US Patent No. 10,117,271

CONTENTION WINDOW ADJUSTMENT IN UNLICENSED CELLULAR RADIO NETWORK


Patent No. 10,117,271
Issue Date October 30, 2018
Title Contention Window Adjustment In Unlicensed Cellular Radio Network
Inventorship Rickard Ljung, Helsingborg (SE)
Assignee SONY MOBILE COMMUNICATIONS INC., Tokyo (JP)

Claim of US Patent No. 10,117,271

1. A method carried out in a base station of a cellular radio communications network configured to transmit data to a terminal in an unlicensed radio band, comprising the steps of:determining a contention window, within which to transmit data between the base station and a terminal;
receiving a signal from the terminal, comprising an indication of occupancy of a radio channel, as detected by the terminal;
establishing a metric on a number of Not Acknowledged (NACK) feedback values received on the radio channel in respect to a predetermined period of time;
comparing the indication of occupancy to a first threshold value;
in response to determining that the indication of occupancy meets or exceeds the first threshold value, comparing the metric with a second threshold value;
in response to determining that the metric meets or exceeds the second threshold value, increasing the contention window size; and
transmitting data to the terminal within the increased contention window.