RFClock

Time Estimation of a Miniature Atomic Clock Using Instantaneous Frequency Information

“…Although the most commonly used conventional method for time synchronization is Network Time Protocol (NTP), in wireless sensor networks, there are cases where NTP cannot be applied due to limitations such as non-IP, communication bandwidth, network topology, and asymmetric communication. Therefore, there is a need for a highly accurate timekeeping method that can be applied in such environments, and various methods have been proposed [2,3].…”

Multiple UAVs for synchronous-shared tasks and longterm autonomy

“…Jitter and wander constitute high and lowfrequency components of a clock error, respectively. The work in [79] adds additional factors related to synchronization over a network, and [82] considers errors in synchronization due to noise arising from PLL architecture. Using eq.…”

“…The general concept in wireless synchronization [83] is to transmit a low-frequency synchronization signal over a wireless channel from a centralized source with a precise clock and recover the synchronization pulse for disciplining local oscillators at multiple receiver nodes. The [82,84,85] outlines popular wireless synchronization methods and associated challenges. Some of them in [86,87,88,89] require proprietary, closed source hardware at the transmitter and receiver nodes.…”

“…Some of them in [86,87,88,89] require proprietary, closed source hardware at the transmitter and receiver nodes. At the same time, software protocols in most methods [90,91] are closed-sourced, with exceptions being [82]. Most of these methods use dedicated infrastructure to relay the synchronization signal instead of using existing physical layers or links on robots.…”

“…Most of these methods use dedicated infrastructure to relay the synchronization signal instead of using existing physical layers or links on robots. Additionally, some of them [82] use separate radios for transmitting synchronization pulse for disciplining local XO and for transmitting globally consistent 1P P S signal for time synchronization. As mentioned in [82], only a few methods can generate a reference signal that synchronizes phase, frequency, and time(-of-day) across multiple nodes.…”