A method of operation of a node of a cellular communications network, comprising: performing a Listen-Before-Talk, LBT, procedure for an observed channel in an unlicensed frequency spectrum, the LBT procedure deferring at least one Clear Channel Assessment, CCA, slot such that the LBT procedure concludes at a desired starting point for a transmission, the at least one CCA slot comprising at least one of a first CCA slot of the LBT procedure, one or more intermediate CCA slots of the LBT procedure, and a final CCA slot of the LBT procedure, wherein the desired starting point for the transmission is subframe boundary, slot boundary, or a predefined offset from the start of a subframe, where the transmission is a data transmission, and performing the LBT procedure comprises: randomly selecting a backoff counter, N; observing the observed channel during the first CCA slot having an initial CCA duration, T0; upon determining that the observed channel is busy during the first CCA slot, deferring a next CCA slot to a next desired CCA slot starting point that is predetermined relative to a subframe boundary or is a subframe boundary; observing the observed channel during the next CCA slot having the initial CCA duration, T0, starting at the next desired CCA slot starting point; upon determining that the observed channel is idle during the first CCA slot: observing the observed channel during an additional CCA slot having a CCA duration, T1; and upon determining that the observed channel is busy during the additional CCA slot, deferring a next CCA slot to a next desired CCA slot starting point that is predetermined relative to a subframe boundary or is a subframe boundary, wherein if the observed channel is idle during the additional CCA slot, then decrementing the backoff counter N by one and determining if N is equal to zero; and performing the transmission on the observed channel upon determining that N is equal to zero. performing a Listen-Before-Talk, LBT, procedure for an observed channel in an unlicensed frequency spectrum, the LBT procedure deferring at least one Clear Channel Assessment, CCA, slot such that the LBT procedure concludes at a desired starting point for a transmission, the at least one CCA slot comprising at least one of a first CCA slot of the LBT procedure, one or more intermediate CCA slots of the LBT procedure, and a final CCA slot of the LBT procedure, wherein the desired starting point for the transmission is subframe boundary, slot boundary, or a predefined offset from the start of a subframe, where the transmission is a data transmission, and performing the LBT procedure comprises: randomly selecting a backoff counter, N; observing the observed channel during the first CCA slot having an initial CCA duration, T0; upon determining that the observed channel is busy during the first CCA slot, deferring a next CCA slot to a next desired CCA slot starting point that is predetermined relative to a subframe boundary or is a subframe boundary; observing the observed channel during the next CCA slot having the initial CCA duration, T0, starting at the next desired CCA slot starting point; upon determining that the observed channel is idle during the first CCA slot: observing the observed channel during an additional CCA slot having a CCA duration, T1; and upon determining that the observed channel is busy during the additional CCA slot, deferring a next CCA slot to a next desired CCA slot starting point that is predetermined relative to a subframe boundary or is a subframe boundary, wherein if the observed channel is idle during the additional CCA slot, then decrementing the backoff counter N by one and determining if N is equal to zero; and performing the transmission on the observed channel upon determining that N is equal to zero. randomly selecting a backoff counter, N; observing the observed channel during the first CCA slot having an initial CCA duration, T0; upon determining that the observed channel is busy during the first CCA slot, deferring a next CCA slot to a next desired CCA slot starting point that is predetermined relative to a subframe boundary or is a subframe boundary; observing the observed channel during the next CCA slot having the initial CCA duration, T0, starting at the next desired CCA slot starting point; upon determining that the observed channel is idle during the first CCA slot: observing the observed channel during an additional CCA slot having a CCA duration, T1; and upon determining that the observed channel is busy during the additional CCA slot, deferring a next CCA slot to a next desired CCA slot starting point that is predetermined relative to a subframe boundary or is a subframe boundary, wherein if the observed channel is idle during the additional CCA slot, then decrementing the backoff counter N by one and determining if N is equal to zero; and performing the transmission on the observed channel upon determining that N is equal to zero. observing the observed channel during an additional CCA slot having a CCA duration, T1; and upon determining that the observed channel is busy during the additional CCA slot, deferring a next CCA slot to a next desired CCA slot starting point that is predetermined relative to a subframe boundary or is a subframe boundary, wherein if the observed channel is idle during the additional CCA slot, then decrementing the backoff counter N by one and determining if N is equal to zero; and performing the transmission on the observed channel upon determining that N is equal to zero.