# Suitability of NB-IoT for Indoor Industrial Environment: A Survey and Insights
## 4 Future Research Prospects
### Self-Organizing Network (SON) and NB-IoT Management  
The use of NB-IoT in industries has made activities easy, safe, effective, and more productive. However, as the number grows, the management of these devices becomes cumbersome and complex. To achieve a continuous and smooth production level, more physical efforts are required to maintain these devices. While some attempt has been made to establish network management systems (NMS), this form of management still requires physical configuration, registration, and maintenance of devices whenever they breakdown or are introduced into the network system. The management of NB-IoT is not limited to device management where provision for automatic control, including firmware upgrade, activation and deactivation, and monitoring capabilities, is required, but also network management functionalities are required to maintain network topology efficiency, synchronization of devices, and traffic congestion control. Data management can not be left out as this involves the ability to aggregate raw data for data analytics and data recovery [111].  
Since NB-IoT is a superimposition on LTE and its applications are constantly increasing in number, all the main drivers of SON that apply to LTE are also applicable to NB-IoT. These drivers include complexity and a large number of NB-IoT structured network parameters, an increase in the number of base stations (eNB) to which NB-IoT devices are attached, and a requirement of regular human intervention for configurations and management [112]. In Figure 14, the main functionalities of SON are explained as related to NB-IoT applications. The first process involves self-configuration, a process where necessary and basic configurations for system operation are automatically performed for newly deployed modules. This process starts with a stage called self-learning where parameters, such as the NB-IoT network provider, network registration status, location information, home subscriber servers, signal connection status viz idle or connected, and update on NB-IoT PSM, are all learned. This is followed by the configurations of the operational parameters, which include: eDRx, PSM, cell selection, coverage extension, Physical Resource Block (PRB), and firmware upgrade. The second process is the self-optimization process, which involves monitoring of events and performance optimization. NB-IoT uses the Service Capabilities Exposure Function (SCEF) deployment plan to monitor events, and these events include: roaming, loss of connection, traffic types viz critical, remote, and non-critical traffics, and signal quality. The performance optimization stage optimizes data transportation in the control plane Cellular-IoT (CIoT) Evolved Packet System (EPS), rate control for quality assurance, roaming for hand-off, multi-frequency band, and deployment mode for bandwidth. The third process of SON is self-healing, where paging and power class are used for outage and power maintenance. NB-IoT employs SCEF plans for User Equipment (UE) reachability, location, and change in location of the UE, communication failure, availability after DDN failure, and change of IMSI-IMEI (SV) associations [113].