on cyclic network coding have more unsolved theoretical issues.In practical network using network coding,information flows are likely to form cycles,which leads to consideration of network delays.If network delays were not considered,the causual relations between links may become disordered.Thus,characterisitcs of network coding in cyclic networks are different from those in acyclic networks.As network coding in cyclic networks is more close to practical network scenarios and also is the critical and difficult point in implementation of network coding,researches on cyclic network coding is significant both theoratically and practically.This paper summarized the key theoretic problems including mathematic theory frame,cyclic network coding capacity,code construction algorithm,and multiple sources cyclic network coding,to demonstrate achievements and the future directions.