Theoretical and Practical Bounds on the Initial Value of Clock Skew Compensation Algorithm Immune to Floating-Point Precision Loss for Resource-Constrained Wireless Sensor Nodes

ABSTRACT

We revisit our prior work on clock skew compensation immune to floating-point precision loss and provide practical as well as theoretical bounds on the initial value of the skew-compensated clock based on a systematic analysis of the errors of floating-point operations; by practical bounds, we mean the actual values of the theoretical bounds calculated at resource-constrained computing platforms like WSN nodes equipped with 32-bit single-precision floating-point format. Numerical examples demonstrate that the proposed practical bounds on single-precision floating-point format do not violate the theoretical bounds and thereby can guarantee the correctness of the clock skew compensation on resource-constrained computing platforms.

KEYWORDS:

• Clock skew compensation
• floating-point arithmetic
• error bounds
• wireless sensor networks
• IEEE 754-2008

Acknowledgments

This work was supported in part by the Postgraduate Research Scholarships (under Grant PGRS1912001), the Key Programme Special Fund (under Grant KSF-E-25), and the Research Enhancement Fund (under Grant REF-19-01-03) of Xi’an Jiaotong-Liverpool University.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

¹ For instance, in the time synchronization schemes based on the reverse two-way message exchange, the clock offset is independently compensated for at the head node, while the sensor node only synchronizes the frequency of its logical clock to that of the reference clock [1].

² For detailed discussions based on a logical clock model, readers are referred to [5].

Additional information

Funding

This work was supported by the Xi’an Jiaotong-Liverpool University Key Programme Special Fund [Grant KSF-E-25]; Xi’an Jiaotong-Liverpool University Postgraduate Research Scholarships [PGRS1912001]; Xi’an Jiaotong-Liverpool University Research Enhancement Fund [REF-19-01-03].

Notes on contributors

Seungyeop Kang

seungyeop kang received the B. Eng. Degree in Mechatronics and Robotic Systems from Xi’an Jiaotong-Liverpool University in 2022, the M. Res. Degree in medical robotics and image-guided intervention from Imperial College London with the Faculty of Medicine Dean’s Prize in 2023. He later worked as a research assistant at Imperial College London to develop a miniaturized micro-probe for treatment monitoring in pancreatic cancer, collaborating with the Institute of Cancer Research, London. He is currently pursuing the Ph.D. degree with the Department of Mechanical Engineering and the Hamlyn Centre for Robotic Surgery, Imperial College London. His research interests include plasmonic optical tweezers for micro/nanoscale optical trapping and optothermal actuation of biohybrid microrobots for biomedical applications.

Kyeong Soo Kim

kyeong soo kim received B.S., M.S., and Ph.D. degrees in Electronics Engineering from Seoul National University in 1989, 1991, and 1995, respectively. From 1996 to 1997, he was engaged in the development of multi-channel asynchronous transfer mode (ATM) switching systems as a Post-Doc researcher at Washington University in St. Louis, where he also taught undergraduate and graduate courses as an Instructor of Washington University in St. Louis and Adjunct professor of University Missouri-St. Louis. From 1997 to 2000, he worked with the passive optical network (PON) Systems R&D organization of Lucent Technologies and took part in the development of the world’s first commercial ATM-PON system, which won the 1999 Bell Labs President’s Silver Award. From 2001 to 2007, he was with STMicroelectronics, working as a Principal Engineer and represented STMicroelectronics in various standard bodies, including FSAN, ITU-T, and IEEE 802.11/16 working groups; from 2001 to 2006, he also took the position of STMicroelectronics Researcher-in-Residence at the Stanford Networking Research Center (SNRC) of Stanford University. From 2007 to 2014, he worked at Swansea University as Associate Professor, where he led the Hybrid Networking Research Laboratory (HNRL) and carried out research on next-generation optical access (NGOA) and hybrid optical-wireless networks. Since 2014, he has been working at Xi’an Jiaotong-Liverpool University (XJTLU), where he is now a Senior Associate Professor. Dr. Kim is a senior member of IEEE and a member of IET.