One or more devices, systems, and/or methods for utilizing a control resource set comprising a physical downlink control channel and a plurality of resource element group (REG) bundles containing different quantities of resource element groups. An example method for wireless communication comprises forming a first resource region comprising at least a first type of REG bundle and a second type of REG bundle, and performing a control channel transmission using the first resource region. The first type and the second type of REG bundles may comprise different quantities of resource element groups, and the first type and the second type of REG bundles may correspond to candidates of different aggregation levels.