A PRECISE TIME-BOUND TIME DIVISION MULTIPLE ACCESS METHOD OF UNDERWATER ACOUSTIC NETWORKS

摘要

The present invention relates to a precise time-boundary time division multiple access method of a underwater acoustic network for maritime communications, comprising: (a) a step wherein a predetermined master node, among a plurality of master nodes, acquires the current propagation delay based on a data packet received from a predetermined underwater node, among a plurality of underwater nodes, in the current transmission cycle in order to calculate an estimated propagation delay; (b) a step wherein the predetermined master node calculates the estimated propagation delay in the following transmission cycle of the predetermined underwater node and a preliminary starting point of a data time slot in order to calculate the downlink expansion-estimated propagation delay in the following transmission cycle; (c) a step wherein the predetermined master node calculates the downlink expected delay change amount and the uplink expansion-estimated propagation delay in the following transmission cycle, using the waiting time of the predetermined underwater node assigned to the data time slot and the elapsed time of the arrival of a beacon packet and the data packet; (d) a step wherein the predetermined master node calculates the starting time, length, and ending time of the data time slot in order to determine the data transmission schedule; and (e) a step wherein the predetermined master node adjusts the length of the time slot which is allocated to each of the underwater nodes, determines the starting point of the data transmission of the predetermined underwater node in the following transmission cycle, and broadcasts the beacon packet in the following transmission cycle to the underwater nodes.