Method and system for measuring available bandwidth of wireless LAN

Abstract

The invention relates to an available bandwidth detecting method and system of wireless local area network. The method includes: step 1, a detecting module monitoring the frame of the channel the access point locates, reading time length fields in the frame, recording the frame conveying time length and estimating the time length of competitive channel; step 2, calculating the occupation band-width in the test cycle according to the frame conveying time length and the time length of competitive channel; step 3, judging the number of the monitored test cycles is no less than the size of the time smoothing window, if so, executing step 4, if not, executing step 1; step 4, obtaining the available band-width according to the mean value of the occupation band-width and the high limit of the band-width in the test cycle whose number is the size of the lately time smoothing windows. Thereby the available band-width can be monitored without changing the prior wireless local area network equipment.

Description

technical field [0001] The invention relates to the field of wireless local area networks, in particular to a method and system for measuring available bandwidth of a wireless local area network. Background technique [0002] The wireless LAN of IEEE 802.11 protocol uses the shared channel mode, and all mobile terminals associated with the same access point (AP) share the total bandwidth of the wireless LAN. [0003] In IEEE 802.11, a DCF (Distributed Coordination Function, distributed coordination function) communication mode is a medium access control method adopted in a wireless local area network, which includes a virtual carrier sense mechanism. The virtual carrier sense mechanism uses NAV (Network Allocation Vector) to realize virtual carrier sense to avoid conflicts on wireless links. Among them, NAV indicates the possible occupancy time of the current channel, and the mobile terminal updates the NAV value recorded by itself according to the duration field (Duration / ...

AI Technical Summary

Problems solved by technology

However, this method simply takes the sum of the duration fields in the frame sent by the network node as the time for NAV to occupy the channel. This calculation method has a large number of repeated superpositions, which will overestimate the occupancy rate of the wireless channel

In addition, Backoff is not given in the text Si The specific meaning and calculation method of , and only the back-off of the node is considered, which does not meet the characteristics of 802.11 shared channels

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