scholarly journals Discrete Random Contention System with Variable Packet Length Based on Binary Tree Conflict Resolution Algorithm

Author(s):  
Jing Nan ◽  
Hongwei Ding ◽  
Yingying Guo ◽  
Qianlin Liu
2014 ◽  
Vol 610 ◽  
pp. 897-904
Author(s):  
Ying Ying Guo ◽  
Hong Wei Ding ◽  
Yi Fan Zhao ◽  
Jia Guo ◽  
Qian Lin Liu

This paper presents a new wireless sensor network MAC protocol: the probability detection CSMA protocol with monitoring function based on the improved binary tree conflict resolution algorithm. By using the average cycle method, the paper gets the mathematical expressions of the throughput, system average delay of the probability detection CSMA protocol with monitoring function and the probability detection CSMA protocol with monitoring function based on the improved binary tree conflict resolution algorithm through complicated mathematical modeling, rigorous mathematical derivation. The computer simulation results not only confirm the correctness of the theoretical analysis but also show that the probability detection CSMA protocol with monitoring function based on the improved binary tree conflict resolution algorithm due to adding to the conflict resolution algorithm, resulting in the increases of systemic throughput but increase the time delay of the system.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yaozheng Fang ◽  
Zhaolong Jian ◽  
Zongming Jin ◽  
Xueshuo Xie ◽  
Ye Lu ◽  
...  

Although the blockchain-based Internet of Things (BC-IoT) has been applied in many fields, it still faces many security attacks due to lacking policy-based security management (PbSM). Previous PbSM is usually time-consuming, which is difficult to integrate into BC-IoT directly. The high-latency policy conflict resolving in traditional PbSM cannot meet the BC-IoT’s low-latency requirement. Moreover, the conflict resolution rate is low as the PbSM usually neglects the runtime information. Therefore, it is challenging that achieving an efficient PbSM for BC-IoT and overcomes both time and resource consumption. To address the problem, we propose a novel PbSM for BC-IoT named FPICR to realize fast policy interpretation and dynamic conflict resolution efficiently. We first present policy templates based on system log to interpret policy in high speed in BC-IoT. Benefiting from matching the characteristics of the system processing, FPICR supports interpreting a policy into the smart contract directly without complex content parsing. We then propose a weighted directed policy graph (WDPG) to evaluate the importance of the deployed policies more accurately. To improve the policy conflict resolution rate, we implement the resolution algorithm through reconstructing the WDPG. Taking the traits of these properties, FPICR thus can also remove the redundant data to compress storage space by the WDPG. Experiment results highlight that FPICR outperforms the baseline in all measure metrics. Especially, compared with the state-of-the-art method, the speedup of interpretation in FPICR is about up to 2.1 × . The conflict resolution rate in FPICR can be improved by 6.2% on average and achieve up to 96.1%.


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