US 11,659,402 B2
Enhanced reservation signal for cellular communication in unlicensed spectrum
Deepankar Bhattacharjee, Milpitas, CA (US); Prateek Sharma, San Jose, CA (US); Farouk Belghoul, Campbell, CA (US); Dawei Zhang, Saratoga, CA (US); Haitong Sun, Irvine, CA (US); Wei Zeng, San Diego, CA (US); and Sreevalsan Vallath, Dublin, CA (US)
Assigned to Apple Inc., Cupertino, CA (US)
Filed by Apple Inc., Cupertino, CA (US)
Filed on Mar. 11, 2020, as Appl. No. 16/816,049.
Claims priority of provisional application 62/819,044, filed on Mar. 15, 2019.
Prior Publication US 2020/0296593 A1, Sep. 17, 2020
Int. Cl. H04W 16/14 (2009.01); H04W 72/04 (2023.01); H04W 74/08 (2009.01); H04W 84/12 (2009.01); H04W 24/04 (2009.01); H04W 72/0446 (2023.01)
CPC H04W 16/14 (2013.01) [H04W 72/0446 (2013.01); H04W 74/0808 (2013.01); H04W 84/12 (2013.01)] 20 Claims
OG exemplary drawing
 
12. A method, comprising:
by a cellular base station:
performing a listen-before-talk (LBT) procedure on an unlicensed frequency channel;
transmitting a reservation signal on the unlicensed frequency channel after successfully performing the LBT procedure, wherein the reservation signal is transmitted discontinuously such that on-duration portions of the reservation signal alternate with off-duration portions in which the reservation signal is not transmitted, and wherein respective off-duration portions between respective transmitted portions of the reservation signal have respective durations of less than one Wi-Fi slot; and
perform cellular communication on the unlicensed frequency channel after transmitting the reservation signal.