Khan Sangrez, Alvi Ahmad Naseem, Javed Muhammad Awais, Roh Byeong-Hee, Ali Jehad
Department of Electrical and Computer Engineering, COMSATS University Islamabad (CUI), Islamabad 45550, Pakistan.
Department of Computer Engineering, Ajou University, Suwon 16499, Korea.
Sensors (Basel). 2020 Apr 1;20(7):1971. doi: 10.3390/s20071971.
Internet of Things (IoT) is a promising technology that uses wireless sensor networks to enable data collection, monitoring, and transmission from the physical devices to the Internet. Due to its potential large scale usage, efficient routing and Medium Access Control (MAC) techniques are vital to meet various application requirements. Most of the IoT applications need low data rate and low powered wireless transmissions and IEEE 802.15.4 standard is mostly used in this regard which offers superframe structure at the MAC layer. However, for IoT applications where nodes have adaptive data traffic, the standard has some limitations such as bandwidth wastage and latency. In this paper, a new superframe structure is proposed that is backward compatible with the existing parameters of the standard. The proposed superframe overcomes limitations of the standard by fine-tuning its superframe structure and squeezing the size of its contention-free slots. Thus, the proposed superframe adjusts its duty cycle according to the traffic requirements and accommodates more nodes in a superframe structure. The analytical results show that our proposed superframe structure has almost 50% less delay, accommodate more nodes and has better link utilization in a superframe as compared to the IEEE 802.15.4 standard.
物联网（IoT）是一项很有前景的技术，它使用无线传感器网络来实现从物理设备到互联网的数据收集、监测和传输。由于其可能的大规模应用，高效的路由和介质访问控制（MAC）技术对于满足各种应用需求至关重要。大多数物联网应用需要低数据速率和低功耗的无线传输，在这方面大多使用IEEE 802.15.4标准，该标准在MAC层提供超帧结构。然而，对于节点具有自适应数据流量的物联网应用，该标准存在一些局限性，如带宽浪费和延迟。本文提出了一种新的超帧结构，它与该标准的现有参数向后兼容。所提出的超帧通过微调其超帧结构并压缩其无竞争时隙的大小来克服该标准的局限性。因此，所提出的超帧根据流量需求调整其占空比，并在超帧结构中容纳更多节点。分析结果表明，与IEEE 802.15.4标准相比，我们提出的超帧结构在超帧中延迟几乎减少了50%，能容纳更多节点，并且具有更好的链路利用率。
