Method for accessing a transmission channel in a wireless communication network with a contention window

摘要

The invention relates to a transmission control method of a set of transmitter/receiver systems of a local network comprising N transmitter/receiver systems wishing to transmit at least one data packet via the wireless local network, each transmitter/receiver system wishing to transmit said at least one data packet after a contention period during which a transmitter/receiver is or is not authorized to transmit the data packet of said transmitter/receiver, the method being characterized in that the contention period is broken down into R consecutive contention windows where R≧1, each contention window being broken down into K intervals of equal duration θ followed by an interval of duration δ, each contention window corresponding to a round r of contention; and in that the method comprises a step of determining the number K of intervals and the number R of contention windows, on the basis of the number N of transmitter/receiver systems wishing to transmit at least one data packet via the wireless local network.

主权项

1. A method for controlling transmission by a set of nodes in a local wireless network comprising N nodes wishing to transmit at least one data packet via the local wireless network after a contention period during which a node is authorised or is not authorised to transmit its data packet, said method comprising a step of determining parameters of the contention period, said parameters being a number of slots K and being a number of R≧1 successive contention windows each contention window being divided into K equal slots of duration θ followed by a slot of duration δ, each contention window corresponding to a round r of contention; and the parameters of the contention period being determined as a function of the number N of nodes wishing to transmit at least one data packet via the local wireless network; wherein the determination of the number of slots K and the number R of contention windows consists of iteratively testing several values of the number of the slots K together with a participation probability Pp translating a probability of whether or not obtaining authorisation to transmit its data packet during the contention period in the following manner;
(a) defining a value of a participation probability Pp; (b) defining the number K of slots in the size of the contention window; (c) determining the probability of success Pα as a function of the number N of nodes in the wireless communication network wishing to transmit a data packet, the size K of the contention window and the participation probability Pp, the probability of success Pα translating successful transmission of the data packet during a round r of contention; (d) repeating steps (a) to (c) until Pα>threshold with the threshold value being fixed in advance.