WSN中单数据流端到端延迟上界研究

在WSN中采用独立分析（SFA）法求得的单数据流端到端延迟上界有时比整体分析（TFA）法求得的总数据流端到端延迟上界要大, 这不符合物理意义。针对这一问题, 分析了现有TFA法与SFA法在数据流服务分配机制上的差别, 并指出这两种方法求得的延迟上界不具有可比性。随后在修正流经节点数据流输出上界的基础上, 推导出与TFA法数据流服务分配机制相匹配的单数据流端到端延迟上界表达式。公式推导与数值分析结果均表明, 本方法求得的单数据流端到端延迟上界能够被TFA法总数据流端到端延迟上界所包络, 符合物理意义且更精确。

Research on single flow end-to-end delay upper bound in WSN

Present research shows that the single flow end-to-end delay upper bound got by separate flow analysis(SFA) me-thod is sometimes greater than the bound of total flow by total flow analysis(TFA) method in WSN, which is out of physical meanings. Aiming at the above problem, this paper firstly analyzed the difference in data flow's service allocation mechanism between current TFA and SFA, with pointing out that the delay bounds got by these two methods were incomparable. Finally, on the basis of the improved output bound of a data flow traversing a node, it deduced the expression of single flow end-to-end delay upper bound, which accorded with the data flow's service allocation mechanism of TFA. Both of the derived expression and numerical results illustrate that the single flow end-to-end delay upper bound got in this paper, which can be bounded by the bound of total flow by TFA, is physically significant and more accurate.