Indoor Factory RSRP and RTT Measurements at 3.7 GHz: Simulator and Analysis

Deterministic channel models for indoor areas are highly complex, especially in cluttered environments such as factory halls. This paper presents measurements taken in a factory hall of an existing communication network to allow parameterization of an accurate channel model. These measurements include the reference signal received power (RSRP) and round-trip time (RTT). Additionally, 5G-FINS, an open source channel model simulator designed for complex indoor areas, is introduced. Four different indoor 5G channel models, appropriate for factory settings, are available to be easily visualized and compared. The tool supports the addition of walls, of varying material and thickness, and clutter areas in the environment, that can be taken into account by the models. The measurement data was analyzed and the resulting channel model parameters can be changed in 5G-FINS in an easy to use graphical user interface. For scenarios where few radio dots are active and there is a lot of non-line-of-sight (NLOS) between the radio dot and the user, the parameterized alpha-beta-gamma model with NLOS considerations is recommended, and for networks with larger numbers of radio dots, the simpler freespace path loss model performs well. A clear relationship between signal strength and RTT is observed and the corresponding probabilities for various link quality thresholds are presented. The simulation and measurement data show an outstanding fit showing great potential for the use of 5G-FINS in the design of high performance, latency and quality of service (QoS) critical indoor 5G networks.