For wideband operation in the unlicensed spectrum, a network operator may allocate a channel having multiple sub-bands to user equipment. The presently disclosed embodiments enable the user equipment to select one of multiple noncontiguous sub-bands and/or blocks of contiguous sub-bands that are available in the channel, and transmit data over the selected one of the noncontiguous available sub-bands and/or blocks of contiguous available sub-bands. The user equipment may select the one of the noncontiguous available sub-bands and/or blocks of contiguous available sub-bands of the channel based on the largest block of contiguous available sub-bands, the largest grant size, the best signal quality, the greatest estimated throughput, and/or the highest priority level. Moreover, in cases where data is transmitted using contiguous available sub-bands, guard bands disposed in between the contiguous available sub-bands may also be used to transmit data.