Dynamic rate control in WiFi systems

摘要

A wireless device is configured to switch data rates to account for temporary channel conditions or device configuration errors. Pre-selected data rates, more likely to achieve maximum goodput, are stored in a data rate table. The data rate table contains candidate data rates for each pre-selected data rate in the data rate table. When probe transmissions using the preselected data rates fail, dynamic rate probing is utilized to determine a possible cause and extent of the problem. The dynamic rate probing scheme transmits probe transmissions using the candidate data rates and tracks success or failure of these probe transmissions. An analysis of the probe transmissions is used to indicate a possible cause and/or extent of the problematic condition and to determine whether there is a need to reconfigure the data rates in the data rate table.

主权项

1. A method for dynamic rate adaption in a wireless network, the method comprising:
storing a plurality of pre-selected data rates for use in transmitting data in the wireless network, each pre-selected data rate associated with a number of spatial streams (Nss) and a modulating and coding (MCS) type, the pre-selected data rates being a subset of all data rates supported by the wireless network; performing one or more probe transmissions to detect a maximum achievable data rate using the plurality of pre-selected data rates; determining that the maximum achievable data rate does not meet a threshold criterion based at least in part on the one or more probe transmissions; wherein the threshold criterion is based at least in part on a member of the group consisting of: a packet error rate associated with the maximum achievable data rate and an acknowledgment status of the one or more probe transmissions; performing a probe transmission using a candidate data rate, the candidate data rate associated with a Nss and MCS type, wherein the MCS type associated with the candidate data rate is different from a set of MCS types associated with members of the plurality of pre-selected data rates assigned to a same Nss as the Nss associated with the candidate data rate; and adding the candidate data rate to the plurality of pre-selected data rates based at least in part on whether the candidate data rate meets the threshold criterion during the probe transmission.