Patent ID: 11930463
Assignee: CHINA UNIVERSITY OF MINING AND TECHNOLOGY
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 2:
3. A synchronization method based on a time service and positioning network system for an underground chain-shaped large space in a coal mine, comprising following steps:
S1, transmitting, through optical fibers, information table data and time reference information between each two adjacent ad-hoc network base stations, for each group of adjacent ad-hoc network base stations based on each ad-hoc network base station arranged in an underground roadway of a target coal mine; and constructing a time service and positioning network system with a unified time reference within the adjacent ad-hoc network base stations;
S2, transmitting, through the optical fibers, the information table data and time reference information between each two adjacent ad-hoc network base stations; determining, when an error value for the time reference information transmitted between the adjacent ad-hoc network base stations is less than a corresponding preset error threshold and a duration of a state that the error value for the time reference information transmitted between the adjacent ad-hoc network base stations is less than the corresponding preset error threshold is greater than a preset time threshold, a stable operation of the time service and positioning network system between the adjacent ad-hoc network base stations, for each group of the adjacent ad-hoc network base stations; transmitting, by the adjacent ad-hoc network base stations, data to a mining switch; sending, by the mining switch, data from the adjacent ad-hoc network base stations to a mining computer or a control center to complete an operation of a total time service and positioning network; otherwise, determining that the stable operation of the time service and positioning network system between the adjacent ad-hoc network base stations is not implemented;
S3, triggering, by a terminal to be positioned, a communication connection between the terminal to be positioned and the ad-hoc network base station corresponding to a wireless signal cover range where the terminal to be positioned is located; measuring, by the ad-hoc network base station, position information of the terminal to be positioned; and returning, by the ad-hoc network base station, the position information of the terminal to be positioned to the terminal to be positioned; meanwhile, transmitting, by the ad-hoc network base station, the obtained position information of the terminal to be positioned to other ad-hoc network base stations through the optical fibers; and transmitting, by the ad-hoc network base station, the position information of the positioning terminal to the mining switch; and sending, by the mining switch, the position information of the positioning terminal to the mining computer or the control center to complete an application of the time service and positioning network system.