Channel access method and node

Abstract

The invention discloses a channel access method and a node. The method comprises the following steps of: randomly selecting a backoff period XB according to a backoff exponent (BE), wherein the XB is equal to X*a UnitBackoffPeriod, and the X is a randomly selected integer in a range of 0 to (2BE-1); when the X is more than or equal to a preset value, determining a middle backoff period which is smaller than the backoff period, performing backoff until the middle backoff period is over, and performing a clear channel assessment (CCA), transmitting data if a channel is clear, continuing the backoff until the backoff period is over if the channel is not clear, performing the CCA again, and executing channel access operation according to a CCA result when the backoff period is over; and otherwise, when the X is less than the preset value, performing the backoff until the backoff period is over, performing the CCA, and executing the channel access operation according to the CCA result. According to the method and the node, when the backoff period is long, the CCA can be performed after performing backoff until the middle backoff period is over, and the data are transmitted when the channel is clear, so that data transmission time delay can be reduced.

Description

technical field [0001] The present invention relates to the communication field, and more particularly, to a channel access method and node. Background technique [0002] With the continuous in-depth research and development of wireless sensor network technology, its obvious advantages make it widely used in various fields. Performance, energy consumption, delay, etc. There have been many researches on this aspect, but the research on the backoff algorithm mainly focuses on the improvement based on the IEEE 802.11 standard. Although IEEE 802.15.4 has a certain reference function, it still needs to conduct specific analysis and research according to the specific application scenarios of low-rate wireless personal area networks. [0003] In the GB / T 15629.15-2010 standard, a slot-based carrier sense multiple access with collision avoidance (Carrier Sense Multiple Access with Collision Avoidance, referred to as "CSMA / CA") algorithm is adopted. The specific process is as follo...

AI Technical Summary

Problems solved by technology

[0009] The CSMA / CA algorithm in the standard adopts the Binary Exponential Backoff algorithm (Binary Exponential Backoff, referred to as "BEB"). Although the backoff index BE defaults to 3-5 in the standard, and the range of variation is small, the backoff time that can be selected each time Double, the backoff time randomly selected between nodes has a large difference, and macMinBE is 3, which makes the backoff time selection too large, raising the backoff time threshold, resulting in slow data access, which is not conducive to fast data interaction

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