Patent ID: 7684343
Filing Date: 2010-03-23
Classification: H04L,H04W

Abstract:
1. A data transmission method for a wireless network that includes at least one transmitter and one receiver, comprising the steps of: by the receiver, periodically estimating a signal-to-noise ratio in a signal of the transmitter and the estimate is transmitting the estimate from the receiver to the transmitter; by the transmitter, periodically estimating an average number of idle slots between two successive transmissions in the network; estimating a number of active stations, consisting of transmitters and receivers, in the network using the estimate of the average number of idle slots between two successive transmissions in the network; estimating station collision probability and an average number of stations in collision using the estimate of number of active stations in the network, before data unit transmission; extrapolating the obtained estimates of the signal-to-noise ratio, thus obtaining the extrapolated estimate of the signal-to-noise ratio; determining the optimal fragment size, optimal transmission rate and the respective value of network throughput for the basic data transmission mechanism using the extrapolated signal-to-noise ratio estimate and estimates of station collision probability and the average number of stations in collision; determining the optimal fragment size, optimal transmission rate and their respective value of network throughput for the request-to-send/clear-to-send data transmission mechanism using the extrapolated signal-to-noise ratio estimate and estimates of station collision probability and the average number of stations in collision; selecting the basic data transmission mechanism with the respective optimal fragment size and optimal transmission rate for data unit transmission, if the value of the network throughput for the basic data transmission mechanism is greater than the value of the network throughput for the request-to-send/clear-to-send data transmission mechanism; selecting the request-to-send/clear-to-send data transmission mechanism with the respective optimal fragment size and optimal transmission rate for the data unit transmission, if the value of the network throughput for the request-to-send/clear-to-send data transmission mechanism is greater than the value of the network throughput for the basic data transmission mechanism, the selected data transmission mechanism and its respective optimal fragment size are used for transmission of all fragments of a data unit, the selected optimal transmission rate is used at the first transmission of the first fragment of the data unit, before the next transmission of a fragment of the data unit; extrapolating the estimates of the signal-to-noise ratio obtained up to the moment of the beginning of the next transmission of a fragment of the data unit, thus obtaining a new extrapolated estimate of the signal-to-noise ratio, for the next transmission of a fragment of the data unit; and selecting a new optimal transmission rate using the current estimates of average number of idle slots between two successive transmissions in the network, station collision probability and the average number of stations in collision, and the new extrapolated estimate of the signal-to-noise ratio.