一种改进的低时延无线传感器网络MAC协议 / An improved low-delay MAC protocol for WS Ns
- Resource Type
- Academic Journal
- Authors
- 周瞡; ZHOU Jing
- Source
- 郑州轻工业学院学报(自然科学版) / Journal of Zhengzhou University of Light Industry (Natural Science Edition). (4):82-87
- Subject
- IEEE 802.15.4
Markov链模型
低时延
MAC协议
Markov chain model
low-delay
MAC protocol
- Language
- Chinese
- ISSN
- 2095-476X
针对无线传感器网络IEEE 802.15.4 MAC 协议存在传输时延高的问题,在现有低能耗机制LE-MAC(low-energy MAC)的基础上,提出一种具有低时延特征的新机制LD-MAC(low-delay MAC).该机制通过改进CCA检测的次数来达到降低时延的目的,在站点竞争窗口成功退避到0后,进行第1次CCA空闲检测,若发现信道空闲,则直接发送数据.采用二维Markov链模型对改进机制的性能进行理论分析,实验结果表明,LD-MAC只需轻微增加能耗,就能有效地降低传输时延,并且提高信道接入概率和网络吞吐量.
Aiming at the problem that IEEE 802.15.4 MAC protocols in wireless sensor networks had high delivery latency,an improved low-delay MAC mechanism LD-MAC based on the existing LE-MAC protocol was proposed.The protocol reduced the delivery latency by improving the number of CCA.When the back-off counter reached zero,the node performed carrier sensing that consisted of clear channel assessment (CCA)for the next CW consecutive backoff slots.If the channel was sensed idle during the first CCA,the node tansmitd the data directly.The properties of the improved mechanism were analyzed theoretically by using two-dimensional Markov chain model.The simulation results showed that LD-MAC not only reduced the delivery latency but also improved the throughput significantly by only increasing energy consumption slightly.