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Faculty Sponsor

Dr. Todor Cooklev

Department/Program

Department of Electrical & Computer Engineering

University Affiliation

Indiana University – Purdue University Fort Wayne

Abstract

When the clocks in our lives get out of sync, bad things happen. We arrive late for meetings, miss the train, or record all but the last few minutes of our favorite television show. Wouldn't it be helpful if clocks were always set to the correct time? Actually, if they were networked together and using the IEEE 1588 Precision Time Protocol, they could all be set to same time, typically within 100 nanoseconds of each other. The IEEE 1588 protocol enables rapid convergence (typically less than a minute, depending on the network topology) to sub-microsecond time synchronization between heterogeneous distributed devices controlled by clocks of differing resolution and stability.

IEEE 1588 can be implemented solely in software to give accuracy in the sub-100 microsecond range. This is similar to that seen with other software implemented protocols such as NTP that operate across the same network topology. However, if time stamping is performed in the application layer, interrupts and other unpredictable software processes can introduce jitter and latency which may impair the synchronization. Even the use of a very precise external oscillator won't overcome the stack jitter associated with a software-only 1588 implementation.

Most applications require the higher accuracy achieved by time stamping packets at the interface between the physical (PHY) and data link (MAC) layers ("hardware time stamping"). IEEE 1588 hardware time stamping typically improves accuracy to 100 nanoseconds or better for certain network configurations, which is better than NTP.

My undergrad research focuses on the hardware implementation of time stamping techniques and the efficiency improvement methods of IEEE 1588.

Disciplines

Electrical and Computer Engineering | Engineering

IEEE 1588 and accurate Time Stamping Techniques

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