A Carrier Sense Method Based on Dynamic Idle Channel Evaluation Threshold

Abstract

The invention provides a carrier sensing method based on a dynamic idle channel assessment threshold. According to the method, the existing carrier sensing mechanism is improved, and a CCA (Clear Channel Assessment) threshold is adjusted and an effective range of an NAV (Network Allocation Vector) is controlled according to the channel condition, so that the concurrent transmission in a network is increased and the network throughput is improved. According to the method, the CCA threshold is dynamically computed and adjusted according to the receiving power, so that the spatial reuse of the network can be effectively improved, meanwhile, through carrying an interference margin and a probability of acceptance at a CTS (Clear To Send) group, the range of action of the NAV in the CTS group is effectively controlled, and the spatial reuse is further improved, so that the network throughput is improved.

Description

technical field [0001] The invention relates to the technical field of communication, in particular to a carrier sensing method. Background technique [0002] A wireless local area network (WLAN) is usually accessed in a Distributed Coordination Function (DCF, Distributed Coordination Function) manner based on Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA, Carrier Sense Multiple Access with Collision Avoidance). DCF uses two carrier sense mechanisms, physical carrier sense and virtual carrier sense, to detect whether the channel is busy or idle. Only when the channel detection results of the two mechanisms are both idle, the node considers the channel idle, otherwise it considers the channel busy. Among them, the physical carrier sense adopts a fixed free channel assessment CCA threshold, and the node senses the channel. If the energy detected by the node exceeds the free channel assessment Clear Channel Assessment (CCA) threshold, the channel is considered bus...

AI Technical Summary

Problems solved by technology

[0003] With the popularization of smart devices and the enrichment of wireless applications, the phenomenon of overlapping cells has become more and more common, but the existing carrier sense mechanism (including physical carrier sense and virtual carrier sense) has greatly limited the WLAN performance

On the one hand, the fixed CCA threshold largely determines the number of concurrent transmissions, which cannot be flexibly adjusted according to network conditions

On the other hand, since the control frame carrying NAV information usually covers a large area, once the node extracts the NAV information and unconditionally accepts the NAV information, the channel reservation will be too conservative

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