Yusuke Koda

and 3 more

This study aims to provide a unified view of the various standard millimeter-wave (mmWave) channel modeling frameworks for mmWave wireless deployments in sixth-generation (6G) wireless networks, focusing on wireless personal area networks (WPAN), wireless local area networks (WLAN), and cellular networks (CN). The 6G era will witness the emergence of security-sensitive, more mission-critical, and data-intensive applications, wherein massive amount of data will be exchanged while satisfying the stringent requirements for latency, reliability, trustworthiness, and data rate. Thus, mmWave connectivity has been considered and would result in the co-existence of decentralized networks and centralized CNs, eventually blurring the distinction between WPANs, WLANs, and CNs. Motivated by this futuristic vision, we first reviewed the present status of the standard channel models for WPAN, WLAN, and CNs to understand the common characteristics of mmWave channel models therein. We show that despite their differences in sight- specificity levels and employed mathematical functions, all standard channel models target the generation of a commonly structured channel impulse response comprising eight shared components. Furthermore, based on the affinity, we propose a research direction to develop unified mmWave channel generation for WPAN, WLAN, and CN, where channel simulations for the three scenarios can be conducted in an identical framework. Our experimental results shed light on the feasibility of the proposed research direction and highlight the challenges and opportunities.This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessible

Yusuke Koda

and 3 more

This study conducts a wideband multi-path propagation measurement at the 95 GHz sub-terahertz band for short-range communication in a conference room desktop scenario. Regardless of the fact that the current 3rd generation partnership (3GPP) stochastic channel model (SCM) targets the frequency up to 100 GHz for various scenarios, neither detailed measurements at the 95 GHz band nor a compatible channel modeling/generation framework for indoor short-range communication scenarios have been conducted. To fill these voids, based on a real-world measurement at 95 GHz with a bandwidth of 4 GHz, this study analyzes the multi-path propagation characteristics and yields the following insights for developing a 3GPP SCM-compatible channel generation framework at this band. First, the exponential power decay with delay time and quasi-uniform azimuth angles of arrival (AAoAs) are observed, which should be revisited to develop a channel generation framework. Secondly, distribution models for root mean squared (RMS) delay/AAoA spreads and omnidirectional path loss model are derived, which serves as a foundation for developing a channel generation framework at this band. Moreover, these established models are compared with the recently conducted measurement results at the 60 GHz band in the same scenario, shedding light on the hypothesis that the models for these parameters at the 60 GHz can be generalized for the 95 GHz band. “© 2024 IEEE.  Personal use of this material is permitted.  Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Published Version:10.1109/WCNC57260.2024.10571036

Yusuke Koda

and 3 more

This paper performs a first wideband indoor channel measurement at the 105 GHz sub-terahertz (sub-THz) band and analyzes the multipath characteristics in terms of the omnidirectional path-loss and angular characteristics. The measurement campaigns with the 4 GHz bandwidth are performed focusing on indoor short-range communication scenarios in a conference room, corridor, and office room, which have been considered in the primary 60 GHz communication systems standardized by the IEEE 802.15.3c/11ad. Moreover, to draw full understanding to scale the 60 GHz indoor channel models and 60 GHz system designs for the 105 GHz band, we also conduct 60 GHz channel measurements in the same environment with few modifications in the channel-sounding system and performed the comparison between these two bands. Based on these measurements, we demonstrate the affinity that exists between 105 GHz and 60 GHz bands in terms of path loss exponent and angular characteristics of multipath components, shedding light on the hypothesis that several system designs of the 60 GHz communication systems (e.g., beam switching for non-line-of sight conditions) can be applied to the 105 GHz sub-THz communication systems. © 2023 IEEE.  Personal use of this material is permitted.  Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

Rei Hirakawa

and 2 more

In recent years, extensive research has been conducted on Internet of Things (IoT). Wireless Smart Ubiquitous Network (Wi-SUN) has gained considerable attention as a wireless communication standard for IoT. Wi-SUN Field Area Network (Wi-SUN FAN) is a technical specification of Wi-SUN that can be implemented in both indoor and outdoor IoT communication infrastructure with multi-hop routing. Although Wi-SUN FAN version 1.0 (Wi-SUN FAN 1.0) has been standardized by IEEE 2857-2021, there have been no studies or reviews conducted on the transmission performance of Wi-SUN FAN 1.0 regarding transmission success rate and delay time using computer simulations and experimental evaluation environments involving actual devices. In this study, the specifications of the Wi-SUN FAN are reviewed, and the fundamental transmission performance, such as average transmission success rate and average delay time, is measured using computer simulation as reference data. An experimental evaluation environment involving actual devices is developed to validate the characteristics evaluated by computer simulation. The characteristics determined by the computer simulation and experimental evaluation environment are in good agreement. Using the validated simulator, we evaluate the transmission performance in the wireless IoT environment with one border router and 100 routers randomly arranged in a flat square field with 4,000 m on a side. The average transmission success rate is approximately 1 at 1.00 × 10–1 s–1 or less. Consequently, Wi-SUN FAN 1.0 can communicate with a higher transmission success rate even when transmitting frequent IoT-data, which is once every ten seconds. This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessible.