一种考虑节点拥塞情况的DTN概率路由算法*

容迟网络是一种新型网络,其概率路由算法根据历史相遇频率对相遇概率进行计算与更新,通过相遇概率判断是否转发报文。当节点缓存受限时,在网络中采用概率路由算法使得节点很容易发生拥塞,对报文的传送产生影响。为了减小拥塞对概率路由算法的影响,提出了一种考虑节点拥塞情况的概率路由算法,将节点相遇的概率和节点拥塞的情况综合起来,得到一个报文的递交概率,降低了由于拥塞对网络性能的影响,提高了报文的递交率,减小了报文在缓存中排队等候的时间。仿真结果表明,与传统的概率路由算法相比,在改进后的概率路由算法中报文递交率显著提高,平均延迟也在降低。

Probabilistic routing algorithm based on node congestion in DTN

The delay tolerant network is a new network system structure. The probabilistic routing algorithm calculates and updates encounter probability based on encounter frequency of history, and determines whether to forward messages according to the encounter probability. When the buffer of the node is restricted by the size, the networks that use the probabilistic routing would more easily have node congestion, influence the transmission of the messages. In order to reduce the influence of the congestion on the PROPHET, this paper proposed PROPHET-NC (probabilistic routing algorithm based on node congestion), which combined encounter probability with the node congestion situation to estimate delivery probability of messages, lessened the influence on network performance caused by the congestion, enhanced the delivery probability, reduced the time that messages stay in the buffer. The simulation results show that comparing to the PROPHET, in PROPHET-NC the delivery probability of message is obviously increased higher and the average latency is decreased.