Patent ID: 11917569
Assignee: LANDIS+GYR TECHNOLOGY, INC.
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 14:
15. An endpoint device of a network comprising:
a crystal oscillator configured for generating an oscillating signal with a frequency of the crystal oscillator;
a processor configured to execute computer-readable instructions; and
a memory configured to store the computer-readable instructions that, when executed by the processor, cause the processor to perform operations comprising:
while operating in an initial communication mode,
receiving a reference timing signal over the network from a reference device in the network, wherein the reference device is synchronized to a clock with a frequency of higher accuracy and stability than the frequency of the crystal oscillator;
obtaining a current value of the frequency of the crystal oscillator;
determining a frequency difference between a reference frequency of the reference timing signal and the current value of the frequency of the crystal oscillator;
causing a control signal to be generated based on the frequency difference;
adjusting the frequency of the crystal oscillator by applying the control signal to the crystal oscillator; and
determining that an error of the frequency of the crystal oscillator satisfies a pre-determined condition;

causing the endpoint device to switch to a narrowband or ultra-narrowband communication mode in response to determining that an error of the frequency of the crystal oscillator satisfies a pre-determined condition, wherein a data rate of the narrowband or ultra-narrowband communication mode is lower than a data rate of the initial communication mode; and
while operating in the narrowband or ultra-narrowband communication mode, causing the endpoint device to communicate with another device in the network using an oscillating signal generated by the crystal oscillator.