Patent attributes
Methods, systems, and devices for wireless communication are described. A wireless communication system may utilize a listen before talk (LBT) procedure prior to transmission. A base station may perform an enhanced clear channel assessment (eCCA) on one channel and a single clear channel assessment (CCA) on another channel. The base station may then send a grant for a user equipment (UE) to transmit on both channels. The UE may receive the grant, and perform a single CCA on the first channel and an eCCA on the second channel. The UE may then transmit uplink information on both the first channel and the second channel. That is, the base station may send an opportunistic grant for transmitting on the second channel even though it may not have passed eCCA at the base station. The UE may then use the channel if it passes an eCCA.