Demonstration of wireless two-way interferometry (Wi-Wi)

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

doi:10.1587/comex.2016xbl0181

Cited by 20 publications

(17 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In our previous paper [11], we reported a deviation of 2.2 ps in propagation time measurement when the antennas were stationary. This means that we can monitor the variation of the distance between the antennas with 1 mm precision since the wireless signal travels about 1 mm in 0.3 ps.…”

Section: B Calculating Distance Using Carrier Phasementioning

confidence: 87%

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

Panta¹,

Kido²,

Yasuda³

et al. 2019

Sensors and Materials

Self Cite

View full text Add to dashboard Cite

We demonstrated a simple technique for monitoring range variation with millimeter-precision between two remote sites using off-the-shelf wireless communication modules. The need for the flexible positioning of wireless devices is significantly increasing as more devices are being connected and new services are being developed that require devices to collaborate with one another. We showed that one can monitor the distance variation by analyzing the propagation delay of the wireless communication signal between devices. We previously reported a technique for synchronizing clocks with picosecond precision by monitoring the time variation of two rubidium clocks located at remote sites. Precise measurement of the propagation time variation was necessary for precise synchronization of the clocks, and we used this information to estimate the distance with high precision. In a localized situation, our technique makes it easy to implement a millimeter-precision measurement system. Furthermore, it is less complex in terms of system design and can be a low-cost alternative to existing systems that require precise position measurement. We envision that this demonstrated protocol will be implemented in wireless communication chips and microprocessing units.

show abstract

Section: B Calculating Distance Using Carrier Phasementioning

confidence: 87%

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

Panta¹,

Kido²,

Yasuda³

et al. 2019

Sensors and Materials

Self Cite

View full text Add to dashboard Cite

show abstract

“…where λ is the mean arrival rate, which is defined in (15), and µ is the mean of service rate, which derives from the inverse of the service time. If ρ ≥ 1, the length of the queue or the wait becomes infinity, meaning that the traffic is beyond its capacity.…”

Section: ) Details Of Simulation Methodsmentioning

confidence: 99%

“…Note that we can track the variation of t c from the beginning of the measurement if the variation of φ A and φ B between the successive measurements is smaller than π, which corresponds to the requirement of a sufficiently short roundtrip time. The successful phase unwrapping has already been demonstrated in [15].…”

Section: A Two-way Time Transfermentioning

confidence: 99%

See 1 more Smart Citation

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

et al. 2021

Self Cite

View full text Add to dashboard Cite

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).

show abstract

“…Complex arbitration methods may impose significant overhead or delay, which can hinder the inherent advantages of optical signal transmission. Meanwhile, Shiga et al developed a precision time synchronization technique called wireless two-way interferometry, also known as Wi-Wi [3][4][5] to address this issue. In this study, we have employed such a time synchronization technique to facilitate arbitration of communication in optical networks and even general information networks.…”

Section: Introductionmentioning

confidence: 99%

Low latency information transfer based on precision time synchronization via wireless interferometry

Koyama

Wang

Shiga

et al. 2021

NOLTA

Self Cite

View full text Add to dashboard Cite

The growing demand of high-bandwidth and low-latency information transfer in information and communication technologies such as data centres and in-vehicle networks has increased the importance of optical communication networks in recent years. However, complicated arbitration schemes can impose significant overheads in data transfer, which may inhibit the full exploitation of the potential of optical interconnects. Herein, we propose an arbitration protocol based on precision time synchronization via wireless two-way interferometry (Wi-Wi), and numerically validate its efficiency including the ability to impose a strict upper bound on the latency of data transfer.Compared with the conventional carrier sense multiple access/collision detection (CSMA/CD)-based approach, a significant improvement in the data transfer was observed especially in the cases with high traffic flow rate.Furthermore, we conducted a proof-of-principle experiment for Wi-Wi-based data transfer between two electrically connected nodes and confirmed that the skew was less than 300 ns and remained stable over time.Conversely, non-WiWi-based data transfer exhibited huge and unstable skew. These results indicate that precision time synchronization is a promising resource to significantly reduce the communication overheads and ensure low latency for future networks and real-time applications.

show abstract

Demonstration of wireless two-way interferometry (Wi-Wi)

Cited by 20 publications

References 2 publications

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

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

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

Low latency information transfer based on precision time synchronization via wireless interferometry

Contact Info

Product

Resources

About