Recently proposed IEEE 802.15.4-2015 MAC introduced a new prioritized contention access (PCA) for transfer of time-critical packets with lower channel access latency compared to carrier sense multiple access-collision avoidance (CSMA/CA). In this paper, we first propose a novel Markov-chain-based analytical model for unslotted CSMA/CA and PCA for industrial applications. The unslotted model is further extended to derive the analytical model for slotted CSMA/CA and PCA. Primary emphasis is laid on understanding the performance of PCA compared to CSMA/CA for different traffic classes in industrial applications. The performance analysis shows that the slotted PCA achieves a reduction of 63.3% and 97% in delay and power consumption respectively compared to slotted CSMA/CA, whereas unslotted PCA achieves a delay reduction of 53.3% and reduction of power consumption by 96% compared to unslotted CSMA/CA without any significant loss of reliability. The proposed analytical models for both slotted and unslotted IEEE 802.15.4-2015 MAC offer satisfactory performance with less than 5% error when validated using Monte Carlo simulations. Also, the performance is verified using real-time testbed.

中文翻译：

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时间关键型工业物联网应用的 CSMA/CA 和 PCA 性能分析


最近提出的 IEEE 802.15.4-2015 MAC 引入了一种新的优先争用访问 (PCA)，用于传输时间关键型数据包，与载波侦听多路访问冲突避免 (CSMA/CA) 相比，具有更低的通道访问延迟。在本文中，我们首先提出了一种新颖的基于马尔可夫链的工业应用无时隙 CSMA/CA 和 PCA 分析模型。无时隙模型进一步扩展，得到时隙CSMA/CA和PCA的分析模型。主要重点是了解工业应用中不同流量类别的 PCA 与 CSMA/CA 的性能比较。性能分析表明，时隙PCA与时隙CSMA/CA相比，时延和功耗分别降低了63.3%和97%，而非时隙PCA与时隙CSMA/CA相比，时延降低了53.3%，功耗降低了96%。无时隙 CSMA/CA，不会造成任何严重的可靠性损失。使用蒙特卡洛模拟进行验证时，针对时隙和非时隙 IEEE 802.15.4-2015 MAC 提出的分析模型均提供令人满意的性能，误差小于 5%。此外，还使用实时测试平台验证了性能。