Abstract:
The present invention relates to an enhanced ad-hoc self-organizing time division multiple access (EASO-TDMA) type media access control method for a 2nd generation modem, comprising a first phase (FP) processing step including network entry, time slot scanning, neighboring ship (NS) checking, and path setting, and a normal phase (NP) processing step of transmitting a packet during an occupied time slot using a given path and receiving packets of neighboring ships during the other times. According to the present invention, since the number of time slots of a ship is set according to the number of transmission nodes by using a route table, and a time slot is allocated to communicate to a destination during one frame, a transmission delay time can be reduced and occurrence of an application timeout can be prevented, and thus, wireless communication with a land based station, as well as communication between marine neighboring ships, can be more stably performed.
Abstract:
The present invention relates to a time parameter determining method of a time division multiple-access media access control protocol for a long range underwater network in which a command ship prevents the generation of reception collision between the command ship and cluster heads and performs effective two-way communication. For this, the command ship (CS) sets the time parameter according to the position of a different cluster head (CH) into an initial stage, a normal stage, and a final stage and controls the connection of the entire channel. The CH determines the time parameter of media access control protocol connected to the channel based on the time parameter provided from the CS. The time parameter determining method of the time division multiple-access media protocol comprises: a step of determining a beacon signal time offset of a CH j in a hop h and sub-hop k; and a step of determining a response signal transmission time offset of the CH j in the hop h and sub-hop k. [Reference numerals] (AA) Initial stage; (BB) Bus bar mac (MAC); (CC) Cluster head mac (MAC); (S210) Time parameter setting; (S220) Beacon signal transmission; (S230) Beacon signal transfer; (S240) Response signal transmission; (S250) Response signal transfer; (S260) Route setting; (S270) Route setting confirmation