ink [3,4]. Channel Access Direction Priority Class p min (CWp) max (CWp) T'MCOT (ms) Allowed CWP Sizes Downlink {3,7} {7,15} 8 or 10 {15,31,63} 8 or 10 {15,31,63,127,255,511,1023} Uplink {3,7} {7,15} 6 or 10 {15,31,63,127,255,511,1023} 6 or 10 {15,31,63,127,255,511,1023} access priority class. The downlink burst in the above refers to the continuous transmission by LTE after a successful LBT. For uplink PUSCH transmission, there is no additional restriction on the UE regarding the type of traffic that can be carried in the scheduled sub- frames [10]. LTE Rel-15 further enhanced the uplink transmission in an LAA SCell in the unlicensed spectrum by specifying support for multiple uplink starting and ending point in a subframe, and support for AUL transmission, including channel access mechanisms, core and RF requirements for base stations and UEs, and RRM requirements. The key functionalities introduced in LTE Rel-15 include additional starting and ending points for PUSCH trans- missions on an LAA SCell (starting PUSCH transmission at the slot boundary; ending PUSCH transmission after the third symbol or at the slot boundary; and UE-based selection of the starting point for PUSCH transmission at the subframe or slot boundary depending on successful channel access); AUL access where a UE can be RRC-configured with a set of subframes and HARQ processes that it may use for autonomous PUSCH transmissions [8,11]. The AUL operation is activated and released with DCI format 0A (transmission mode [TM1]) or DCI format 4A (TM2). The UE skips an AUL allocation if there is no data in the uplink buffers. The PRB allocation and MCS as well as DMRS cyclic shift and orthogonal cover code are indicated to the UE via AUL activation DCI. The UE informs the eNB along with each AUL transmission of the selected HARQ-process ID, new data indicator, redundancy version, UE ID, PUSCH starting and ending points, as well as whether the UE-acquired channel occupancy time can be shared with the eNB. The eNB may provide the UE with HARQ feedback