Design of concurrent transmission MAC protocol based on S-FAMA

Abstract

The invention relates to a design of a concurrent transmission MAC protocol based on S-FAMA, which mainly comprises the following steps: establishing a system model: randomly distributing nodes in a certain sea area, and in a network initialization stage, enabling each receiving node to know the propagation time delay of a sending node in a one-hop transmission range through information interaction; dividing the time into time slots with the same size, wherein the size of the time slots is equal to the sum of the maximum propagation time delay of the maximum network and the transmission time delay of the data packet, and one round of communication is divided into four stages in total: an RST stage, a CTS stage, a DATA stage and an ACK stage; defining a concurrent transmission node and a concurrent transmission node set according to the propagation delay from the sending node to the receiving node; by the sending node, sending an RTS packet to a target node firstly, by a receiving nodein a network, determining a node set capable of concurrent transmission according to information of the received RTS packet, adding related information into a CTS packet and then broadcasting the CTSpacket to the network, and by the sending node, determining whether data transmission can be carried out or not after receiving the CTS packet.

Description

technical field [0001] The invention belongs to the technical field of underwater wireless sensor network communication, and relates to a MAC protocol for underwater wireless network communication. Background technique [0002] Underwater wireless sensor network is a research direction emerging in recent years. Due to its practicability in marine resource exploration, coastal protection, and marine environment monitoring, underwater wireless sensor network has received more and more attention. [0003] Underwater wireless sensor networks have the characteristics of high delay, low bandwidth, high bit error rate, and serious multipath effects. These characteristics undoubtedly bring great challenges to the design of underwater sensor networks. The MAC protocol is an extremely important part of the underwater wireless sensor network design. The MAC protocol is a channel access mechanism, which has a great impact on the performance of the network throughput and end-to-end delay...

AI Technical Summary

Problems solved by technology

When the network load is heavy, there will be multiple nodes competing for the right to use the channel by sending RTS control packets at the beginning of the same time slot. Due to the transmission rules of S-FAMA, data transmission may not occur effectively. Instead, it is delayed backwards, and the more delayed it is, the more nodes have data to transmit, and the phenomenon that multiple nodes send RTS control packets at the beginning of the same time slot is more serious, resulting in a vicious circle ;

[0006] 2. The size of the time slot in S-FAMA is set to the maximum propagation delay of the node plus the transmission delay of the control message, and the RTS / CTS handshake mechanism is adopted. Due to the long delay of underwater communication, The length of the time slot is a big overhead, and the RTS / CTS handshake mechanism will also bring huge time overhead. In addition, the protocol only allows one node to transmit data in a successful handshake, and the channel utilization rate is low;

[0007] 3. There is a serious problem of exposed terminals in the network