Some demonstrative embodiments include apparatuses, systems and/or methods of communicating in a data group. For example, an apparatus may include logic and circuitry configured to cause Neighbor Awareness Networking (NAN) device to generate a paging message including one or more list elements corresponding to one or more class types, a list element corresponding to a class type to indicate one or more devices of a data group for which data of the class type is pending transmission; to transmit the paging message during a Negotiation time (NT) in a timeblock of the data group; to process a trigger message from a paged device of the data group during a Data Transmission Time (DTxT) following the NT; and, based on the trigger message, to transmit data to the paged device during the DTxT.