Methods may be provided to operate a network node of a radio access network. Such methods may include transmitting first control information to a wireless terminal, and the first control information may define a frequency resource available for data communication with the wireless terminal over a subframe. After transmitting the first control information, second control information may be transmitted to the wireless terminal. The second control information may define a time resource for a sub-subframe of the subframe. Communication of data may be provided between the network node and the wireless terminal during the sub-subframe of the subframe defined by the frequency resource of the first control information and the time resource of the second control information. Related network nodes and wireless terminals are also discussed.