Distance Variation Monitoring with Wireless Two-way Interferometry (Wi-Wi)

Panta, Bhola; Kido, Kohta; Yasuda, Satoshi; Hanado, Yuko; Kawamura, Seiji; Hanado, Hiroshi; Takizawa, Kenji; Inoue, Masugi; Shiga, Nobuyasu

doi:10.18494/sam.2019.2212

Cited by 9 publications

(10 citation statements)

References 13 publications

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“…We consider that these errors are due to the miscalculation of M c in (6) caused by the reflection of radio waves on the floor. In the previous research, the distance between antennas was set to about 400 mm [17], which was much smaller than the distance between terminals in this experiment, and the effect of reflections might be negligible in that previous experiment.…”

Section: C2 Mobility Demonstrationmentioning

confidence: 91%

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Experimental Demonstration of Delay-Bounded Wireless Network Based on Precise Time Synchronization

Tanaka,

Yamasaki,

Yasuda

et al. 2022

Preprint

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Low latency and reliable information transfer are highly demanded in 5G and beyond 5G wireless communications. However, the conventional media access control (MAC) protocol for local wireless networks sometimes unexpectedly yields significant delays due to its stochastic arbitration mechanism, resulting in the incapability of limiting the maximum delay. In the meantime, the latest precise time synchronization technology, especially wireless two-way interferometry (Wi-Wi), paves a new way to overcome such fundamental difficulties. Indeed, Yamasaki et al. proposed a new delay-bounded wireless MAC protocol named Carrier Sense Multiple Access with Arbitration Point (CSMA/AP), exploiting precise time synchronization among all devices in the network. CSMA/AP enables collision-free and delaybounded communications with a simple autonomous arbitration mechanism, unlike conventional methods such as CSMA/CA. The former study, however, was limited only to numerical examinations. Experimental demonstration and verification in wireless environments are one of the most critical steps. This paper experimentally demonstrates the fundamental principles of CSMA/AP by constructing a star-topology wireless network using softwaredefined radio terminals combined with precise time synchronization devices. We show that CSMA/AP is successfully operated, including the dynamic change of the spatial position of the terminal or the capability to ac-

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Section: C2 Mobility Demonstrationmentioning

confidence: 91%

“…where l d is the propagation distance between the two terminals, equal to the product of the speed of light c and the propagation delay t d [17]. There remains the integer ambiguity M c ; however, this can be resolved in the same manner as the measurement of t c .…”

Section: Preliminariesmentioning

confidence: 99%

Experimental Demonstration of Delay-Bounded Wireless Network Based on Precise Time Synchronization

Tanaka,

Yamasaki,

Yasuda

et al. 2022

Preprint

Self Cite

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“…where l d is the propagation distance between the two terminals, which is equal to the product of the speed of light c and the propagation delay t d [23]. There remains the integer ambiguity M c ; however, this can be resolved in the same manner as the measurement of t c .…”

Section: Preliminaries a Time Synchronization Technology: Wi-wimentioning

confidence: 99%

Experimental Demonstration of Delay-Bounded Wireless Network Based on Precise Time Synchronization

et al. 2022

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Low latency and reliable information transfer are highly demanded in fifth generation (5G) and beyond 5G wireless communications. A novel delay-bounded wireless media access control (MAC) protocol called Carrier Sense Multiple Access with Arbitration Point (CSMA/AP) was established to strictly ensure the upper boundary of communication delay. CSMA/AP enables collision-free and delay-bounded communications with a simple arbitration mechanism exploiting the precise time synchronization achieved by Wireless Two-Way Interferometry (Wi-Wi). Experimental demonstration and proving the feasibility in wireless environments are among the most critical steps before any further discussion of CSMA/AP and extension to various applications can take in place. In this work described in this paper, we experimentally demonstrated the fundamental principles of CSMA/AP by constructing a star-topology wireless network using software-defined radio terminals combined with precise time synchronization devices. We show that CSMA/AP was successfully operated, even with dynamic changes of the spatial position of the terminal or the capability to accommodate mobility, thanks to the real-time adaption to the dynamically changing environment by Wi-Wi. We also experimentally confirmed that the proposed CSMA/AP principle cannot be executed without Wi-Wi, which validates the importance of precise time synchronization. This study paves the way toward realizing delay-bounded wireless communications for future low-latency and highly reliable critical applications.INDEX TERMS Bounded delay, CSMA, MAC protocol, precise time synchronization, wireless two-way interferometry, wireless network.

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“…Each terminal has to calculate (3), ( 4) to get the accurate time difference, meaning that 1.5 roundtrip exchanges are needed. Notably, Wi-Wi is a technique to synchronize not only time but also space; indeed, it has been successfully utilized to monitor horizontal distance variations [24], [25]. On the process of t c calculation, one can also obtain t d as shown in (4).…”

Section: B Wi-wi Principlementioning

confidence: 99%

Delay-Bounded Wireless Network Based on Precise Time Synchronization Using Wireless Two-Way Interferometry

et al. 2021

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The importance of reliable information transfer in wireless networks, especially regarding communication delay, is drastically increasing to fulfill safe and high-quality communication in the 5G and post-5G era. However, conventional media access control (MAC) protocol for wireless networks, notably Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA), sometimes yields unexpectedly significant delay due to its complex arbitration mechanism assuming asynchronous communication among terminals. As the delay cannot be strictly bounded by a deterministic value, this causes a vulnerability of systems relying on wireless networks. This paper utilizes precise time synchronization achieved by Wireless Two-way Interferometry (Wi-Wi), enabling all terminals to be time-synchronized via wireless signals.We show that by an appropriate periodic assignment of each terminal's data transmission timing, named Arbitration Point (AP), a simple arbitration algorithm obtains a strictly bounded maximum value for the delay while ensuring equalities among all participants. Furthermore, we demonstrate that the total number of terminals manageable in a star-topology wireless network significantly increases by densely packing AP timings, taking into account the spatial geometry information of terminals, which is another feature delivered by Wi-Wi measurement. In the meantime, we experimentally constructed a star-topology wired network where all terminals are time-synchronized via Wi-Wi to confirm the fundamental properties identified in the proposed arbitration protocol. This study paves a new way for future wireless networks where the delay is strictly bounded and provides the basis for ultra-reliable and high-quality information transfer functionalities by utilizing precise time synchronization and space localization (space-time synchronization).

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Distance Variation Monitoring with Wireless Two-way Interferometry (Wi-Wi)

Cited by 9 publications

References 13 publications

Experimental Demonstration of Delay-Bounded Wireless Network Based on Precise Time Synchronization

Experimental Demonstration of Delay-Bounded Wireless Network Based on Precise Time Synchronization

Experimental Demonstration of Delay-Bounded Wireless Network Based on Precise Time Synchronization

Delay-Bounded Wireless Network Based on Precise Time Synchronization Using Wireless Two-Way Interferometry

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