MAC scheduling method of mesh underwater acoustic network

Abstract

The invention discloses an MAC (Media Access Control) scheduling method for a mesh underwater acoustic network, which comprises the following steps of: traversing all network nodes, calculating the minimum sending time difference of conflict-free transmission between each node and other nodes, sequentially arranging from small to large, and determining a scheduling sequence of each node; calculating the feasible sending time interval of each node, ensuring that the data packets sent by each sending end do not collide at the receiving end, and taking the minimum value of the feasible sending time interval as the sending time; and calculating the inter-frame conflict-free scheduling duration of each node, taking the maximum value of the scheduling duration of each node as the final scheduling duration, and enabling each node to perform sending by taking the final scheduling duration as a period. According to the invention, higher MAC scheduling capacity can be realized, and the maximum MAC scheduling capacity is approached to a greater extent.

Description

technical field [0001] The invention relates to the field of medium access control (MAC) of an underwater acoustic network, in particular to a MAC scheduling method of a mesh underwater acoustic network. Background technique [0002] The ocean area of ​​the earth accounts for 71% of the total area of ​​the earth. The study of the underwater acoustic network for ocean research and seabed detection has attracted the attention of countries all over the world. Hydroacoustic networks are currently applicable to many research fields, such as: offshore oil exploitation, pollution monitoring, tsunami warning, auxiliary navigation, ecological monitoring, etc. Media Access Control (MAC) is one of the key factors affecting the performance of underwater acoustic networks. Its main purpose is to coordinate the fair and efficient sharing of media resources among multiple nodes and avoid transmission collisions. [0003] Media access control for hydroacoustic networks differs from that fo...

AI Technical Summary

Problems solved by technology

The underwater acoustic network uses sound waves as the carrier, and the propagation speed of sound waves (1500m / s) is faster than the propagation speed of ground electromagnetic waves (3×10 8 m / s) is 5 orders of magnitude slower. Such channel characteristics make the underwater acoustic network and the wireless network have the following differences: the propagation delay of the wireless network can be ignored, and the only reason for the collision is to transmit data at the same time. Conflicts can be avoided; however, the propagation speed of underwater acoustic networks is slow, and the propagation time is extended and cannot be ignored. Data sent early but extended in propagation and data sent late but with short propagation delay arrive at the receiving end at the same time, and transmission collisions occur. So that the simultaneous transmission may not collide, but the non-simultaneous transmission may cause collision at the receiving end, that is, whether the receiving end collides depends on the mutual coupling of the transmission time and propagation delay, that is, the space-time coupling problem

Images