Research and Development on Indoor Distributed Local 5G Systems and LPWAN Downlink Communications
This booth presents research from the Yamazaki Laboratory, Tokai University.
(1) Local 5G: Experimental evaluation of radio propagation and communication performance in indoor distributed base station environments, with exploration of applications.
(2) LPWAN: Study of LoRaWAN downlink communications through theory and experiments, clarifying performance and design insights.
| Booth No | W-8 |
|---|---|
| Address | 2-3-23 Takanawa, Minato-ku, Tokyo 108-8619 |
| Phone Number | |
| FAX | |
| Site URL | https://www.u-tokai.ac.jp/ud-information-and-telecommunication-engineering/ |
| Company Video URL |
Main Exhibitor
Products / Services
Radio Propagation and Communication Quality of Indoor Distributed Local 5G Systems in Underground Environments
A local 5G system consisting of three distributed radio base stations (Radio Units, RUs) has been introduced in the underground area of ??our Shinagawa campus. In this system, each RU, assigned a different physical cell ID (PCI), operates on the same frequency, posing a challenge for inter-cell same-channel interference in the downlink. Starting from this issue, we are evaluating the radio wave propagation environment based on field measurements using specialized measuring instruments. Specifically, we identify points with maximum or minimum received signal strength, as well as cell boundaries susceptible to interference from multiple RUs, and clarify communication quality such as throughput in these areas.
Furthermore, focusing on the fact that the relationship between the synchronous signal-reference signal received power (SS-RSRP) and the synchronous signal interference ratio (SS-SIR) can be expressed as a simple linear equation on the logarithmic plane, we are proposing a new performance analysis method for radio wave propagation.
We can provide the above information at this booth, and we would be happy to discuss it with you if you are interested.
Experimental Validation and Theoretical Analysis of LoRaWAN Class B Mode
As a use case for IoT, we envision the realization of smart cities and are conducting research on downlink communication (Class B mode) of LoRaWAN, an unlicensed LPWAN, from both theoretical and experimental perspectives.
First, as a theoretical study, we extended the energy consumption model we had previously developed for uplink communication (Class A mode) to construct a mathematical model that includes downlink communication (Class B mode). This made it possible to easily calculate energy consumption and energy efficiency associated with communication from key parameters such as beacon period, ping slot number, and spreading factor. This result has already been presented at the international conference IEEE WCNC2026.
Next, as an experimental evaluation, we designed and developed a sensor node compliant with the LoRaWAN Class B specification and successfully achieved downlink communication and control up to approximately 2.4 km in a dense urban environment (Tokyo, Shinagawa area).
We can provide the above information at this booth, so we would be happy to discuss it with you if you are interested.