摘要
低速率无线个域网LR-WPANs为保证实时和可靠通信,采用了IEEE 802.15.4信标使能的超帧结构,并且扩展了保障时隙GTS机制,解决了移动无线传感器网络中节点连通性较弱的问题,并且对确定性延迟上界的计算具有重要意义。采用仿射函数描述网络节点输入数据流累积函数的到达曲线,提供基于速率-延迟模型的服务保障。应用网路演算理论得到保障时隙的延迟确界,分析了超帧系数对延迟的影响。结果表明,在时间敏感的工业应用领域,超帧系数应该根据突发数据量同步改变。
In order to guarantee real-time and reliable communication, LR-WPANs only takes account of the beacon-enabled IEEE 802.15.4 superframe structure and extends its guaranteed time slot mechanism. Deterministic delay plays a decisive part in the using of IEEE 802.15.4 and its upper bounds need to be accurately calculated. Each data flow has a cumulative arrival function R(t) upper bounded by the arrival curve of affine functions, and the node provides rate-latency service for the flow. Then the delay bound is evaluated by using network calculus theory. Based on those results, the impact of superframe parameters on the delay bound is analyzed and it was found that that superframe order should improve on synchronous with busrt size for time sensitive industrial applications.
出处
《江南大学学报(自然科学版)》
CAS
2012年第4期478-483,共6页
Joural of Jiangnan University (Natural Science Edition)
基金
河北省科学技术研究与发展计划项目(11213566)
关键词
保障时隙
速率延迟
仿射函数
网络演算
guaranteed time slot
rate-latency
affine functions
network calculus