Wu Tin-Yu, Hwang Ren-Hung, Vyas Abhishek, Lin Chia-Yiu, Huang Chi-Ruei
Management Information Systems Department, National Pingtung University of Science and Technology, Pingtung 912301, Taiwan.
Computer Science and Information Engineering Department, National Chung Cheng University, Chiayi 621301, Taiwan.
Sensors (Basel). 2022 Apr 8;22(8):2875. doi: 10.3390/s22082875.
Narrowband Internet of Things (NB-IoT) is one of the low-power wide-area network (LPWAN) technologies that aim to support enormous connections, featuring wide-area coverage, low power consumption, and low costs. NB-IoT could serve a massive number of IoT devices, but with very limited radio resources. Therefore, how to enable a massive number of IoT devices to transmit messages periodically, and with low latency, according to transmission requirements, has become the most crucial issue of NB-IoT. Moreover, IoT devices are designed to minimize power consumption so that the device battery can last for a long time. Similarly, the NB-IoT system must configure different power-saving mechanisms for different types of devices to prolong their battery lives. In this study, we propose a persistent periodic uplink scheduling algorithm (PPUSA) to assist a plethora of Internet of Things (IoT) devices in reporting their sensing data based on their sensing characteristics. PPUSA explicitly considers the power-saving mode and connection suspend/resume procedures to reduce the IoT device's power consumption and processing overhead. PPUSA allocates uplink resource units to IoT devices systematically so that it can support the periodic-uplink transmission of a plethora of IoT devices while maintaining low transmission latency for bursty data. The simulation results show that PPUSA can support up to 600,000 IoT devices when the NB-IoT uplink utilization is 80%. In addition, it takes only one millisecond for the transmission of the bursty messages.
窄带物联网（NB-IoT）是低功耗广域网（LPWAN）技术之一，旨在支持海量连接，具有广域覆盖、低功耗和低成本的特点。NB-IoT能够服务大量物联网设备，但无线电资源非常有限。因此，如何使大量物联网设备根据传输要求定期且低延迟地传输消息，已成为NB-IoT最关键的问题。此外，物联网设备旨在将功耗降至最低，以便设备电池能够长时间续航。同样，NB-IoT系统必须为不同类型的设备配置不同的节能机制，以延长其电池寿命。在本研究中，我们提出了一种持续周期性上行链路调度算法（PPUSA），以协助大量物联网（IoT）设备根据其传感特性报告其传感数据。PPUSA明确考虑了节能模式和连接暂停/恢复过程，以降低物联网设备的功耗和处理开销。PPUSA系统地为物联网设备分配上行链路资源单元，以便它能够支持大量物联网设备的周期性上行链路传输，同时保持突发数据的低传输延迟。仿真结果表明，当NB-IoT上行链路利用率为80%时，PPUSA能够支持多达600,000个物联网设备。此外，突发消息的传输仅需一毫秒。
