Slotted CSMA-CA (carrier sense multiple access with collision avoidance) backoff algorithm based optimization method

Abstract

The invention discloses a slotted CSMA-CA (carrier sense multiple access with collision avoidance) backoff algorithm based optimization method. Priority settings are introduced to enable important command frames and short data frames of a sending node to be sent as soon as possible and data frames to be all sent at one time as soon as possible, and nodes used for channel competition and time delay caused by competition are decreased; the receiving and incorporating process of the frames is confirmed, success or not in sending is judged, and the communication process is more complete; a dynamic adjustment macMinBE method is adopted, the BE initial value is set, and adaptive adjustment is performed according to network load, idle and busy conditions of channels of previous task transmission and success or not in task sending; when the channels are busy, the value of macMinBE is increased, and probability of data collision can be reduced; when the channels are idle, the value of macMinBE is decreased, backoff time is shortened, time delay is reduced to a certain extent, power consumption is lowered, and network throughput is increased.

Description

technical field [0001] The present invention relates to the technical field of wireless communication transmission, and more specifically, relates to an optimization method of a time slot CSMA-CA backoff algorithm based on the IEEE802.15.4a standard. Background technique [0002] The CSMA-CA (Carrier Sense Multiple Access with Collision Avoidance) backoff algorithm refers to a channel access method that judges whether the channel is free or busy when multiple wireless nodes try to communicate with the coordinator at the same time, and avoids data collision between nodes . Under different application conditions and standards, the process will also be different. [0003] IEEE802.15.4a standard CSMA-CA algorithm workflow is divided into two ways: slotted (Slotted) and non-slotted (Unslotted). In actual use, generally only one of the methods can be determined to be used according to the usage situation. Here we focus on describing the CSMA-CA algorithm in the slot mode, and i...

AI Technical Summary

Problems solved by technology

[0004] Although the time slot method can make reasonable use of the channel to a certain extent, it cannot be implemented in time for bursty and random transmission requirements

When the load is light, the value of macMinBE will affect the average delay of nodes sending data; when the load is heavy, when multiple nodes need to send more data packets at the same time, the initial setting of macMinBE is small and easily leads to conflicts The probability of occurrence and retransmission rises sharply, and the effective transmission efficiency of the channel decreases. If the data packet cannot be sent out in time, the number of nodes that need to retransmit the data will increase, the competition will become more intense, and the vicious cycle will further reduce the transmission efficiency. In severe cases, it will lead to The system is unresponsive or even paralyzed, which greatly restricts the real-time performance and throughput of the network

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