Persistent Periodic Uplink Scheduling Algorithm for Massive NB-IoT Devices

Abstract

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.

A Four-Sided Matching Game for Energy-Efficient Scheduling in Narrowband-IoT Networks

“…The authors in [8] investigate the scheduling problem for managing the generated tasks of Industrial Internet of Things (IIoT) applications in fog environments while satisfying energy and delay constraints. As for NB-IoT network, many recent articles study various aspects of the scheduling problem as in [9] and [10]. The authors in [9] consider the power-saving mode while studying the NB-IoT scheduling problem to save more energy while achieving massive connection.…”

“…As for NB-IoT network, many recent articles study various aspects of the scheduling problem as in [9] and [10]. The authors in [9] consider the power-saving mode while studying the NB-IoT scheduling problem to save more energy while achieving massive connection. The authors in [10] investigate the NPDCCH offset mechanism in resource allocation problem in NB-IoT with the objective of minimizing the consumed radio resources.…”

“…Our goal is to maximize energy efficiency, as NB-IoT devices need long battery life. We define energy efficiency as the ratio of data rate over the consumed energy as expressed in (9). The data rate (DR) is the ratio of the data size over the transmission duration as shown in (10).…”

“…In this subsection, the joint optimization problem of resource allocation and the Candidate-UE association is formulated as a four-sided matching game. The candidates rank the UEs, subcarrier indication fields, and the scheduling delay values based on their corresponding preference list through computing the EE as in (9). The association of UE i to candidate j while allocated scheduling delay k with subcarrier indication l is referred to many-to-many matching quadruple as in:…”

Energy-Efficient Uplink Scheduling in Narrowband IoT

“…Many recent works studied different aspects of NB-IoT scheduling. The authors in [ 8 ] studied the scheduling problem in NB-IoT during the power-saving mode of the devices. Their work aimed to save more energy while enabling the communication of a high number of devices with good quality of service (QoS).…”