According to some embodiments, the cellular communication is delayed and the duration of the reservation signal is extended until a next cellular slot boundary after energy below the energy threshold is detected on the unlicensed frequency channel.

Yet another set of embodiments may include 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 perform cellular communication on the unlicensed frequency channel after transmitting the reservation signal.

According to some embodiments, the method further comprises: performing energy sensing during at least one off-duration portion in which the reservation signal is not transmitted.

According to some embodiments, the method further comprises: detecting energy greater than an energy threshold based at least in part on performing the energy sensing; and extending transmitting the reservation signal and delaying performing the cellular communication on the unlicensed frequency channel based at least in part on detecting energy greater than the energy threshold.

According to some embodiments, the method further comprises: performing energy sensing during each off-duration portion in which the reservation signal is not transmitted.